diff --git a/src/config/objects.xml b/src/config/objects.xml
index f5ca5cf..4480004 100644
--- a/src/config/objects.xml
+++ b/src/config/objects.xml
@@ -15,6 +15,20 @@
         <field id="personal_discount" group="customer">personalDiscount</field>
         <field id="discount_card_number" group="customer">discountCardNumber</field>
 
+        <field id="id" group="customerCorporate">id</field>
+        <field id="external_id" group="customerCorporate">externalId</field>
+        <field id="nick_name" group="customerCorporate">nickName</field>
+        <field id="vip" group="customerCorporate">vip</field>
+        <field id="bad" group="customerCorporate">bad</field>
+        <field id="custom_fields" group="customerCorporate">customFields</field>
+        <field id="personal_discount" group="customerCorporate">personalDiscount</field>
+        <field id="discount_card_number" group="customerCorporate">discountCardNumber</field>
+        <field id="manager" group="customerCorporate">manager</field>
+        <field id="address" group="customerCorporate">address</field>
+        <field id="main_contact" group="customerCorporate">mainCustomerContact</field>
+        <field id="company.contragent.i_n_n" group="customerCorporate">companyInn</field>
+        <field id="main_company" group="customerCorporate">company</field>
+
         <field id="address.index" group="customerAddress">index</field>
         <field id="address.country" group="customerAddress">country</field>
         <field id="address.region" group="customerAddress">region</field>
@@ -62,6 +76,7 @@
         <field id="shipment_store" group="order">shipmentStore</field>
         <field id="shipment_date" group="order">shipmentDate</field>
         <field id="shipped" group="order">shipped</field>
+        <field id="contact" group="order">contact</field>
         <!--<field id="order_product" group="order">item</field>-->
         <field id="payment" group="order">payment</field>
         <field id="payments.amount" group="order">amount</field>
diff --git a/src/include/abstracts/class-wc-retailcrm-abstract-builder.php b/src/include/abstracts/class-wc-retailcrm-abstract-builder.php
new file mode 100644
index 0000000..a0842b3
--- /dev/null
+++ b/src/include/abstracts/class-wc-retailcrm-abstract-builder.php
@@ -0,0 +1,86 @@
+<?php
+
+/**
+ * Class WC_Retailcrm_Abstract_Builder.
+ */
+abstract class WC_Retailcrm_Abstract_Builder implements WC_Retailcrm_Builder_Interface
+{
+    /** @var array|mixed $data */
+    protected $data;
+
+    /**
+     * @param array|mixed $data
+     *
+     * @return \WC_Retailcrm_Abstract_Builder
+     */
+    public function setData($data)
+    {
+        $this->data = $data;
+        return $this;
+    }
+
+    /**
+     * @return array|mixed
+     */
+    public function getData()
+    {
+        return $this->data;
+    }
+
+    /**
+     * @return $this|\WC_Retailcrm_Builder_Interface
+     */
+    public function reset()
+    {
+        $this->data = array();
+        return $this;
+    }
+
+    /**
+     * Returns key if it's present in data array (or object which implements ArrayAccess).
+     * Returns default value if key is not present in data, or data is not accessible as array.
+     *
+     * @param string $key
+     * @param mixed  $default
+     *
+     * @return mixed
+     */
+    protected function dataValue($key, $default = '')
+    {
+        return self::arrayValue($this->data, $key, $default);
+    }
+
+    /**
+     * Returns key from array if it's present in array
+     *
+     * @param array|\ArrayObject $data
+     * @param mixed              $key
+     * @param string             $default
+     *
+     * @return mixed|string
+     */
+    protected static function arrayValue($data, $key, $default = '')
+    {
+        if (!is_array($data) && !($data instanceof ArrayAccess)) {
+            return $default;
+        }
+
+        if (array_key_exists($key, $data) && !empty($data[$key])) {
+            return $data[$key];
+        }
+
+        return $default;
+    }
+
+    /**
+     * @return \WC_Retailcrm_Builder_Interface
+     */
+    abstract public function build();
+
+    /**
+     * Returns builder result. Should return null if WC_Retailcrm_Abstract_Builder::isBuilt() == false.
+     *
+     * @return mixed|null
+     */
+    abstract public function getResult();
+}
diff --git a/src/include/class-wc-retailcrm-customers.php b/src/include/class-wc-retailcrm-customers.php
index 5690cf1..4caa04c 100644
--- a/src/include/class-wc-retailcrm-customers.php
+++ b/src/include/class-wc-retailcrm-customers.php
@@ -480,7 +480,8 @@ if (!class_exists('WC_Retailcrm_Customers')) :
                             }
                         }
                     } else {
-                        $customer = reset($search['customers']);
+                        $dataCustomers = $search['customers'];
+                        $customer = reset($dataCustomers);
                     }
                 } else {
                     $customer = !empty($search['customer']) ? $search['customer'] : false;
@@ -536,7 +537,8 @@ if (!class_exists('WC_Retailcrm_Customers')) :
                     if ($returnGroup) {
                         return $search['customersCorporate'];
                     } else {
-                        $customer = reset($search['customersCorporate']);
+                        $dataCorporateCustomers = $search['customersCorporate'];
+                        $customer = reset($dataCorporateCustomers);
                     }
                 } elseif (isset($search['customerCorporate'])) {
                     $customer = $search['customerCorporate'];
diff --git a/src/include/class-wc-retailcrm-history.php b/src/include/class-wc-retailcrm-history.php
index 729b037..6d4c100 100644
--- a/src/include/class-wc-retailcrm-history.php
+++ b/src/include/class-wc-retailcrm-history.php
@@ -101,13 +101,14 @@ if ( ! class_exists( 'WC_Retailcrm_History' ) ) :
          * History customers
          *
          * @param string $date
-         * @param int    $since_id
+         * @param int    $sinceId
          *
-         * @return null
+         * @return void
          * @throws \Exception
          */
-        protected function customersHistory($date, $since_id)
+        protected function customersHistory($date, $sinceId)
         {
+<<<<<<< HEAD
             if ($since_id) {
                 $response = $this->retailcrm->customersHistory(array('sinceId' => $since_id));
             } else {
@@ -133,43 +134,73 @@ if ( ! class_exists( 'WC_Retailcrm_History' ) ) :
                     'address.country' => 'billing_country',
                     'address.city' => 'billing_city'
                 );
+=======
+            $filter = array('startDate' => $date);
 
-                foreach ($history as $record) {
-                    if ($record['source'] == 'api' && $record['apiKey']['current'] == true) {
+            if ($sinceId) {
+                $filter = array('sinceId' => $sinceId);
+            }
+
+            $request = new WC_Retailcrm_Paginated_Request();
+            $history = $request
+                ->setApi($this->retailcrm)
+                ->setMethod('customersHistory')
+                ->setParams(array($filter, '{{page}}'))
+                ->setDataKey('history')
+                ->setLimit(100)
+                ->execute()
+                ->getData();
+
+            if (!empty($history)) {
+                $builder = new WC_Retailcrm_WC_Customer_Builder();
+                $lastChange = end($history);
+                $customers = WC_Retailcrm_History_Assembler::assemblyCustomer($history);
+                WC_Retailcrm_Plugin::$history_run = true;
+>>>>>>> WIP: Change client in the order (not ready at this point; also tests should fail)
+
+                foreach ($customers as $crmCustomer) {
+                    if (!isset($crmCustomer['externalId'])) {
                         continue;
                     }
 
-                    if (isset($record['customer']['externalId'])) {
-                        $customer = new WC_Customer($record['customer']['externalId']);
+                    try {
+                        $builder->reset();
 
-                        if ($customer->get_id() == 0) {
+                        if (!$builder->loadExternalId($crmCustomer['externalId'])) {
+                            WC_Retailcrm_Logger::addCaller(__METHOD__, sprintf(
+                                'Customer with id=%s is not found in the DB, skipping...',
+                                $crmCustomer['externalId']
+                            ));
                             continue;
                         }
-                    }
 
-                    WC_Retailcrm_Plugin::$history_run = true;
+                        $wcCustomer = $builder
+                            ->setData($crmCustomer)
+                            ->build()
+                            ->getResult();
 
-                    if (isset($mapping[$record['field']]) && isset($record['customer']['externalId'])) {
-                        if ($record['newValue']) {
-                            if (is_array($mapping[$record['field']])) {
-                                foreach ($mapping[$record['field']] as $mappingField) {
-                                    update_user_meta($record['customer']['externalId'], $mappingField, $record['newValue']);
-                                }
-                            } else {
-                                update_user_meta($record['customer']['externalId'], $mapping[$record['field']], $record['newValue']);
-                            }
+                        if ($wcCustomer instanceof WC_Customer) {
+                            $wcCustomer->save();
                         }
+
+                        WC_Retailcrm_Logger::debug(__METHOD__, 'Updated WC_Customer:', $wcCustomer);
+                    } catch (\Exception $exception) {
+                        WC_Retailcrm_Logger::error(sprintf(
+                            'Error while trying to process history: %s',
+                            $exception->getMessage()
+                        ));
+                        WC_Retailcrm_Logger::error(sprintf(
+                            '%s:%d',
+                            $exception->getFile(),
+                            $exception->getLine()
+                        ));
+                        WC_Retailcrm_Logger::error($exception->getTraceAsString());
                     }
-
-                    WC_Retailcrm_Plugin::$history_run = false;
                 }
-            }
 
-            if (isset($new_since_id)) {
-                update_option('retailcrm_customers_history_since_id', $new_since_id);
+                update_option('retailcrm_customers_history_since_id', $lastChange['id']);
+                WC_Retailcrm_Plugin::$history_run = false;
             }
-
-            return;
         }
 
 	    /**
@@ -182,22 +213,33 @@ if ( ! class_exists( 'WC_Retailcrm_History' ) ) :
 	     */
         protected function ordersHistory($date, $since_id)
         {
+            $filter = array('startDate' => $date);
             $options = array_flip(array_filter($this->retailcrm_settings));
 
             if ($since_id) {
-                $response = $this->retailcrm->ordersHistory(array('sinceId' => $since_id));
-            } else {
-                $response = $this->retailcrm->ordersHistory(array('startDate' => $date));
+                $filter = array('sinceId' => $since_id);
             }
 
+<<<<<<< HEAD
             if (!empty($response) && $response->isSuccessful()) {
                 if (empty($response['history'])) {
                     return false;
                 }
+=======
+            $request = new WC_Retailcrm_Paginated_Request();
+            $history = $request
+                ->setApi($this->retailcrm)
+                ->setMethod('ordersHistory')
+                ->setParams(array($filter, '{{page}}'))
+                ->setDataKey('history')
+                ->setLimit(100)
+                ->execute()
+                ->getData();
+>>>>>>> WIP: Change client in the order (not ready at this point; also tests should fail)
 
-                $history = $response['history'];
+            if (!empty($history)) {
                 $last_change = end($history);
-                $historyAssembly = self::assemblyOrder($response['history']);
+                $historyAssembly = WC_Retailcrm_History_Assembler::assemblyOrder($history);
 
                 WC_Retailcrm_Plugin::$history_run = true;
 
@@ -559,7 +601,7 @@ if ( ! class_exists( 'WC_Retailcrm_History' ) ) :
 
             $customerId = isset($order['customer']['externalId']) ? $order['customer']['externalId'] : null;
 
-            if ($order['customer']['type'] == 'customer_corporate') {
+            if (self::isOrderCorporate($order)) {
                 $customerId = isset($order['contact']['externalId']) ? $order['contact']['externalId'] : null;
             }
 
@@ -573,9 +615,18 @@ if ( ! class_exists( 'WC_Retailcrm_History' ) ) :
             /** @var WC_Order|WP_Error $wc_order */
             $wc_order = wc_create_order($args);
             $customer = $order['customer'];
+            $contactOrCustomer = array();
             $address = isset($order['customer']['address']) ? $order['customer']['address'] : array();
             $companyName = '';
 
+            if (self::isOrderCorporate($order)) {
+                if (isset($order['contact'])) {
+                    $contactOrCustomer = $order['contact'];
+                }
+            } else {
+                $contactOrCustomer = $customer;
+            }
+
             if ($wc_order instanceof WP_Error) {
                 WC_Retailcrm_Logger::add(sprintf(
                     '[%d] error while creating order: %s',
@@ -590,12 +641,12 @@ if ( ! class_exists( 'WC_Retailcrm_History' ) ) :
                 $wc_order->add_order_note($order['managerComment'], 0, false);
             }
 
-            if (isset($order['customer']['type'])
-                && $order['customer']['type'] == 'customer_corporate'
-                && !empty($order['customer']['mainCompany'])
-                && isset($order['customer']['mainCompany']['name'])
+            // TODO Check if that works; also don't forget to set this company field while creating order from CMS!
+            if (self::isOrderCorporate($order)
+                && !empty($order['company'])
+                && isset($order['company']['name'])
             ) {
-                $companyName = $order['customer']['mainCompany']['name'];
+                $companyName = $order['company']['name'];
             }
 
             $address_shipping = array(
@@ -611,11 +662,11 @@ if ( ! class_exists( 'WC_Retailcrm_History' ) ) :
             );
 
             $address_billing = array(
-                'first_name' => $customer['firstName'],
-                'last_name'  => isset($customer['lastName']) ? $customer['lastName'] : '',
+                'first_name' => $contactOrCustomer['firstName'],
+                'last_name'  => isset($contactOrCustomer['lastName']) ? $contactOrCustomer['lastName'] : '',
                 'company'    => $companyName,
                 'email'      => isset($customer['email']) ? $customer['email'] : '',
-                'phone'      => isset($customer['phones'][0]['number']) ? $customer['phones'][0]['number'] : '',
+                'phone'      => isset($contactOrCustomer['phones'][0]['number']) ? $contactOrCustomer['phones'][0]['number'] : '',
                 'address_1'  => isset($address['text']) ? $address['text'] : '',
                 'address_2'  => '',
                 'city'       => isset($address['city']) ? $address['city'] : '',
@@ -872,154 +923,15 @@ if ( ! class_exists( 'WC_Retailcrm_History' ) ) :
         }
 
         /**
-         * @param array $orderHistory
+         * Returns true if provided crm order is corporate
          *
-         * @return array
+         * @param array $order
+         *
+         * @return bool
          */
-        public static function assemblyOrder($orderHistory)
+        private static function isOrderCorporate($order)
         {
-            $fields = array();
-
-            if (file_exists(__DIR__ . '/../config/objects.xml')) {
-                $objects = simplexml_load_file(__DIR__ . '/../config/objects.xml');
-
-                foreach($objects->fields->field as $object) {
-                    $fields[(string)$object["group"]][(string)$object["id"]] = (string)$object;
-                }
-            }
-
-            $orders = array();
-
-            foreach ($orderHistory as $change) {
-                if ($change['source'] == 'api'
-                    && isset($change['apiKey']['current'])
-                    && $change['apiKey']['current'] == true
-                ) {
-                    continue;
-                }
-
-                $change['order'] = self::removeEmpty($change['order']);
-                if(isset($change['order']['items']) && $change['order']['items']) {
-                    $items = array();
-                    foreach($change['order']['items'] as $item) {
-                        if(isset($change['created'])) {
-                            $item['create'] = 1;
-                        }
-                        $items[$item['id']] = $item;
-                    }
-                    $change['order']['items'] = $items;
-                }
-
-                if(isset($change['order']['contragent']['contragentType']) && $change['order']['contragent']['contragentType']) {
-                    $change['order']['contragentType'] = $change['order']['contragent']['contragentType'];
-                    unset($change['order']['contragent']);
-                }
-
-                if (!empty($orders) && isset($orders[$change['order']['id']])) {
-                    $orders[$change['order']['id']] = array_merge($orders[$change['order']['id']], $change['order']);
-                } else {
-                    $orders[$change['order']['id']] = $change['order'];
-                }
-
-                if (isset($change['item']) && $change['item']) {
-                    if(isset($orders[$change['order']['id']]['items'][$change['item']['id']])) {
-                        $orders[$change['order']['id']]['items'][$change['item']['id']] = array_merge($orders[$change['order']['id']]['items'][$change['item']['id']], $change['item']);
-                    } else {
-                        $orders[$change['order']['id']]['items'][$change['item']['id']] = $change['item'];
-                    }
-
-                    if ($change['oldValue'] === null
-                        && $change['field'] == 'order_product'
-                    ) {
-                        $orders[$change['order']['id']]['items'][$change['item']['id']]['create'] = true;
-                    }
-
-                    if ($change['newValue'] === null
-                        && $change['field'] == 'order_product'
-                    ) {
-                        $orders[$change['order']['id']]['items'][$change['item']['id']]['delete'] = true;
-                    }
-
-                    if (!isset($orders[$change['order']['id']]['items'][$change['item']['id']]['create'])
-                        && isset($fields['item'][$change['field']])
-                        && $fields['item'][$change['field']]
-                    ) {
-                        $orders[$change['order']['id']]['items'][$change['item']['id']][$fields['item'][$change['field']]] = $change['newValue'];
-                    }
-                } elseif ($change['field'] == 'payments' && isset($change['payment'])) {
-                    if ($change['newValue'] !== null) {
-                        $orders[$change['order']['id']]['payments'][] = self::newValue($change['payment']);
-                    }
-                }  else {
-                    if (isset($fields['delivery'][$change['field']]) && $fields['delivery'][$change['field']] == 'service') {
-                        $orders[$change['order']['id']]['delivery']['service']['code'] = self::newValue($change['newValue']);
-                    } elseif (isset($fields['delivery'][$change['field']]) && $fields['delivery'][$change['field']]) {
-                        $orders[$change['order']['id']]['delivery'][$fields['delivery'][$change['field']]] = self::newValue($change['newValue']);
-                    } elseif (isset($fields['orderAddress'][$change['field']]) && $fields['orderAddress'][$change['field']]) {
-                        $orders[$change['order']['id']]['delivery']['address'][$fields['orderAddress'][$change['field']]] = $change['newValue'];
-                    } elseif (isset($fields['integrationDelivery'][$change['field']]) && $fields['integrationDelivery'][$change['field']]) {
-                        $orders[$change['order']['id']]['delivery']['service'][$fields['integrationDelivery'][$change['field']]] = self::newValue($change['newValue']);
-                    } elseif (isset($fields['customerContragent'][$change['field']]) && $fields['customerContragent'][$change['field']]) {
-                        $orders[$change['order']['id']][$fields['customerContragent'][$change['field']]] = self::newValue($change['newValue']);
-                    } elseif (strripos($change['field'], 'custom_') !== false) {
-                        $orders[$change['order']['id']]['customFields'][str_replace('custom_', '', $change['field'])] = self::newValue($change['newValue']);
-                    } elseif (isset($fields['order'][$change['field']]) && $fields['order'][$change['field']]) {
-                        $orders[$change['order']['id']][$fields['order'][$change['field']]] = self::newValue($change['newValue']);
-                    }
-
-                    if (isset($change['created'])) {
-                        $orders[$change['order']['id']]['create'] = 1;
-                    }
-
-                    if (isset($change['deleted'])) {
-                        $orders[$change['order']['id']]['deleted'] = 1;
-                    }
-                }
-            }
-
-            return $orders;
-        }
-
-        public static function assemblyCustomer($customerHistory)
-        {
-            $customers = array();
-            foreach ($customerHistory as $change) {
-                $change['order'] = self::removeEmpty($change['customer']);
-
-                if (!empty($customers[$change['customer']['id']]) && $customers[$change['customer']['id']]) {
-                    $customers[$change['customer']['id']] = array_merge($customers[$change['customer']['id']], $change['customer']);
-                } else {
-                    $customers[$change['customer']['id']] = $change['customer'];
-                }
-            }
-
-            return $customers;
-        }
-
-        public static function newValue($value)
-        {
-            if (isset($value['code'])) {
-                return $value['code'];
-            } else {
-                return $value;
-            }
-        }
-
-        public static function removeEmpty($inputArray)
-        {
-            $outputArray = array();
-            if (!empty($inputArray)) {
-                foreach ($inputArray as $key => $element) {
-                    if(!empty($element) || $element === 0 || $element === '0'){
-                        if (is_array($element)) {
-                            $element = self::removeEmpty($element);
-                        }
-                        $outputArray[$key] = $element;
-                    }
-                }
-            }
-
-            return $outputArray;
+            return isset($order['customer']['type']) && $order['customer']['type'] == 'customer_corporate';
         }
     }
 
diff --git a/src/include/class-wc-retailcrm-plugin.php b/src/include/class-wc-retailcrm-plugin.php
index f66761d..ea5722a 100644
--- a/src/include/class-wc-retailcrm-plugin.php
+++ b/src/include/class-wc-retailcrm-plugin.php
@@ -164,7 +164,6 @@ class WC_Retailcrm_Plugin {
         return $result;
     }
 
-
     /**
      * Check running history
      *
diff --git a/src/include/components/class-wc-retailcrm-customer-data-replacer.php b/src/include/components/class-wc-retailcrm-customer-data-replacer.php
new file mode 100644
index 0000000..ec9eee7
--- /dev/null
+++ b/src/include/components/class-wc-retailcrm-customer-data-replacer.php
@@ -0,0 +1,152 @@
+<?php
+
+/**
+ * Class WC_Retailcrm_Customer_Data_Replacer
+ * This component provides builder-like interface in order to make it easier to change customer & customer data
+ * in the order via retailCRM history.
+ */
+class WC_Retailcrm_Customer_Data_Replacer implements WC_Retailcrm_Builder_Interface
+{
+    /**
+     * @var \WC_Retailcrm_Customer_Data_Replacer_State $data
+     */
+    private $data;
+
+    /**
+     * @var \WC_Retailcrm_Customer_Data_Replacer_Result|null $result
+     */
+    private $result;
+
+    /**
+     * WC_Retailcrm_Customer_Data_Replacer constructor.
+     */
+    public function __construct()
+    {
+        $this->reset();
+    }
+
+    /**
+     * In fact, this will execute customer change in provided order.
+     * This will not build anything.
+     *
+     * @return $this|\WC_Retailcrm_Builder_Interface
+     */
+    public function build()
+    {
+        $this->data->validate();
+
+        $wcOrder = $this->data->getWcOrder();
+        $newCustomer = $this->data->getNewCustomer();
+        $newCorporateCustomer = $this->data->getNewCorporateCustomer();
+        $newContact = $this->data->getNewContact();
+        $newCompany = $this->data->getNewCompany();
+
+        if (!empty($newCustomer)) {
+            $this->processChangeToRegular($wcOrder, $newCustomer);
+            return $this;
+        }
+
+        if (!empty($newContact)) {
+            $this->processChangeToContactPerson($wcOrder, $newContact);
+        }
+
+        if (!empty($newCompany)) {
+            $this->updateCompany($wcOrder, $newCorporateCustomer, $newCompany);
+        }
+
+        return $this;
+    }
+
+    /**
+     * Change order customer to regular one
+     *
+     * @param \WC_Order $wcOrder
+     * @param array $newCustomer
+     */
+    public function processChangeToRegular($wcOrder, $newCustomer)
+    {
+        // TODO: Implement
+    }
+
+    /**
+     * Change order customer to corporate one (we only care about it's contact)
+     *
+     * @param \WC_Order $wcOrder
+     * @param array $newContact
+     */
+    public function processChangeToContactPerson($wcOrder, $newContact)
+    {
+        // TODO: Implement
+    }
+
+    /**
+     * Update company in the order
+     *
+     * @param WC_Order $wcOrder
+     * @param array $corporateCustomer
+     * @param array $company
+     */
+    public function updateCompany($wcOrder, $corporateCustomer, $company)
+    {
+        // TODO: Implement
+    }
+
+    /**
+     * @return $this|\WC_Retailcrm_Builder_Interface
+     */
+    public function reset()
+    {
+        $this->data = new WC_Retailcrm_Customer_Data_Replacer_State();
+        $this->result = null;
+        return $this;
+    }
+
+    /**
+     * Set initial state into component
+     *
+     * @param \WC_Retailcrm_Customer_Data_Replacer_State $data
+     *
+     * @return $this|\WC_Retailcrm_Builder_Interface
+     */
+    public function setData($data)
+    {
+        if (!($data instanceof WC_Retailcrm_Customer_Data_Replacer_State)) {
+            throw new \InvalidArgumentException('Invalid data type');
+        }
+
+        $this->data = $data;
+        return $this;
+    }
+
+    /**
+     * @return \WC_Retailcrm_Customer_Data_Replacer_Result|null
+     */
+    public function getResult()
+    {
+        return $this->result;
+    }
+
+    /**
+     * @return \WC_Retailcrm_Customer_Data_Replacer_State
+     */
+    public function getData()
+    {
+        return $this->data;
+    }
+
+    /**
+     * Returns WC_Customer by id. Returns null if there's no such customer.
+     *
+     * @param int $id
+     *
+     * @return \WC_Customer|null
+     */
+    private function getWcCustomerById($id)
+    {
+        try {
+            return new WC_Customer($id);
+        } catch (\Exception $exception) {
+            return null;
+        }
+    }
+}
diff --git a/src/include/components/class-wc-retailcrm-history-assembler.php b/src/include/components/class-wc-retailcrm-history-assembler.php
new file mode 100644
index 0000000..85ffe09
--- /dev/null
+++ b/src/include/components/class-wc-retailcrm-history-assembler.php
@@ -0,0 +1,402 @@
+<?php
+
+/**
+ * Class WC_Retailcrm_History_Assembler
+ * Assembles history records into list which closely resembles orders & customers list output from API.
+ */
+class WC_Retailcrm_History_Assembler
+{
+    /**
+     * Assembles orders list from history data
+     *
+     * @param array $orderHistory
+     *
+     * @return array
+     */
+    public static function assemblyOrder($orderHistory)
+    {
+        $fields = self::getMappingValues();
+        $orders = array();
+        $orderHistory = self::filterHistory($orderHistory, 'order');
+
+        foreach ($orderHistory as $change) {
+            $change['order'] = self::removeEmpty($change['order']);
+
+            if(isset($change['order']['items']) && $change['order']['items']) {
+                $items = array();
+                foreach($change['order']['items'] as $item) {
+                    if(isset($change['created'])) {
+                        $item['create'] = 1;
+                    }
+                    $items[$item['id']] = $item;
+                }
+                $change['order']['items'] = $items;
+            }
+
+            if(isset($change['order']['contragent']['contragentType']) && $change['order']['contragent']['contragentType']) {
+                $change['order']['contragentType'] = $change['order']['contragent']['contragentType'];
+                unset($change['order']['contragent']);
+            }
+
+            if (!empty($orders) && isset($orders[$change['order']['id']])) {
+                $orders[$change['order']['id']] = array_merge($orders[$change['order']['id']], $change['order']);
+            } else {
+                $orders[$change['order']['id']] = $change['order'];
+            }
+
+            if (isset($change['item']) && $change['item']) {
+                if(isset($orders[$change['order']['id']]['items'][$change['item']['id']])) {
+                    $orders[$change['order']['id']]['items'][$change['item']['id']] = array_merge($orders[$change['order']['id']]['items'][$change['item']['id']], $change['item']);
+                } else {
+                    $orders[$change['order']['id']]['items'][$change['item']['id']] = $change['item'];
+                }
+
+                if ($change['oldValue'] === null
+                    && $change['field'] == 'order_product'
+                ) {
+                    $orders[$change['order']['id']]['items'][$change['item']['id']]['create'] = true;
+                }
+
+                if ($change['newValue'] === null
+                    && $change['field'] == 'order_product'
+                ) {
+                    $orders[$change['order']['id']]['items'][$change['item']['id']]['delete'] = true;
+                }
+
+                if (!isset($orders[$change['order']['id']]['items'][$change['item']['id']]['create'])
+                    && isset($fields['item'][$change['field']])
+                    && $fields['item'][$change['field']]
+                ) {
+                    $orders[$change['order']['id']]['items'][$change['item']['id']][$fields['item'][$change['field']]] = $change['newValue'];
+                }
+            } elseif ($change['field'] == 'payments' && isset($change['payment'])) {
+                if ($change['newValue'] !== null) {
+                    $orders[$change['order']['id']]['payments'][] = self::newValue($change['payment']);
+                }
+            }  else {
+                if (isset($fields['delivery'][$change['field']]) && $fields['delivery'][$change['field']] == 'service') {
+                    $orders[$change['order']['id']]['delivery']['service']['code'] = self::newValue($change['newValue']);
+                } elseif (isset($fields['delivery'][$change['field']]) && $fields['delivery'][$change['field']]) {
+                    $orders[$change['order']['id']]['delivery'][$fields['delivery'][$change['field']]] = self::newValue($change['newValue']);
+                } elseif (isset($fields['orderAddress'][$change['field']]) && $fields['orderAddress'][$change['field']]) {
+                    $orders[$change['order']['id']]['delivery']['address'][$fields['orderAddress'][$change['field']]] = $change['newValue'];
+                } elseif (isset($fields['integrationDelivery'][$change['field']]) && $fields['integrationDelivery'][$change['field']]) {
+                    $orders[$change['order']['id']]['delivery']['service'][$fields['integrationDelivery'][$change['field']]] = self::newValue($change['newValue']);
+                } elseif (isset($fields['customerContragent'][$change['field']]) && $fields['customerContragent'][$change['field']]) {
+                    $orders[$change['order']['id']][$fields['customerContragent'][$change['field']]] = self::newValue($change['newValue']);
+                } elseif (strripos($change['field'], 'custom_') !== false) {
+                    $orders[$change['order']['id']]['customFields'][str_replace('custom_', '', $change['field'])] = self::newValue($change['newValue']);
+                } elseif (isset($fields['order'][$change['field']]) && $fields['order'][$change['field']]) {
+                    $orders[$change['order']['id']][$fields['order'][$change['field']]] = self::newValue($change['newValue']);
+                }
+
+                if (isset($change['created'])) {
+                    $orders[$change['order']['id']]['create'] = 1;
+                }
+
+                if (isset($change['deleted'])) {
+                    $orders[$change['order']['id']]['deleted'] = 1;
+                }
+            }
+        }
+
+        return $orders;
+    }
+
+    /**
+     * Assembles customers list from history changes
+     *
+     * @param array $customerHistory
+     *
+     * @return array
+     */
+    public static function assemblyCustomer($customerHistory)
+    {
+        $customers = array();
+        $fields = self::getMappingValues(array('customer'));
+        $fieldsAddress = self::getMappingValues(array('customerAddress'));
+        $customerHistory = self::filterHistory($customerHistory, 'customer');
+
+        foreach ($customerHistory as $change) {
+            $change['customer'] = self::removeEmpty($change['customer']);
+
+            if (isset($change['deleted'])
+                && $change['deleted']
+                && isset($customers[$change['customer']['id']])
+            ) {
+                $customers[$change['customer']['id']]['deleted'] = true;
+                continue;
+            }
+
+            if ($change['field'] == 'id') {
+                $customers[$change['customer']['id']] = $change['customer'];
+            }
+
+            if (isset($customers[$change['customer']['id']])) {
+                $customers[$change['customer']['id']] = array_merge($customers[$change['customer']['id']], $change['customer']);
+            } else {
+                $customers[$change['customer']['id']] = $change['customer'];
+            }
+
+            if (isset($fields['customer'][$change['field']])
+                && $fields['customer'][$change['field']]
+            ) {
+                $customers[
+                    $change['customer']['id']
+                ][
+                    $fields['customer'][$change['field']]
+                ] = self::newValue($change['newValue']);
+            }
+
+            if (isset($fieldsAddress['customerAddress'][$change['field']])
+                && $fieldsAddress['customerAddress'][$change['field']]
+            ) {
+                if (!isset($customers[$change['customer']['id']]['address'])) {
+                    $customers[$change['customer']['id']]['address'] = array();
+                }
+
+                $customers[
+                    $change['customer']['id']
+                ][
+                    'address'
+                ][
+                    $fieldsAddress['customerAddress'][$change['field']]
+                ] = self::newValue($change['newValue']);
+            }
+
+            // email_marketing_unsubscribed_at old value will be null and new value will be datetime in
+            // `Y-m-d H:i:s` format if customer was marked as unsubscribed in retailCRM
+            if (isset($change['customer']['id']) &&
+                $change['field'] == 'email_marketing_unsubscribed_at'
+            ) {
+                if ($change['oldValue'] == null && is_string(self::newValue($change['newValue']))) {
+                    $customers[$change['customer']['id']]['subscribed'] = false;
+                } elseif (is_string($change['oldValue']) && self::newValue($change['newValue']) == null) {
+                    $customers[$change['customer']['id']]['subscribed'] = true;
+                }
+            }
+        }
+
+        return $customers;
+    }
+
+    /**
+     * Assembles corporate customers list from changes
+     *
+     * @param array $customerHistory
+     *
+     * @return array
+     */
+    public static function assemblyCorporateCustomer($customerHistory)
+    {
+        $fields = self::getMappingValues(array('customerCorporate', 'customerAddress'));
+        $customersCorporate = array();
+
+        foreach ($customerHistory as $change) {
+            $change['customer'] = self::removeEmpty($change['customer']);
+
+            if (isset($change['deleted'])
+                && $change['deleted']
+                && isset($customersCorporate[$change['customer']['id']])
+            ) {
+                $customersCorporate[$change['customer']['id']]['deleted'] = true;
+                continue;
+            }
+
+            if (isset($customersCorporate[$change['customer']['id']])) {
+                if (isset($customersCorporate[$change['customer']['id']]['deleted'])
+                    && $customersCorporate[$change['customer']['id']]['deleted']
+                ) {
+                    continue;
+                }
+
+                $customersCorporate[$change['customer']['id']] = array_merge(
+                    $customersCorporate[$change['customer']['id']],
+                    $change['customer']
+                );
+            } else {
+                $customersCorporate[$change['customer']['id']] = $change['customer'];
+            }
+
+            if (isset($fields['customerCorporate'][$change['field']])
+                && $fields['customerCorporate'][$change['field']]
+            ) {
+                $customersCorporate[
+                    $change['customer']['id']
+                ][
+                    $fields['customerCorporate'][$change['field']]
+                ] = self::newValue($change['newValue']);
+            }
+
+            if (isset($fields['customerAddress'][$change['field']])
+                && $fields['customerAddress'][$change['field']]
+            ) {
+                if (empty($customersCorporate[$change['customer']['id']]['address'])) {
+                    $customersCorporate[$change['customer']['id']]['address'] = array();
+                }
+
+                $customersCorporate[
+                    $change['customer']['id']
+                ][
+                    'address'
+                ][
+                    $fields['customerAddress'][$change['field']]
+                ] = self::newValue($change['newValue']);
+            }
+
+            if ($change['field'] == 'address') {
+                $customersCorporate[
+                    $change['customer']['id']
+                ]['address'] = array_merge($change['address'], self::newValue($change['newValue']));
+            }
+        }
+
+        foreach ($customersCorporate as $id => &$customer) {
+            if (empty($customer['id']) && !empty($id)) {
+                $customer['id'] = $id;
+                $customer['deleted'] = true;
+            }
+        }
+
+        return $customersCorporate;
+    }
+
+    /**
+     * Returns mapping data for retailCRM entities. Used to assembly entities from history.
+     *
+     * @param array $groupFilter
+     *
+     * @return array
+     */
+    private static function getMappingValues($groupFilter = array())
+    {
+        $fields = array();
+        $mappingFile = implode(
+            DIRECTORY_SEPARATOR,
+            array(WP_CONTENT_DIR, 'plugins', 'woo-retailcrm', 'config', 'objects.xml')
+        );
+
+        if (file_exists($mappingFile)) {
+            $objects = simplexml_load_file($mappingFile);
+
+            foreach($objects->fields->field as $object) {
+                if (empty($groupFilter) || in_array($object["group"], $groupFilter)) {
+                    $fields[(string)$object["group"]][(string)$object["id"]] = (string)$object;
+                }
+            }
+        }
+
+        return $fields;
+    }
+
+    /**
+     * Value accessor
+     *
+     * @param array $value
+     *
+     * @return mixed
+     */
+    private static function newValue($value)
+    {
+        if (isset($value['code'])) {
+            return $value['code'];
+        } else {
+            return $value;
+        }
+    }
+
+    /**
+     * Returns array without values which are considered empty
+     *
+     * @param array|\ArrayAccess $inputArray
+     *
+     * @return array
+     */
+    private static function removeEmpty($inputArray)
+    {
+        $outputArray = array();
+
+        if (!empty($inputArray)) {
+            foreach ($inputArray as $key => $element) {
+                if(!empty($element) || $element === 0 || $element === '0'){
+                    if (is_array($element)) {
+                        $element = self::removeEmpty($element);
+                    }
+
+                    $outputArray[$key] = $element;
+                }
+            }
+        }
+
+        return $outputArray;
+    }
+
+    /**
+     * Filters out history by these terms:
+     *  - Changes from current API key will be added only if CMS changes are more actual than history.
+     *  - All other changes will be merged as usual.
+     * It fixes these problems:
+     *  - Changes from current API key are merged when it's not needed.
+     *  - Changes from CRM can overwrite more actual changes from CMS due to ignoring current API key changes.
+     *
+     * @param array  $historyEntries Raw history from CRM
+     * @param string $recordType     Entity field name, e.g. `customer` or `order`.
+     *
+     * @return array
+     */
+    private static function filterHistory($historyEntries, $recordType)
+    {
+        $history = array();
+        $organizedHistory = array();
+        $notOurChanges = array();
+
+        foreach ($historyEntries as $entry) {
+            if (!isset($entry[$recordType]['externalId'])) {
+                if ($entry['source'] == 'api'
+                    && isset($change['apiKey']['current'])
+                    && $entry['apiKey']['current'] == true
+                    && $entry['field'] != 'externalId'
+                ) {
+                    continue;
+                } else {
+                    $history[] = $entry;
+                }
+
+                continue;
+            }
+
+            $externalId = $entry[$recordType]['externalId'];
+            $field = $entry['field'];
+
+            if (!isset($organizedHistory[$externalId])) {
+                $organizedHistory[$externalId] = array();
+            }
+
+            if (!isset($notOurChanges[$externalId])) {
+                $notOurChanges[$externalId] = array();
+            }
+
+            if ($entry['source'] == 'api'
+                && isset($entry['apiKey']['current'])
+                && $entry['apiKey']['current'] == true
+            ) {
+                if (isset($notOurChanges[$externalId][$field]) || $entry['field'] == 'externalId') {
+                    $organizedHistory[$externalId][] = $entry;
+                } else {
+                    continue;
+                }
+            } else {
+                $organizedHistory[$externalId][] = $entry;
+                $notOurChanges[$externalId][$field] = true;
+            }
+        }
+
+        unset($notOurChanges);
+
+        foreach ($organizedHistory as $historyChunk) {
+            $history = array_merge($history, $historyChunk);
+        }
+
+        return $history;
+    }
+}
\ No newline at end of file
diff --git a/src/include/class-wc-retailcrm-logger.php b/src/include/components/class-wc-retailcrm-logger.php
similarity index 50%
rename from src/include/class-wc-retailcrm-logger.php
rename to src/include/components/class-wc-retailcrm-logger.php
index 90816eb..319ecb4 100644
--- a/src/include/class-wc-retailcrm-logger.php
+++ b/src/include/components/class-wc-retailcrm-logger.php
@@ -52,24 +52,60 @@ if (!class_exists('WC_Retailcrm_Logger') && class_exists('WC_Log_Levels')):
         }
 
         /**
-         * Debug logging. Contains a lot of debug data like full requests & responses.
+         * Regular logging with caller prefix
          *
-         * @param string $method
+         * @param string $caller
          * @param string $message
          * @param string $level
          */
-        public static function debug($method, $message, $level = WC_Log_Levels::DEBUG)
+        public static function addCaller($caller, $message, $level = WC_Log_Levels::NOTICE)
+        {
+            self::add(sprintf('<%s> => %s', $caller, $message), $level);
+        }
+
+        /**
+         * Log error
+         *
+         * @param string $message
+         */
+        public static function error($message)
+        {
+            self::add($message, WC_Log_Levels::ERROR);
+        }
+
+        /**
+         * Debug logging. Contains a lot of debug data like full requests & responses.
+         * This log will work only if debug mode is enabled (see retailcrm_is_debug() for details).
+         * Caller should be specified, or message will be ignored at all.
+         *
+         * @param string $method
+         * @param array  $messages
+         */
+        public static function debug($method, ...$messages)
         {
             if (retailcrm_is_debug()) {
-                if (!empty($method)) {
-                    $message = sprintf(
-                        '<%s> => %s',
-                        $method,
-                        $message
+                if (!empty($method) && !empty($messages)) {
+                    $result = substr(
+                        array_reduce(
+                            $messages,
+                            function ($carry, $item) {
+                                $carry .= ' ' . print_r($item, true);
+                                return $carry;
+                            }
+                        ),
+                        1
+                    );
+
+                    self::getInstance()->add(
+                        self::HANDLE . '_debug',
+                        sprintf(
+                            '<%s> => %s',
+                            $method,
+                            $result
+                        ),
+                        WC_Log_Levels::DEBUG
                     );
                 }
-
-                self::getInstance()->add(self::HANDLE . '_debug', $message, $level);
             }
         }
     }
diff --git a/src/include/components/class-wc-retailcrm-paginated-request.php b/src/include/components/class-wc-retailcrm-paginated-request.php
new file mode 100644
index 0000000..9c5fa28
--- /dev/null
+++ b/src/include/components/class-wc-retailcrm-paginated-request.php
@@ -0,0 +1,188 @@
+<?php
+
+/**
+ * Class WC_Retailcrm_Paginated_Request
+ * It will merge request with pagination data into one big monstrous array.
+ * Use with caution, it can cause problems with very large data sets (due to memory exhaustion, obviously).
+ */
+class WC_Retailcrm_Paginated_Request
+{
+    /**
+     * @var \WC_Retailcrm_Proxy|\WC_Retailcrm_Client_V5
+     */
+    private $api;
+
+    /**
+     * @var string
+     */
+    private $method;
+
+    /**
+     * @var array
+     */
+    private $params;
+
+    /**
+     * @var string
+     */
+    private $dataKey;
+
+    /**
+     * @var int
+     */
+    private $limit;
+
+    /**
+     * @var array
+     */
+    private $data;
+
+    /**
+     * WC_Retailcrm_Paginated_Request constructor.
+     */
+    public function __construct()
+    {
+        $this->reset();
+    }
+
+    /**
+     * Sets retailCRM api client to request
+     *
+     * @param \WC_Retailcrm_Proxy|\WC_Retailcrm_Client_V5 $api
+     *
+     * @return self
+     */
+    public function setApi($api)
+    {
+        $this->api = $api;
+        return $this;
+    }
+
+    /**
+     * Sets API client method to request
+     *
+     * @param string $method
+     *
+     * @return self
+     */
+    public function setMethod($method)
+    {
+        $this->method = $method;
+        return $this;
+    }
+
+    /**
+     * Sets method params for API client (leave `{{page}}` instead of page and `{{limit}}` instead of limit)
+     *
+     * @param array $params
+     *
+     * @return self
+     */
+    public function setParams($params)
+    {
+        $this->params = $params;
+        return $this;
+    }
+
+    /**
+     * Sets dataKey (key with data in response)
+     *
+     * @param string $dataKey
+     *
+     * @return self
+     */
+    public function setDataKey($dataKey)
+    {
+        $this->dataKey = $dataKey;
+        return $this;
+    }
+
+    /**
+     * Sets record limit per request
+     *
+     * @param int $limit
+     *
+     * @return self
+     */
+    public function setLimit($limit)
+    {
+        $this->limit = $limit;
+        return $this;
+    }
+
+    /**
+     * Executes request
+     *
+     * @return $this
+     */
+    public function execute()
+    {
+        $this->data = array();
+        $response = true;
+        $page = 1;
+
+        do {
+            $response = call_user_func_array(
+                array($this->api, $this->method),
+                $this->buildParams($this->params, $page)
+            );
+
+            if ($response instanceof WC_Retailcrm_Response && $response->offsetExists($this->dataKey)) {
+                $this->data = array_merge($response[$this->dataKey]);
+                $page = $response['pagination']['currentPage'] + 1;
+            }
+
+            time_nanosleep(0, 300000000);
+        } while ($response && (isset($response['pagination'])
+            && $response['pagination']['currentPage'] < $response['pagination']['totalPageCount']));
+
+        return $this;
+    }
+
+    /**
+     * Returns data
+     *
+     * @return array
+     */
+    public function getData()
+    {
+        return $this->data;
+    }
+
+    /**
+     * Reset paginated request
+     *
+     * @return $this
+     */
+    public function reset()
+    {
+        $this->method = '';
+        $this->limit = 100;
+        $this->data = array();
+
+        return $this;
+    }
+
+    /**
+     * buildParams
+     *
+     * @param array $placeholderParams
+     * @param int   $currentPage
+     *
+     * @return mixed
+     */
+    private function buildParams($placeholderParams, $currentPage)
+    {
+        foreach ($placeholderParams as $key => $param) {
+            if ($param == '{{page}}') {
+                $placeholderParams[$key] = $currentPage;
+            }
+
+            if ($param == '{{limit}}') {
+                $placeholderParams[$key] = $this->limit;
+            }
+        }
+
+        return $placeholderParams;
+    }
+}
diff --git a/src/include/customer/woocommerce/class-wc-retailcrm-wc-customer-builder.php b/src/include/customer/woocommerce/class-wc-retailcrm-wc-customer-builder.php
new file mode 100644
index 0000000..f65cf77
--- /dev/null
+++ b/src/include/customer/woocommerce/class-wc-retailcrm-wc-customer-builder.php
@@ -0,0 +1,235 @@
+<?php
+
+/**
+ * Class WC_Retailcrm_WC_Customer_Builder
+ * It converts retailCRM customer data (array) into WC_Customer
+ */
+class WC_Retailcrm_WC_Customer_Builder extends WC_Retailcrm_Abstract_Builder
+{
+    /**
+     * @var \WC_Customer $customer
+     */
+    private $customer;
+
+    /**
+     * WC_Retailcrm_WC_Customer_Builder constructor.
+     */
+    public function __construct()
+    {
+        $this->reset();
+    }
+
+    /**
+     * @param string $firstName
+     *
+     * @return $this
+     */
+    public function setFirstName($firstName)
+    {
+        $this->data['firstName'] = $firstName;
+        return $this;
+    }
+
+    /**
+     * @param string $lastName
+     *
+     * @return $this
+     */
+    public function setLastName($lastName)
+    {
+        $this->data['lastName'] = $lastName;
+        return $this;
+    }
+
+    /**
+     * @param string $email
+     *
+     * @return $this
+     */
+    public function setEmail($email)
+    {
+        $this->data['email'] = $email;
+        return $this;
+    }
+
+    /**
+     * @param string $externalId
+     *
+     * @return $this
+     */
+    public function setExternalId($externalId)
+    {
+        $this->data['externalId'] = $externalId;
+        return $this;
+    }
+
+    /**
+     * @param array $phones
+     *
+     * @return $this
+     */
+    public function setPhones($phones)
+    {
+        if (self::isPhonesArrayValid($phones)) {
+            $this->data['phones'] = $phones;
+        }
+
+        return $this;
+    }
+
+    /**
+     * @param array $address
+     *
+     * @return $this
+     */
+    public function setAddress($address)
+    {
+        if (is_array($address)) {
+            $this->data['address'] = $address;
+        }
+
+        return $this;
+    }
+
+    /**
+     * @param \WC_Customer $customer
+     *
+     * @return $this
+     */
+    public function setWcCustomer($customer)
+    {
+        if ($customer instanceof WC_Customer) {
+            $this->customer = $customer;
+        }
+
+        return $this;
+    }
+
+    /**
+     * Sets provided externalId and loads associated customer from DB (it it exists there).
+     * Returns true if everything went find; returns false if customer wasn't found.
+     *
+     * @param string $externalId
+     *
+     * @return bool
+     * @throws \Exception
+     */
+    public function loadExternalId($externalId)
+    {
+        try {
+            $wcCustomer = new WC_Customer($externalId);
+        } catch (\Exception $exception) {
+            return false;
+        }
+
+        $this->setExternalId($externalId);
+        $this->setWcCustomer($wcCustomer);
+
+        return true;
+    }
+
+    public function reset()
+    {
+        parent::reset();
+        $this->customer = new WC_Customer();
+
+        return $this;
+    }
+
+    /**
+     * Fill WC_Customer fields with customer data from retailCRM.
+     * If field is not present in retailCRM customer - it will remain unchanged.
+     *
+     * @return $this|\WC_Retailcrm_Builder_Interface
+     */
+    public function build()
+    {
+        $this->checkBuilderValidity();
+        WC_Retailcrm_Logger::debug(__METHOD__, 'Building WC_Customer from data:', $this->data);
+        $this->customer->set_first_name($this->dataValue('firstName', $this->customer->get_first_name()));
+        $this->customer->set_last_name($this->dataValue('lastName', $this->customer->get_last_name()));
+        $this->customer->set_billing_email($this->dataValue('email', $this->customer->get_billing_email()));
+        $phones = $this->dataValue('phones', array());
+
+        if (count($phones) > 0) {
+            $phoneData = reset($phones);
+
+            if (is_array($phoneData) && isset($phoneData['number'])) {
+                $this->customer->set_billing_phone($phoneData['number']);
+            }
+        }
+
+        if (!empty($this->dataValue('address'))) {
+            $address = $this->dataValue('address');
+
+            $this->customer->set_billing_state(self::arrayValue(
+                $address,
+                'region',
+                $this->customer->get_billing_state())
+            );
+            $this->customer->set_billing_postcode(self::arrayValue(
+                $address,
+                'index',
+                $this->customer->get_billing_postcode())
+            );
+            $this->customer->set_billing_country(self::arrayValue(
+                $address,
+                'country',
+                $this->customer->get_billing_country())
+            );
+            $this->customer->set_billing_city(self::arrayValue(
+                $address,
+                'city',
+                $this->customer->get_billing_city())
+            );
+        }
+
+        return $this;
+    }
+
+    /**
+     * @return mixed|\WC_Customer|null
+     */
+    public function getResult()
+    {
+        return $this->customer;
+    }
+
+    /**
+     * Throws an exception if internal state is not ready for data building.
+     *
+     * @throws \RuntimeException
+     */
+    private function checkBuilderValidity()
+    {
+        if (empty($this->data)) {
+            throw new \RuntimeException('Empty data');
+        }
+
+        if (!is_array($this->data)) {
+            throw new \RuntimeException('Data must be an array');
+        }
+    }
+
+    /**
+     * Returns true if provided variable contains array with customer phones.
+     *
+     * @param mixed $phones
+     *
+     * @return bool
+     */
+    private static function isPhonesArrayValid($phones)
+    {
+        if (!is_array($phones)) {
+            return false;
+        }
+
+        foreach ($phones as $phone) {
+            if (!is_array($phone) || count($phone) != 1 || !array_key_exists('number', $phone)) {
+                return false;
+            }
+        }
+
+        return true;
+    }
+}
diff --git a/src/include/customer/woocommerce/class-wc-retailcrm-wc-customer-corporate-builder.php b/src/include/customer/woocommerce/class-wc-retailcrm-wc-customer-corporate-builder.php
new file mode 100644
index 0000000..784ffd7
--- /dev/null
+++ b/src/include/customer/woocommerce/class-wc-retailcrm-wc-customer-corporate-builder.php
@@ -0,0 +1,248 @@
+<?php
+
+/**
+ * Class WC_Retailcrm_WC_Customer_Corporate_Builder
+ * It converts retailCRM customer data (array) into WC_Customer
+ */
+class WC_Retailcrm_WC_Customer_Corporate_Builder extends WC_Retailcrm_Abstract_Builder
+{
+    /**
+     * @var \WC_Customer $customer
+     */
+    private $customer;
+
+    /**
+     * @var array $contactPerson
+     */
+    private $contactPerson;
+
+    /**
+     * @var \WC_Retailcrm_Builder_Interface $customerBuilder
+     */
+    private $customerBuilder;
+    
+    /**
+     * WC_Retailcrm_WC_Customer_Builder constructor.
+     */
+    public function __construct()
+    {
+        $this->reset();
+    }
+
+    /**
+     * @param array $contactPerson
+     *
+     * @return \WC_Retailcrm_WC_Customer_Corporate_Builder
+     */
+    public function setContactPerson($contactPerson)
+    {
+        $this->contactPerson = $contactPerson;
+        return $this;
+    }
+
+    /**
+     * @return array
+     */
+    public function getContactPerson()
+    {
+        return $this->contactPerson;
+    }
+
+    /**
+     * @param \WC_Retailcrm_Builder_Interface $customerBuilder
+     */
+    public function setCustomerBuilder($customerBuilder)
+    {
+        $this->customerBuilder = $customerBuilder;
+    }
+
+    /**
+     * @param string $firstName
+     *
+     * @return $this
+     */
+    public function setFirstName($firstName)
+    {
+        $this->contactPerson['firstName'] = $firstName;
+        return $this;
+    }
+
+    /**
+     * @param string $lastName
+     *
+     * @return $this
+     */
+    public function setLastName($lastName)
+    {
+        $this->contactPerson['lastName'] = $lastName;
+        return $this;
+    }
+
+    /**
+     * @param string $email
+     *
+     * @return $this
+     */
+    public function setEmail($email)
+    {
+        $this->contactPerson['email'] = $email;
+        return $this;
+    }
+
+    /**
+     * @param string $externalId
+     *
+     * @return $this
+     */
+    public function setExternalId($externalId)
+    {
+        $this->contactPerson['externalId'] = $externalId;
+        return $this;
+    }
+
+    /**
+     * @param array $phones
+     *
+     * @return $this
+     */
+    public function setPhones($phones)
+    {
+        if (self::isPhonesArrayValid($phones)) {
+            $this->contactPerson['phones'] = $phones;
+        }
+
+        return $this;
+    }
+
+    /**
+     * @param array $address
+     *
+     * @return $this
+     */
+    public function setAddress($address)
+    {
+        if (is_array($address)) {
+            $this->contactPerson['address'] = $address;
+        }
+
+        return $this;
+    }
+
+    /**
+     * @param \WC_Customer $customer
+     *
+     * @return $this
+     */
+    public function setWcCustomer($customer)
+    {
+        if ($customer instanceof WC_Customer) {
+            $this->customer = $customer;
+        }
+
+        return $this;
+    }
+
+    /**
+     * Sets provided externalId and loads associated customer from DB (it it exists there).
+     * Returns true if everything went find; returns false if customer wasn't found.
+     *
+     * @param string $externalId
+     *
+     * @return bool
+     * @throws \Exception
+     */
+    public function loadExternalId($externalId)
+    {
+        try {
+            $wcCustomer = new WC_Customer($externalId);
+        } catch (\Exception $exception) {
+            return false;
+        }
+
+        $this->setExternalId($externalId);
+        $this->setWcCustomer($wcCustomer);
+
+        return true;
+    }
+
+    public function reset()
+    {
+        parent::reset();
+        $this->customer = new WC_Customer();
+        $this->contactPerson = array();
+        $this->customerBuilder = new WC_Retailcrm_WC_Customer_Builder();
+
+        return $this;
+    }
+
+    /**
+     * Fill WC_Customer fields with customer data from retailCRM.
+     * If field is not present in retailCRM customer - it will remain unchanged.
+     *
+     * @return $this|\WC_Retailcrm_Builder_Interface
+     */
+    public function build()
+    {
+        $this->checkBuilderValidity();
+        WC_Retailcrm_Logger::debug(
+            __METHOD__,
+            'Building WC_Customer from corporate data:',
+            $this->data,
+            "\nContact:",
+            $this->contactPerson
+        );
+
+       $wcCustomer = $this->customerBuilder
+           ->setData($this->contactPerson)
+           ->build()
+           ->getResult();
+
+        return $this;
+    }
+
+    /**
+     * @return mixed|\WC_Customer|null
+     */
+    public function getResult()
+    {
+        return $this->customer;
+    }
+
+    /**
+     * Throws an exception if internal state is not ready for data building.
+     *
+     * @throws \RuntimeException
+     */
+    private function checkBuilderValidity()
+    {
+        if (empty($this->data)) {
+            throw new \RuntimeException('Empty data');
+        }
+
+        if (!is_array($this->data)) {
+            throw new \RuntimeException('Data must be an array');
+        }
+    }
+
+    /**
+     * Returns true if provided variable contains array with customer phones.
+     *
+     * @param mixed $phones
+     *
+     * @return bool
+     */
+    private static function isPhonesArrayValid($phones)
+    {
+        if (!is_array($phones)) {
+            return false;
+        }
+
+        foreach ($phones as $phone) {
+            if (!is_array($phone) || count($phone) != 1 || !array_key_exists('number', $phone)) {
+                return false;
+            }
+        }
+
+        return true;
+    }
+}
diff --git a/src/include/interfaces/class-wc-retailcrm-builder-interface.php b/src/include/interfaces/class-wc-retailcrm-builder-interface.php
new file mode 100644
index 0000000..a493078
--- /dev/null
+++ b/src/include/interfaces/class-wc-retailcrm-builder-interface.php
@@ -0,0 +1,48 @@
+<?php
+
+/**
+ * Interface WC_Retailcrm_Builder_Interface.
+ * Main interface for builders. All builders
+ */
+interface WC_Retailcrm_Builder_Interface {
+    /**
+     * Sets data into builder
+     *
+     * @param array|mixed $data
+     *
+     * @return self
+     */
+    public function setData($data);
+
+    /**
+     * Returns data present in the builder
+     *
+     * @return array|mixed
+     */
+    public function getData();
+
+    /**
+     * This method should build result with data present in the builder.
+     * It should return builder instance in spite of actual building result.
+     * Any exception can be thrown in case of error. It should be processed accordingly.
+     *
+     * @return self
+     * @throws \Exception
+     */
+    public function build();
+
+    /**
+     * This method should reset builder state.
+     * In other words, after calling reset() builder inner state should become identical to newly created builder's state.
+     *
+     * @return self
+     */
+    public function reset();
+
+    /**
+     * Returns builder result. Can be anything (depends on builder).
+     *
+     * @return mixed|null
+     */
+    public function getResult();
+}
diff --git a/src/include/models/class-wc-retailcrm-customer-data-replacer-result.php b/src/include/models/class-wc-retailcrm-customer-data-replacer-result.php
new file mode 100644
index 0000000..60d9925
--- /dev/null
+++ b/src/include/models/class-wc-retailcrm-customer-data-replacer-result.php
@@ -0,0 +1,50 @@
+<?php
+
+/**
+ * Class WC_Retailcrm_Customer_Data_Replacer_Result
+ * Holds modified order and customer which was set in the order.
+ * If customer is null, then only order props was updated. Previous customer (if it was registered)
+ * will be detached from this order.
+ */
+class WC_Retailcrm_Customer_Data_Replacer_Result
+{
+    /** @var \WC_Customer|null */
+    private $wcCustomer;
+
+    /** @var \WC_Order $wcOrder */
+    private $wcOrder;
+
+    /**
+     * WC_Retailcrm_Customer_Data_Replacer_Result constructor.
+     *
+     * @param \WC_Customer|null $wcCustomer
+     * @param \WC_Order         $wcOrder
+     */
+    public function __construct($wcCustomer, $wcOrder)
+    {
+        $this->wcCustomer = $wcCustomer;
+        $this->wcOrder = $wcOrder;
+
+        if ((!is_null($this->wcCustomer) && !($this->wcCustomer instanceof WC_Customer))
+            || !($this->wcOrder instanceof WC_Order)
+        ) {
+            throw new \InvalidArgumentException(sprintf('Incorrect data provided to %s', __CLASS__));
+        }
+    }
+
+    /**
+     * @return \WC_Customer|null
+     */
+    public function getWcCustomer()
+    {
+        return $this->wcCustomer;
+    }
+
+    /**
+     * @return \WC_Order
+     */
+    public function getWcOrder()
+    {
+        return $this->wcOrder;
+    }
+}
diff --git a/src/include/models/class-wc-retailcrm-customer-data-replacer-state.php b/src/include/models/class-wc-retailcrm-customer-data-replacer-state.php
new file mode 100644
index 0000000..e7a0180
--- /dev/null
+++ b/src/include/models/class-wc-retailcrm-customer-data-replacer-state.php
@@ -0,0 +1,146 @@
+<?php
+
+/**
+ * Class WC_Retailcrm_Customer_Data_Replacer_State
+ * Holds WC_Retailcrm_Customer_Data_Replacer state. It exists only because we need to comply with builder interface.
+ */
+class WC_Retailcrm_Customer_Data_Replacer_State
+{
+    /** @var \WC_Order $wcOrder */
+   private $wcOrder;
+
+   /** @var array */
+   private $newCustomer;
+
+   /** @var array */
+   private $newContact;
+
+   /** @var array */
+   private $newCorporateCustomer;
+
+   /** @var array $newCompany */
+    private $newCompany;
+
+    /**
+     * @return \WC_Order
+     */
+    public function getWcOrder()
+    {
+        return $this->wcOrder;
+    }
+
+    /**
+     * @param \WC_Order $wcOrder
+     *
+     * @return WC_Retailcrm_Customer_Data_Replacer_State
+     */
+    public function setWcOrder($wcOrder)
+    {
+        $this->wcOrder = $wcOrder;
+        return $this;
+    }
+
+    /**
+     * @return array
+     */
+    public function getNewCustomer()
+    {
+        return $this->newCustomer;
+    }
+
+    /**
+     * @param array $newCustomer
+     *
+     * @return WC_Retailcrm_Customer_Data_Replacer_State
+     */
+    public function setNewCustomer($newCustomer)
+    {
+        $this->newCustomer = $newCustomer;
+        return $this;
+    }
+
+    /**
+     * @return array
+     */
+    public function getNewContact()
+    {
+        return $this->newContact;
+    }
+
+    /**
+     * @param array $newContact
+     *
+     * @return WC_Retailcrm_Customer_Data_Replacer_State
+     */
+    public function setNewContact($newContact)
+    {
+        $this->newContact = $newContact;
+        return $this;
+    }
+
+    /**
+     * @return array
+     */
+    public function getNewCorporateCustomer()
+    {
+        return $this->newCorporateCustomer;
+    }
+
+    /**
+     * @param array $newCorporateCustomer
+     *
+     * @return WC_Retailcrm_Customer_Data_Replacer_State
+     */
+    public function setNewCorporateCustomer($newCorporateCustomer)
+    {
+        $this->newCorporateCustomer = $newCorporateCustomer;
+        return $this;
+    }
+
+    /**
+     * @return array
+     */
+    public function getNewCompany()
+    {
+        return $this->newCompany;
+    }
+
+    /**
+     * @param array $newCompany
+     *
+     * @return WC_Retailcrm_Customer_Data_Replacer_State
+     */
+    public function setNewCompany($newCompany)
+    {
+        $this->newCompany = $newCompany;
+        return $this;
+    }
+
+    /**
+     * Throws an exception if state is not valid
+     *
+     * @throws \InvalidArgumentException
+     * @return void
+     */
+    public function validate()
+    {
+        if (empty($this->getWcOrder())) {
+            throw new \InvalidArgumentException('Empty WC_Order.');
+        }
+
+        if (empty($this->getNewCustomer())
+            && empty($this->getNewContact())
+            && empty($this->getNewCorporateCustomer())
+        ) {
+            throw new \InvalidArgumentException('New customer, new contact and new corporate customer is empty.');
+        }
+
+        if (!empty($this->getNewCustomer())
+            && (!empty($this->getNewContact()) || !empty($this->getNewCorporateCustomer()))
+        ) {
+            throw new \InvalidArgumentException(
+                'Too much data in state - cannot determine which customer should be used.'
+            );
+        }
+    }
+}
diff --git a/src/retailcrm.php b/src/retailcrm.php
index 8c1392f..e3247fb 100644
--- a/src/retailcrm.php
+++ b/src/retailcrm.php
@@ -41,10 +41,19 @@ if (!class_exists( 'WC_Integration_Retailcrm')) :
             $this->load_plugin_textdomain();
 
             if (class_exists( 'WC_Integration' )) {
-                require_once(dirname(__FILE__ ) . '/include/class-wc-retailcrm-logger.php');
+                require_once(dirname(__FILE__) . '/include/interfaces/class-wc-retailcrm-builder-interface.php');
+                require_once(dirname(__FILE__ ) . '/include/models/class-wc-retailcrm-customer-data-replacer-state.php');
+                require_once(dirname(__FILE__ ) . '/include/models/class-wc-retailcrm-customer-data-replacer-result.php');
+                require_once(dirname(__FILE__ ) . '/include/components/class-wc-retailcrm-logger.php');
+                require_once(dirname(__FILE__ ) . '/include/components/class-wc-retailcrm-history-assembler.php');
+                require_once(dirname(__FILE__ ) . '/include/components/class-wc-retailcrm-paginated-request.php');
+                require_once(dirname(__FILE__ ) . '/include/components/class-wc-retailcrm-customer-data-replacer.php');
+                require_once(dirname(__FILE__ ) . '/include/components/class-wc-retailcrm-customer-data-replacer.php');
+                require_once(dirname(__FILE__ ) . '/include/abstracts/class-wc-retailcrm-abstract-builder.php');
                 require_once(dirname(__FILE__ ) . '/include/abstracts/class-wc-retailcrm-abstracts-settings.php');
                 require_once(dirname(__FILE__ ) . '/include/abstracts/class-wc-retailcrm-abstracts-data.php');
                 require_once(dirname(__FILE__ ) . '/include/abstracts/class-wc-retailcrm-abstracts-address.php');
+                require_once(dirname(__FILE__ ) . '/include/customer/woocommerce/class-wc-retailcrm-wc-customer-builder.php');
                 require_once(dirname(__FILE__ ) . '/include/order/class-wc-retailcrm-order.php');
                 require_once(dirname(__FILE__ ) . '/include/order/class-wc-retailcrm-order-payment.php');
                 require_once(dirname(__FILE__ ) . '/include/order/class-wc-retailcrm-order-item.php');