diff --git a/mailpoet/lib/API/JSON/v1/Settings.php b/mailpoet/lib/API/JSON/v1/Settings.php
index c2cd83a613..50776102f0 100644
--- a/mailpoet/lib/API/JSON/v1/Settings.php
+++ b/mailpoet/lib/API/JSON/v1/Settings.php
@@ -4,7 +4,9 @@ namespace MailPoet\API\JSON\v1;
 
 use MailPoet\API\JSON\Endpoint as APIEndpoint;
 use MailPoet\API\JSON\Error as APIError;
+use MailPoet\API\JSON\ErrorResponse;
 use MailPoet\API\JSON\Response;
+use MailPoet\API\JSON\SuccessResponse;
 use MailPoet\Config\AccessControl;
 use MailPoet\Config\ServicesChecker;
 use MailPoet\Cron\Workers\SubscribersEngagementScore;
@@ -493,4 +495,24 @@ class Settings extends APIEndpoint {
       'action' => 'reactivate',
     ];
   }
+
+  /**
+   * Prepares the settings to set up MSS with the given key and calls the set method.
+   *
+   * @param string $apiKey
+   * @return ErrorResponse|SuccessResponse
+   */
+  public function setupMSS(string $apiKey) {
+    $new_settings = [
+      'mta_group' => 'mailpoet',
+      'mta' => [
+        'method' => 'MailPoet',
+        'mailpoet_api_key' => $apiKey,
+      ],
+      'signup_confirmation' => [
+        'enabled' => '1',
+      ],
+    ];
+    return $this->set($new_settings);
+  }
 }
diff --git a/mailpoet/lib/Config/Hooks.php b/mailpoet/lib/Config/Hooks.php
index bb79d48872..f7003a062c 100644
--- a/mailpoet/lib/Config/Hooks.php
+++ b/mailpoet/lib/Config/Hooks.php
@@ -13,6 +13,7 @@ use MailPoet\Subscription\Form;
 use MailPoet\Subscription\Manage;
 use MailPoet\Subscription\Registration;
 use MailPoet\WP\Functions as WPFunctions;
+use MailPoet\WPCOM\DotcomLicenseProvisioner;
 
 class Hooks {
   /** @var Form */
@@ -54,6 +55,9 @@ class Hooks {
   /** @var SubscriberChangesNotifier */
   private $subscriberChangesNotifier;
 
+  /** @var DotcomLicenseProvisioner */
+  private $dotcomLicenseProvisioner;
+
   public function __construct(
     Form $subscriptionForm,
     Comment $subscriptionComment,
@@ -67,7 +71,8 @@ class Hooks {
     HooksWooCommerce $hooksWooCommerce,
     SubscriberHandler $subscriberHandler,
     SubscriberChangesNotifier $subscriberChangesNotifier,
-    WP $wpSegment
+    WP $wpSegment,
+    DotcomLicenseProvisioner $dotcomLicenseProvisioner
   ) {
     $this->subscriptionForm = $subscriptionForm;
     $this->subscriptionComment = $subscriptionComment;
@@ -82,6 +87,7 @@ class Hooks {
     $this->subscriberHandler = $subscriberHandler;
     $this->hooksWooCommerce = $hooksWooCommerce;
     $this->subscriberChangesNotifier = $subscriberChangesNotifier;
+    $this->dotcomLicenseProvisioner = $dotcomLicenseProvisioner;
   }
 
   public function init() {
@@ -99,6 +105,7 @@ class Hooks {
     $this->setupFooter();
     $this->setupSettingsLinkInPluginPage();
     $this->setupChangeNotifications();
+    $this->setupLicenseProvisioning();
   }
 
   public function initEarlyHooks() {
@@ -475,4 +482,13 @@ class Hooks {
       [$this->subscriberChangesNotifier, 'notify']
     );
   }
+
+  public function setupLicenseProvisioning(): void {
+    $this->wp->addFilter(
+      'wpcom_marketplace_webhook_response_mailpoet-business',
+      [$this->dotcomLicenseProvisioner, 'provisionLicense'],
+      10,
+      3
+    );
+  }
 }
diff --git a/mailpoet/lib/DI/ContainerConfigurator.php b/mailpoet/lib/DI/ContainerConfigurator.php
index 101db072f8..fe2407bfbc 100644
--- a/mailpoet/lib/DI/ContainerConfigurator.php
+++ b/mailpoet/lib/DI/ContainerConfigurator.php
@@ -537,6 +537,8 @@ class ContainerConfigurator implements IContainerConfigurator {
     $container->autowire(\MailPoet\WP\Emoji::class)->setPublic(true);
     $container->autowire(\MailPoet\WP\Functions::class)->setPublic(true);
     $container->autowire(\MailPoet\WP\AutocompletePostListLoader::class)->setPublic(true);
+    // WordPress.com
+    $container->autowire(\MailPoet\WPCOM\DotcomLicenseProvisioner::class)->setPublic(true);
     // Third party classes
     $container->autowire(\MailPoetVendor\CSS::class)->setClass(\MailPoetVendor\CSS::class)->setPublic(true);
     $container->autowire(\MailPoetVendor\csstidy::class)->setClass(\MailPoetVendor\csstidy::class);
diff --git a/mailpoet/lib/Logging/LoggerFactory.php b/mailpoet/lib/Logging/LoggerFactory.php
index 49db366de1..45a6853368 100644
--- a/mailpoet/lib/Logging/LoggerFactory.php
+++ b/mailpoet/lib/Logging/LoggerFactory.php
@@ -35,6 +35,7 @@ class LoggerFactory {
   const TOPIC_API = 'api';
   const TOPIC_TRACKING = 'tracking';
   const TOPIC_COUPONS = 'coupons';
+  const TOPIC_PROVISIONING = 'provisioning';
 
   /** @var LoggerFactory */
   private static $instance;
diff --git a/mailpoet/lib/WPCOM/DotcomLicenseProvisioner.php b/mailpoet/lib/WPCOM/DotcomLicenseProvisioner.php
new file mode 100644
index 0000000000..3e78cf2946
--- /dev/null
+++ b/mailpoet/lib/WPCOM/DotcomLicenseProvisioner.php
@@ -0,0 +1,126 @@
+<?php declare(strict_types = 1);
+
+namespace MailPoet\WPCOM;
+
+use MailPoet\API\JSON\ErrorResponse;
+use MailPoet\API\JSON\v1\Services;
+use MailPoet\API\JSON\v1\Settings;
+use MailPoet\Logging\LoggerFactory;
+use WP_Error;
+
+/**
+ * This class is responsible for receiving and activating the license purchased from WP.com Marketplace.
+ */
+class DotcomLicenseProvisioner {
+  const EVENT_TYPE_PROVISION_LICENSE = 'provision_license';
+
+  /** @var LoggerFactory */
+  private $loggerFactory;
+
+  /** @var Settings */
+  private $settings;
+
+  /** @var Services */
+  private $services;
+
+  public function __construct(
+    LoggerFactory $loggerFactory,
+    Settings $settings,
+    Services $services
+  ) {
+    $this->loggerFactory = $loggerFactory;
+    $this->settings = $settings;
+    $this->services = $services;
+  }
+
+  /**
+   * Returns true if in the context of WordPress.com Atomic platform.
+   *
+   * @return bool
+   */
+  private function isAtomicPlatform(): bool {
+    return defined('IS_ATOMIC') && IS_ATOMIC && defined('ATOMIC_CLIENT_ID') && (ATOMIC_CLIENT_ID === '2');
+  }
+
+  /**
+   * Activates MSS and adds API key for subscriptions purchased from WP.com Marketplace.
+   *
+   * @param bool $result
+   * @param array $licensePayload
+   * @param string $eventType
+   * @return bool|WP_Error
+   */
+  public function provisionLicense(bool $result, array $licensePayload, string $eventType) {
+    if (!$this->isAtomicPlatform() || $eventType !== self::EVENT_TYPE_PROVISION_LICENSE) {
+      return $result;
+    }
+
+    $apiKey = $this->getKeyFromPayload($licensePayload);
+    if (is_wp_error($apiKey)) {
+      $this->loggerFactory->getLogger(LoggerFactory::TOPIC_PROVISIONING)->error(
+        'key was not found in license payload');
+      return $apiKey;
+    }
+
+    return $this->activateMSS($apiKey);
+  }
+
+  /**
+   * Returns API key from license payload.
+   * @param array $licensePayload
+   * @return string|WP_Error
+   */
+  private function getKeyFromPayload(array $licensePayload) {
+    if (isset($licensePayload['apiKey']) && is_string($licensePayload['apiKey'])) {
+      return $licensePayload['apiKey'];
+    }
+
+    return new WP_Error('invalid_license_payload', 'Invalid license payload: Missing API key.');
+  }
+
+  /**
+   * Saves the API key and activates MSS.
+   * @param string $apiKey
+   * @return true|WP_Error
+   */
+  private function activateMSS(string $apiKey) {
+    $response = $this->settings->setupMSS($apiKey);
+    if ($response instanceof ErrorResponse) {
+      $this->loggerFactory->getLogger(LoggerFactory::TOPIC_PROVISIONING)->error(
+        'Setting sending method and key failed',
+        ['$response' => $response]
+      );
+      return new WP_Error('Provisioning failed setting the data', $this->concatMessages($response));
+    }
+
+    // This is necessary if the key changed but the sending method was already set to MailPoet
+    $response = $this->services->refreshMSSKeyStatus();
+    if ($response instanceof ErrorResponse) {
+      $this->loggerFactory->getLogger(LoggerFactory::TOPIC_PROVISIONING)->error(
+        'Refreshing the key failed',
+        ['$response' => $response]
+      );
+      return new WP_Error('Provisioning failed activating the data', $this->concatMessages($response));
+    }
+
+
+    $this->loggerFactory->getLogger(LoggerFactory::TOPIC_PROVISIONING)->info(
+      'License was provisioned'
+    );
+    return true;
+  }
+
+  private function concatMessages(ErrorResponse $response): string {
+    $data = $response->getData();
+    $result = '';
+
+    if (empty($data) || !isset($data['errors'])) {
+      return $result;
+    }
+
+    foreach ($data['errors'] as $error) {
+      $result .= $error['message'] . " ";
+    }
+    return $result;
+  }
+}