diff --git a/v5/client.go b/v5/client.go
index 69aac2f..ec371f6 100644
--- a/v5/client.go
+++ b/v5/client.go
@@ -1,20 +1,20 @@
 package v5
 
 import (
+	"encoding/json"
 	"errors"
 	"fmt"
-	"encoding/json"
+	"github.com/google/go-querystring/query"
 	"io/ioutil"
 	"net/http"
 	"net/url"
-	"strings"
 	"strconv"
+	"strings"
 	"time"
-	"github.com/google/go-querystring/query"
 )
 
 const (
-	versionedPrefix = "/api/v5"
+	versionedPrefix   = "/api/v5"
 	unversionedPrefix = "/api"
 )
 
@@ -43,7 +43,7 @@ func New(url string, key string) *Client {
 func (c *Client) getRequest(urlWithParameters string) ([]byte, int, error) {
 	var res []byte
 
-	req, err := http.NewRequest("GET", fmt.Sprintf("%s%s", c.Url , urlWithParameters), nil)
+	req, err := http.NewRequest("GET", fmt.Sprintf("%s%s", c.Url, urlWithParameters), nil)
 	if err != nil {
 		return res, 0, err
 	}
@@ -119,7 +119,7 @@ func (c *Client) ErrorResponse(data []byte) (*ErrorResponse, error) {
 }
 
 // checkBy select identifier type
-func checkBy(by string) string  {
+func checkBy(by string) string {
 	var context = "id"
 
 	if by != "id" {
@@ -133,15 +133,10 @@ func checkBy(by string) string  {
 func (c *Client) ApiVersions() (*VersionResponse, int, error) {
 	var resp VersionResponse
 	data, status, err := c.getRequest(fmt.Sprintf("%s/api-versions", unversionedPrefix))
-
 	if err != nil {
 		return &resp, status, err
 	}
 
-	if status >= http.StatusBadRequest {
-		return &resp, status, errors.New(fmt.Sprintf("HTTP request error. Status code: %d.\n", status))
-	}
-
 	err = json.Unmarshal(data, &resp)
 
 	return &resp, status, err
@@ -151,15 +146,10 @@ func (c *Client) ApiVersions() (*VersionResponse, int, error) {
 func (c *Client) ApiCredentials() (*CredentialResponse, int, error) {
 	var resp CredentialResponse
 	data, status, err := c.getRequest(fmt.Sprintf("%s/credentials", unversionedPrefix))
-
 	if err != nil {
 		return &resp, status, err
 	}
 
-	if status >= http.StatusBadRequest {
-		return &resp, status, errors.New(fmt.Sprintf("HTTP request error. Status code: %d.\n", status))
-	}
-
 	err = json.Unmarshal(data, &resp)
 
 	return &resp, status, err
@@ -177,10 +167,6 @@ func (c *Client) Customer(id, by, site string) (*CustomerResponse, int, error) {
 		return &resp, status, err
 	}
 
-	if status >= http.StatusBadRequest {
-		return &resp, status, errors.New(fmt.Sprintf("HTTP request error. Status code: %d.\n", status))
-	}
-
 	err = json.Unmarshal(data, &resp)
 
 	return &resp, status, err
@@ -202,21 +188,16 @@ func (c *Client) Customers(filter CustomersFilter, limit, page int) (*CustomersR
 	params, _ := query.Values(fw)
 
 	data, status, err := c.getRequest(fmt.Sprintf("%s/customers?%s", versionedPrefix, params.Encode()))
-
 	if err != nil {
 		return &resp, status, err
 	}
 
-	if status >= http.StatusBadRequest {
-		return &resp, status, errors.New(fmt.Sprintf("HTTP request error. Status code: %d.\n", status))
-	}
-
 	err = json.Unmarshal(data, &resp)
 
 	return &resp, status, err
 }
 
-func (c *Client) CustomerCreate(customer Customer, site ...string) (*CustomerChangeResponse, int, error)  {
+func (c *Client) CustomerCreate(customer Customer, site ...string) (*CustomerChangeResponse, int, error) {
 	var resp CustomerChangeResponse
 	customerJson, _ := json.Marshal(&customer)
 
@@ -233,22 +214,16 @@ func (c *Client) CustomerCreate(customer Customer, site ...string) (*CustomerCha
 	}
 
 	data, status, err := c.postRequest(fmt.Sprintf("%s/customers/create", versionedPrefix), p)
-
-
 	if err != nil {
 		return &resp, status, err
 	}
 
-	if status >= http.StatusBadRequest {
-		return &resp, status, errors.New(fmt.Sprintf("HTTP request error. Status code: %d.\n", status))
-	}
-
 	err = json.Unmarshal(data, &resp)
 
 	return &resp, status, err
 }
 
-func (c *Client) CustomerEdit(customer Customer, by string, site ...string) (*CustomerChangeResponse, int, error)  {
+func (c *Client) CustomerEdit(customer Customer, by string, site ...string) (*CustomerChangeResponse, int, error) {
 	var resp CustomerChangeResponse
 	var uid = strconv.Itoa(customer.Id)
 	var context = checkBy(by)
@@ -260,7 +235,7 @@ func (c *Client) CustomerEdit(customer Customer, by string, site ...string) (*Cu
 	customerJson, _ := json.Marshal(&customer)
 
 	p := url.Values{
-		"by": {string(context)},
+		"by":       {string(context)},
 		"customer": {string(customerJson[:])},
 	}
 
@@ -277,11 +252,11 @@ func (c *Client) CustomerEdit(customer Customer, by string, site ...string) (*Cu
 		return &resp, status, err
 	}
 
-	if status >= http.StatusBadRequest {
-		return &resp, status, errors.New(fmt.Sprintf("HTTP request error. Status code: %d.\n", status))
-	}
-
 	err = json.Unmarshal(data, &resp)
 
 	return &resp, status, err
 }
+
+func (c *Client) CustomersUpload() {
+
+}
diff --git a/v5/client_test.go b/v5/client_test.go
index ee27c14..c16a600 100644
--- a/v5/client_test.go
+++ b/v5/client_test.go
@@ -1,14 +1,14 @@
 package v5
 
 import (
+	"encoding/json"
 	"fmt"
-	"time"
-	"os"
-	"testing"
+	"math/rand"
 	"net/http"
 	"net/url"
-	"encoding/json"
-	"math/rand"
+	"os"
+	"testing"
+	"time"
 )
 
 type Configuration struct {
@@ -26,7 +26,7 @@ func buildConfiguration() *Configuration {
 		fmt.Println("error:", err)
 	}
 
-	return &Configuration {
+	return &Configuration{
 		configuration.Url,
 		configuration.Key,
 		configuration.Ver,
@@ -42,9 +42,11 @@ func init() {
 func RandomString(strlen int) string {
 	const chars = "abcdefghijklmnopqrstuvwxyz0123456789"
 	result := make([]byte, strlen)
+
 	for i := range result {
 		result[i] = chars[r.Intn(len(chars))]
 	}
+
 	return string(result)
 }
 
@@ -55,7 +57,6 @@ func client() *Client {
 
 func TestGetRequest(t *testing.T) {
 	c := client()
-
 	_, status, _ := c.getRequest("/fake-method")
 
 	if status != http.StatusNotFound {
@@ -65,7 +66,6 @@ func TestGetRequest(t *testing.T) {
 
 func TestPostRequest(t *testing.T) {
 	c := client()
-
 	_, status, _ := c.postRequest("/fake-method", url.Values{})
 
 	if status != http.StatusNotFound {
@@ -75,9 +75,7 @@ func TestPostRequest(t *testing.T) {
 
 func TestClient_ApiVersionsVersions(t *testing.T) {
 	c := client()
-
 	data, status, err := c.ApiVersions()
-
 	if err != nil {
 		t.Fail()
 	}
@@ -93,9 +91,7 @@ func TestClient_ApiVersionsVersions(t *testing.T) {
 
 func TestClient_ApiCredentialsCredentials(t *testing.T) {
 	c := client()
-
 	data, status, err := c.ApiCredentials()
-
 	if err != nil {
 		t.Fail()
 	}
@@ -115,7 +111,6 @@ func TestClient_CustomersCustomers(t *testing.T) {
 	f.City = "Москва"
 
 	data, status, err := c.Customers(f, 20, 1)
-
 	if err != nil {
 		t.Errorf("%s", err)
 		t.Fail()
@@ -132,8 +127,6 @@ func TestClient_CustomersCustomers(t *testing.T) {
 	}
 }
 
-
-
 func TestClient_CustomerChange(t *testing.T) {
 	c := client()
 	f := Customer{}
@@ -147,7 +140,6 @@ func TestClient_CustomerChange(t *testing.T) {
 	f.Email = fmt.Sprintf("%s@example.com", random)
 
 	cr, sc, err := c.CustomerCreate(f)
-
 	if err != nil {
 		t.Errorf("%s", err)
 		t.Fail()
@@ -167,7 +159,6 @@ func TestClient_CustomerChange(t *testing.T) {
 	f.Vip = true
 
 	ed, se, err := c.CustomerEdit(f, "id")
-
 	if err != nil {
 		t.Errorf("%s", err)
 		t.Fail()
@@ -184,7 +175,6 @@ func TestClient_CustomerChange(t *testing.T) {
 	}
 
 	data, status, err := c.Customer(f.ExternalId, "externalId", "")
-
 	if err != nil {
 		t.Errorf("%s", err)
 		t.Fail()