diff --git a/README.md b/README.md
index db29aa9..49e6a76 100644
--- a/README.md
+++ b/README.md
@@ -25,8 +25,8 @@ You can find function references in the [client folder](https://github.com/omnis
 
 Before using Omnisend Client you need to ensure the following conditions:
 * Omnisend Plugin is installed `is_plugin_active( 'omnisend/class-omnisend-core-bootstrap.php' )`
-* Omnisend Plugin is up to date   `class_exists( 'Omnisend\Public\V1\Omnisend' )`
-* Omnisend is connected to the WordPress  `Omnisend\Public\V1\Omnisend::is_connected()`
+* Omnisend Plugin is up to date `class_exists( 'Omnisend\SDK\V1\Omnisend' )`
+* Omnisend is connected to account `Omnisend\SDK\V1\Omnisend::is_connected()`
 
 If any of these conditions are false you should ask to resolve them.
 
@@ -36,7 +36,7 @@ To send contact to the Omnisend you need to provide your integration name & vers
 
 This is done by getting an actual client
 
-` $client = \Omnisend\Public\V1\Omnisend::get_client( 'integration name', 'integration version' );`
+` $client = \Omnisend\SDK\V1\Omnisend::get_client( 'integration name', 'integration version' );`
 
 'integration name' - should be your integration name
 'integration version' - should be your integration version
@@ -64,7 +64,7 @@ Here is how you can create a basic client & submit contact.
 			$contact->set_email_opt_in( 'where user opted to become subscriber' );
 		}
 
-        $client = \Omnisend\Public\V1\Omnisend::get_client( 'integration name', 'integration version' );
+        $client = \Omnisend\SDK\V1\Omnisend::get_client( 'integration name', 'integration version' );
                     
         $response = $client->create_contact( $contact );
 ```
@@ -74,15 +74,15 @@ Here is how you can create a basic client & submit contact.
 If data provided is invalid or creation fails, then
 
 ```php
-$client->create_contact($contact)
+$response = $client->create_contact($contact)
 ```
 
-Will return `errors` in `WP_Error`. Depending on your integration logic you should handle the error i.e
+Will return `CreateContactResponse`. Depending on your integration logic you should handle the error i.e
 
 ```php
-	if ( is_wp_error( $response ) ) {
-		error_log( 'Error in after_submission: ' . $response->get_error_message());
-		return;
+    if ( $response->get_wp_error()->has_errors() ) {
+        error_log( 'Error in after_submission: ' . $response->get_wp_error()->get_error_message());
+        return;
     }
 ```
 
diff --git a/omnisend/class-omnisend-core-bootstrap.php b/omnisend/class-omnisend-core-bootstrap.php
index 44d50ea..eb97a4e 100644
--- a/omnisend/class-omnisend-core-bootstrap.php
+++ b/omnisend/class-omnisend-core-bootstrap.php
@@ -4,7 +4,7 @@
  *
  * Plugin Name: Omnisend
  * Description: Omnisend main plugin that enables integration with Omnisend.
- * Version: 1.1.4
+ * Version: 1.2.0
  * Author: Omnisend
  * Author URI: https://www.omnisend.com
  * Developer: Omnisend
@@ -22,7 +22,7 @@
 
 defined( 'ABSPATH' ) || die( 'no direct access' );
 
-const OMNISEND_CORE_PLUGIN_VERSION = '1.1.4';
+const OMNISEND_CORE_PLUGIN_VERSION = '1.2.0';
 const OMNISEND_CORE_SETTINGS_PAGE  = 'omnisend';
 const OMNISEND_CORE_PLUGIN_NAME    = 'Email Marketing by Omnisend';
 
@@ -71,13 +71,13 @@ public static function load_omnisend_admin_styles(): void {
 					'roboto.css',
 					plugin_dir_url( __FILE__ ) . 'assets/fonts/roboto/roboto.css?' . time(),
 					array(),
-					'1.1.4',
+					OMNISEND_CORE_PLUGIN_VERSION,
 				);
 				wp_enqueue_style(
 					'styles.css',
 					plugin_dir_url( __FILE__ ) . 'styles/styles.css?' . time(),
 					array(),
-					'1.1.4',
+					OMNISEND_CORE_PLUGIN_VERSION,
 				);
 			}
 		}
diff --git a/omnisend/includes/Internal/V1/class-client.php b/omnisend/includes/Internal/V1/class-client.php
index 4f70bbf..a3b9833 100644
--- a/omnisend/includes/Internal/V1/class-client.php
+++ b/omnisend/includes/Internal/V1/class-client.php
@@ -7,12 +7,13 @@
 
 namespace Omnisend\Internal\V1;
 
-use Omnisend\Public\V1\Contact;
+use Omnisend\SDK\V1\Contact;
+use Omnisend\SDK\V1\CreateContactResponse;
 use WP_Error;
 
 defined( 'ABSPATH' ) || die( 'no direct access' );
 
-class Client implements \Omnisend\Public\V1\Client {
+class Client implements \Omnisend\SDK\V1\Client {
 
 	private string $api_key;
 	private string $plugin_name;
@@ -30,19 +31,19 @@ public function __construct( string $api_key, string $plugin_name, string $plugi
 	}
 
 
-	public function create_contact( $contact ): mixed {
+	public function create_contact( $contact ): CreateContactResponse {
 		$error = new WP_Error();
 
 		if ( $contact instanceof Contact ) {
 			$error->merge_from( $contact->validate() );
 		} else {
-			$error->add( 'contact', 'Contact is not instance of Omnisend\Public\V1\Contact.' );
+			$error->add( 'contact', 'Contact is not instance of Omnisend\SDK\V1\Contact.' );
 		}
 
 		$error->merge_from( $this->check_setup() );
 
 		if ( $error->has_errors() ) {
-			return $error;
+			return new CreateContactResponse( '', $error );
 		}
 
 		$response = wp_remote_post(
@@ -61,7 +62,7 @@ public function create_contact( $contact ): mixed {
 
 		if ( is_wp_error( $response ) ) {
 			error_log('wp_remote_post error: ' . $response->get_error_message()); // phpcs:ignore
-			return $response;
+			return new CreateContactResponse( '', $response );
 		}
 
 		$http_code = wp_remote_retrieve_response_code( $response );
@@ -69,23 +70,23 @@ public function create_contact( $contact ): mixed {
 			$body    = wp_remote_retrieve_body( $response );
 			$err_msg = "HTTP error: {$http_code} - " . wp_remote_retrieve_response_message( $response ) . " - {$body}";
 			$error->add( 'omnisend_api', $err_msg );
-			return $error;
+			return new CreateContactResponse( '', $error );
 		}
 
 		$body = wp_remote_retrieve_body( $response );
 		if ( ! $body ) {
 			$error->add( 'omnisend_api', 'empty response' );
-			return $error;
+			return new CreateContactResponse( '', $error );
 		}
 
 		$arr = json_decode( $body, true );
 
 		if ( empty( $arr['contactID'] ) ) {
 			$error->add( 'omnisend_api', 'contactID not found in response.' );
-			return $error;
+			return new CreateContactResponse( '', $error );
 		}
 
-		return (string) $arr['contactID'];
+		return new CreateContactResponse( (string) $arr['contactID'], $error );
 	}
 
 	/**
diff --git a/omnisend/includes/Internal/class-connection.php b/omnisend/includes/Internal/class-connection.php
index 35641eb..0e43b4c 100644
--- a/omnisend/includes/Internal/class-connection.php
+++ b/omnisend/includes/Internal/class-connection.php
@@ -30,7 +30,7 @@ public static function display(): void {
 				return;
 			}
 
-			if ( $response['verified'] === true && $response['platform'] !== wordpress_platform ) {
+			if ( $response['verified'] === true && $response['platform'] !== $wordpress_platform ) {
 				echo '<div class="notice notice-error"><p>This Omnisend account is already connected to non-WordPress site. Log in to access it.
 				<a target="_blank" href="https://www.omnisend.com/customer-support/">Contact our support</a> if you have other issues.</p></div>';
 				require_once __DIR__ . '/../../view/connection-form.html';
@@ -38,7 +38,7 @@ public static function display(): void {
 			}
 
 			$connected = false;
-			if ( $response['platform'] === wordpress_platform ) {
+			if ( $response['platform'] === $wordpress_platform ) {
 				$connected = true;
 			}
 
diff --git a/omnisend/includes/Public/V1/class-client.php b/omnisend/includes/SDK/V1/class-client.php
similarity index 69%
rename from omnisend/includes/Public/V1/class-client.php
rename to omnisend/includes/SDK/V1/class-client.php
index 411d841..9a0cd88 100644
--- a/omnisend/includes/Public/V1/class-client.php
+++ b/omnisend/includes/SDK/V1/class-client.php
@@ -5,7 +5,7 @@
  * @package OmnisendClient
  */
 
-namespace Omnisend\Public\V1;
+namespace Omnisend\SDK\V1;
 
 use WP_Error;
 
@@ -22,7 +22,7 @@ interface Client {
 	 *
 	 * @param Contact $contact
 	 *
-	 * @return string|WP_Error Created/updated contact identifier (ID) or WP_Error
+	 * @return CreateContactResponse
 	 */
-	public function create_contact( $contact ): mixed;
+	public function create_contact( $contact ): CreateContactResponse;
 }
diff --git a/omnisend/includes/Public/V1/class-contact.php b/omnisend/includes/SDK/V1/class-contact.php
similarity index 99%
rename from omnisend/includes/Public/V1/class-contact.php
rename to omnisend/includes/SDK/V1/class-contact.php
index bb69b7e..1e6d4aa 100644
--- a/omnisend/includes/Public/V1/class-contact.php
+++ b/omnisend/includes/SDK/V1/class-contact.php
@@ -5,7 +5,7 @@
  * @package OmnisendClient
  */
 
-namespace Omnisend\Public\V1;
+namespace Omnisend\SDK\V1;
 
 use Omnisend\Internal\Utils;
 use WP_Error;
diff --git a/omnisend/includes/SDK/V1/class-createcontactresponse.php b/omnisend/includes/SDK/V1/class-createcontactresponse.php
new file mode 100644
index 0000000..e61a332
--- /dev/null
+++ b/omnisend/includes/SDK/V1/class-createcontactresponse.php
@@ -0,0 +1,36 @@
+<?php
+/**
+ * Omnisend Client
+ *
+ * @package OmnisendClient
+ */
+
+namespace Omnisend\SDK\V1;
+
+use WP_Error;
+
+defined( 'ABSPATH' ) || die( 'no direct access' );
+
+class CreateContactResponse {
+
+	private string $contact_id;
+
+	private WP_Error $wp_error;
+
+	/**
+	 * @param string $contact_id
+	 * @param WP_Error $wp_error
+	 */
+	public function __construct( string $contact_id, WP_Error $wp_error ) {
+		$this->contact_id = $contact_id;
+		$this->wp_error   = $wp_error;
+	}
+
+	public function get_contact_id(): string {
+		return $this->contact_id;
+	}
+
+	public function get_wp_error(): WP_Error {
+		return $this->wp_error;
+	}
+}
diff --git a/omnisend/includes/Public/V1/class-omnisend.php b/omnisend/includes/SDK/V1/class-omnisend.php
similarity index 96%
rename from omnisend/includes/Public/V1/class-omnisend.php
rename to omnisend/includes/SDK/V1/class-omnisend.php
index 148e070..8f04b78 100644
--- a/omnisend/includes/Public/V1/class-omnisend.php
+++ b/omnisend/includes/SDK/V1/class-omnisend.php
@@ -5,7 +5,7 @@
  * @package OmnisendClient
  */
 
-namespace Omnisend\Public\V1;
+namespace Omnisend\SDK\V1;
 
 use Omnisend\Internal\Options;
 
diff --git a/omnisend/readme.txt b/omnisend/readme.txt
index 3f826cb..41e59b4 100644
--- a/omnisend/readme.txt
+++ b/omnisend/readme.txt
@@ -5,7 +5,7 @@ Tags: email marketing, marketing, newsletter, sms, form
 Requires at least: 4.7.0
 Tested up to: 6.4
 Requires PHP: 7.1
-Stable tag: 1.1.4
+Stable tag: 1.2.0
 License: GPLv3 or later
 URI: http://www.gnu.org/licenses/gpl-3.0.html
 
@@ -54,6 +54,10 @@ Read Omnisend [Terms of Use](https://www.omnisend.com/terms)
 
 == Changelog ==
 
+= 1.2.0 =
+
+* Improve SDK client
+
 = 1.1.4 =
 
 * Improve connection messages