diff --git a/app/code/Magento/Sales/Model/Order/CustomerAssignment.php b/app/code/Magento/Sales/Model/Order/CustomerAssignment.php
new file mode 100644
index 0000000000000..b6ae86461c398
--- /dev/null
+++ b/app/code/Magento/Sales/Model/Order/CustomerAssignment.php
@@ -0,0 +1,58 @@
+<?php
+/**
+ * Copyright © Magento, Inc. All rights reserved.
+ * See COPYING.txt for license details.
+ */
+declare(strict_types=1);
+
+namespace Magento\Sales\Model\Order;
+
+use Magento\Sales\Api\Data\OrderInterface;
+use Magento\Sales\Api\OrderRepositoryInterface;
+use Magento\Customer\Api\Data\CustomerInterface;
+use Magento\Framework\Event\ManagerInterface;
+
+class CustomerAssignment
+{
+    /**
+     * @var ManagerInterface
+     */
+    private $eventManager;
+
+    /**
+     * @var OrderRepositoryInterface
+     */
+    private $orderRepository;
+
+    /**
+     * CustomerAssignment constructor.
+     *
+     * @param ManagerInterface $eventManager
+     * @param OrderRepositoryInterface $orderRepository
+     */
+    public function __construct(
+        ManagerInterface $eventManager,
+        OrderRepositoryInterface $orderRepository
+    ) {
+        $this->eventManager = $eventManager;
+        $this->orderRepository = $orderRepository;
+    }
+
+    /**
+     * @param OrderInterface $order
+     * @param CustomerInterface $customer
+     */
+    public function execute(OrderInterface $order, CustomerInterface $customer)/*: void*/
+    {
+        $order->setCustomerId($customer->getId());
+        $order->setCustomerIsGuest(false);
+        $this->orderRepository->save($order);
+
+        $this->eventManager->dispatch(
+            'sales_order_customer_assign_after', [
+                'order'     => $order,
+                'customer'  => $customer
+            ]
+        );
+    }
+}
diff --git a/app/code/Magento/Sales/Observer/AssignOrderToCustomerObserver.php b/app/code/Magento/Sales/Observer/AssignOrderToCustomerObserver.php
index f41ea6888264f..aba7d551d5330 100644
--- a/app/code/Magento/Sales/Observer/AssignOrderToCustomerObserver.php
+++ b/app/code/Magento/Sales/Observer/AssignOrderToCustomerObserver.php
@@ -12,6 +12,7 @@
 use Magento\Framework\Event\Observer;
 use Magento\Framework\Event\ObserverInterface;
 use Magento\Sales\Api\OrderRepositoryInterface;
+use Magento\Sales\Model\Order\CustomerAssignment;
 
 /**
  * Assign order to customer created after issuing guest order.
@@ -24,11 +25,22 @@ class AssignOrderToCustomerObserver implements ObserverInterface
     private $orderRepository;
 
     /**
+     * @var CustomerAssignment
+     */
+    private $customerAssignmentService;
+
+    /**
+     * AssignOrderToCustomerObserver constructor.
+     *
      * @param OrderRepositoryInterface $orderRepository
+     * @param CustomerAssignment $customerAssignmentService
      */
-    public function __construct(OrderRepositoryInterface $orderRepository)
-    {
+    public function __construct(
+        OrderRepositoryInterface $orderRepository,
+        CustomerAssignment $customerAssignmentService
+    ) {
         $this->orderRepository = $orderRepository;
+        $this->customerAssignmentService = $customerAssignmentService;
     }
 
     /**
@@ -44,11 +56,8 @@ public function execute(Observer $observer)
         if (array_key_exists('__sales_assign_order_id', $delegateData)) {
             $orderId = $delegateData['__sales_assign_order_id'];
             $order = $this->orderRepository->get($orderId);
-            if (!$order->getCustomerId()) {
-                //if customer ID wasn't already assigned then assigning.
-                $order->setCustomerId($customer->getId());
-                $order->setCustomerIsGuest(0);
-                $this->orderRepository->save($order);
+            if (!$order->getCustomerId() && $customer->getId()) {
+                $this->customerAssignmentService->execute($order, $customer);
             }
         }
     }
diff --git a/app/code/Magento/SalesRule/Observer/AssignCouponDataAfterOrderCustomerAssignObserver.php b/app/code/Magento/SalesRule/Observer/AssignCouponDataAfterOrderCustomerAssignObserver.php
new file mode 100644
index 0000000000000..d9699d334ff6a
--- /dev/null
+++ b/app/code/Magento/SalesRule/Observer/AssignCouponDataAfterOrderCustomerAssignObserver.php
@@ -0,0 +1,52 @@
+<?php
+
+/**
+ * Copyright © Magento, Inc. All rights reserved.
+ * See COPYING.txt for license details.
+ */
+
+declare(strict_types=1);
+
+namespace Magento\SalesRule\Observer;
+
+use Magento\Framework\Event\Observer;
+use Magento\SalesRule\Model\Coupon\UpdateCouponUsages;
+use Magento\Sales\Api\Data\OrderInterface;
+use Magento\Framework\Event\ObserverInterface;
+
+class AssignCouponDataAfterOrderCustomerAssignObserver implements ObserverInterface
+{
+    const EVENT_KEY_CUSTOMER = 'customer';
+
+    const EVENT_KEY_ORDER    = 'order';
+
+    /**
+     * @var UpdateCouponUsages
+     */
+    private $updateCouponUsages;
+
+    /**
+     * AssignCouponDataAfterOrderCustomerAssign constructor.
+     *
+     * @param UpdateCouponUsages $updateCouponUsages
+     */
+    public function __construct(
+        UpdateCouponUsages $updateCouponUsages
+    ) {
+        $this->updateCouponUsages = $updateCouponUsages;
+    }
+
+    /**
+     * @inheritDoc
+     */
+    public function execute(Observer $observer)
+    {
+        $event = $observer->getEvent();
+        /** @var OrderInterface $order */
+        $order = $event->getData(self::EVENT_KEY_ORDER);
+
+        if ($order->getCustomerId()) {
+            $this->updateCouponUsages->execute($order, true);
+        }
+    }
+}
diff --git a/app/code/Magento/SalesRule/etc/events.xml b/app/code/Magento/SalesRule/etc/events.xml
index 8261860bbb7ce..eec0da74f619e 100644
--- a/app/code/Magento/SalesRule/etc/events.xml
+++ b/app/code/Magento/SalesRule/etc/events.xml
@@ -24,4 +24,7 @@
     <event name="magento_salesrule_api_data_ruleinterface_load_after">
         <observer name="legacy_model_load" instance="Magento\Framework\EntityManager\Observer\AfterEntityLoad" />
     </event>
+    <event name="sales_order_customer_assign_after">
+        <observer name="sales_order_assign_customer_after" instance="Magento\SalesRule\Observer\AssignCouponDataAfterOrderCustomerAssignObserver" />
+    </event>
 </config>
diff --git a/dev/tests/integration/testsuite/Magento/SalesRule/Model/Observer/AssignCouponDataAfterOrderCustomerAssignTest.php b/dev/tests/integration/testsuite/Magento/SalesRule/Model/Observer/AssignCouponDataAfterOrderCustomerAssignTest.php
new file mode 100644
index 0000000000000..d04423daabdf9
--- /dev/null
+++ b/dev/tests/integration/testsuite/Magento/SalesRule/Model/Observer/AssignCouponDataAfterOrderCustomerAssignTest.php
@@ -0,0 +1,269 @@
+<?php
+
+use Magento\Sales\Model\Order;
+
+use Magento\Customer\Model\GroupManagement;
+use Magento\SalesRule\Api\CouponRepositoryInterface;
+use Magento\SalesRule\Model\Coupon;
+use Magento\SalesRule\Model\Rule;
+use Magento\Store\Model\StoreManagerInterface;
+use Magento\Customer\Model\Data\Customer;
+
+
+class AssignCouponDataAfterOrderCustomerAssignTest extends \PHPUnit\Framework\TestCase
+{
+    /**
+     * @var \Magento\Quote\Api\GuestCartManagementInterface
+     */
+    private $assignCouponToCustomerObserver;
+
+    /**
+     * @var Magento\Sales\Model\OrderRepository
+     */
+    private $orderRepository;
+
+    /**
+     * @var \Magento\Framework\ObjectManagerInterface
+     */
+    private $objectManager;
+
+    /**
+     * @var \Magento\Framework\Event\ManagerInterface
+     */
+    protected $eventManager;
+
+    /**
+     * @var Magento\Customer\Api\CustomerRepositoryInterface
+     */
+    private $customerRepository;
+
+    /**
+     * @var Order\OrderCustomerDelegate
+     */
+    private $delegateCustomerService;
+
+    /**
+     * @var Magento\SalesRule\Model\Rule\CustomerFactory
+     */
+    private $ruleCustomerFactory;
+
+    /**
+     * @inheritdoc
+     */
+    protected function setUp()
+    {
+        $this->objectManager = \Magento\TestFramework\Helper\Bootstrap::getObjectManager();
+        $this->eventManager = $this->createMock(\Magento\Framework\Event\ManagerInterface::class);
+        $this->orderRepository = $this->objectManager->get(Magento\Sales\Model\OrderRepository::class);
+        $this->delegateCustomerService = $this->objectManager->get(Order\OrderCustomerDelegate::class);
+        $this->customerRepository = $this->objectManager->get(\Magento\Customer\Api\CustomerRepositoryInterface::class);
+        $this->ruleCustomerFactory =  $this->objectManager->get(Magento\SalesRule\Model\Rule\CustomerFactory::class);;
+        $this->assignCouponToCustomerObserver = $this->objectManager->get(
+            Magento\SalesRule\Observer\AssignCouponDataAfterOrderCustomerAssignObserver::class
+        );
+    }
+
+    /**
+     * @magentoAppIsolation enabled
+     * @magentoDataFixture Magento/Sales/_files/order.php
+     */
+    public function testCouponDataHasBeenAssignedTest()
+    {
+        $rule = $this->prepareSalesRule();
+        $coupon = $this->attachSalesruleCoupon($rule);
+
+        $order  = $this->makeOrderWithCouponAsGuest($coupon);
+        $this->delegateOrderToBeAssigned($order);
+
+        $customer = $this->registerNewCustomer();
+        $ruleCustomer = $this->getSalesruleCustomerUsage($customer, $rule);
+
+        // Assert, that rule customer model has been created for specific customer
+        $this->assertEquals(
+            $ruleCustomer->getCustomerId(),
+            $customer->getId()
+        );
+
+        // Assert, that customer has increased coupon usage of specific rule
+        $this->assertEquals(
+            1,
+            $ruleCustomer->getTimesUsed()
+        );
+    }
+
+    /**
+     * @magentoAppIsolation enabled
+     * @magentoDataFixture Magento/Sales/_files/order.php
+     */
+    public function testOrderCancelingDecreasesCouponUsages()
+    {
+        $rule = $this->prepareSalesRule();
+        $coupon = $this->attachSalesruleCoupon($rule);
+
+        $order  = $this->makeOrderWithCouponAsGuest($coupon);
+        $this->delegateOrderToBeAssigned($order);
+
+        $customer = $this->registerNewCustomer();
+
+        $order->setCustomerId($customer->getId());
+        $this->processOrder($order);
+
+        // Should not throw exception as bux is fixed now
+        $this->cancelOrder($order);
+        $ruleCustomer = $this->getSalesruleCustomerUsage($customer, $rule);
+
+        // Assert, that rule customer model has been created for specific customer
+        $this->assertEquals(
+            $ruleCustomer->getCustomerId(),
+            $customer->getId()
+        );
+
+        // Assert, that customer has increased coupon usage of specific rule
+        $this->assertEquals(
+            0,
+            $ruleCustomer->getTimesUsed()
+        );
+
+    }
+
+    /**
+     * @param Order $order
+     * @return \Magento\Sales\Api\Data\OrderInterface
+     */
+    private function processOrder(Order $order)
+    {
+        $order->setState(\Magento\Sales\Model\Order::STATE_PROCESSING);
+        $order->setStatus(\Magento\Sales\Model\Order::STATE_PROCESSING);
+        return $this->orderRepository->save($order);
+    }
+
+    /**
+     * @param Order $order
+     */
+    private function cancelOrder(Order $order)
+    {
+        $order->cancel();
+    }
+
+    /**
+     * @param Customer $customer
+     * @param Rule $rule
+     * @return Rule\Customer
+     */
+    private function getSalesruleCustomerUsage(Customer $customer, Rule $rule) : Magento\SalesRule\Model\Rule\Customer
+    {
+        $ruleCustomer = $this->ruleCustomerFactory->create();
+        return $ruleCustomer->loadByCustomerRule($customer->getId(), $rule->getRuleId());
+    }
+
+    /**
+     * @return Rule
+     */
+    private function prepareSalesRule() : Rule
+    {
+        /** @var Rule $salesRule */
+        $salesRule = $this->objectManager->create(Rule::class);
+        $salesRule->setData(
+            [
+                'name' => '15$ fixed discount on whole cart',
+                'is_active' => 1,
+                'customer_group_ids' => [GroupManagement::NOT_LOGGED_IN_ID],
+                'coupon_type' => Rule::COUPON_TYPE_SPECIFIC,
+                'conditions' => [
+                    [
+                        'type' => \Magento\SalesRule\Model\Rule\Condition\Address::class,
+                        'attribute' => 'base_subtotal',
+                        'operator' => '>',
+                        'value' => 45,
+                    ],
+                ],
+                'simple_action' => Rule::CART_FIXED_ACTION,
+                'discount_amount' => 15,
+                'discount_step' => 0,
+                'stop_rules_processing' => 1,
+                'website_ids' => [
+                    $this->objectManager->get(StoreManagerInterface::class)->getWebsite()->getId(),
+                ],
+            ]
+        );
+        $this->objectManager->get(
+            \Magento\SalesRule\Model\ResourceModel\Rule::class
+        )->save($salesRule);
+
+        return $salesRule;
+    }
+
+    /**
+     * @param Rule $salesRule
+     * @return Coupon
+     */
+    private function attachSalesruleCoupon(Rule $salesRule) : Coupon
+    {
+        $coupon = $this->objectManager->create(Coupon::class);
+        $coupon->setRuleId($salesRule->getId())
+            ->setCode('CART_FIXED_DISCOUNT_15')
+            ->setType(0);
+
+        $this->objectManager->get(CouponRepositoryInterface::class)->save($coupon);
+
+        return $coupon;
+    }
+
+    /**
+     * @param Coupon $coupon
+     * @return Order
+     */
+    private function makeOrderWithCouponAsGuest(Coupon $coupon) : Order
+    {
+        $order = $this->objectManager->create(\Magento\Sales\Model\Order::class);
+        $order->loadByIncrementId('100000001')
+            ->setCustomerIsGuest(true)
+            ->setCouponCode($coupon->getCode())
+            ->setCreatedAt('2014-10-25 10:10:10')
+            ->setAppliedRuleIds($coupon->getRuleId())
+            ->save();
+
+        return $order;
+    }
+
+    /**
+     * @param Order $order
+     */
+    private function delegateOrderToBeAssigned(Order $order)
+    {
+        $this->delegateCustomerService->delegateNew($order->getId());
+    }
+
+    /**
+     * @return Customer
+     * @throws \Magento\Framework\Exception\InputException
+     * @throws \Magento\Framework\Exception\LocalizedException
+     * @throws \Magento\Framework\Exception\State\InputMismatchException
+     */
+    private function registerNewCustomer() : Customer
+    {
+        $customer = $this->objectManager->create(
+            \Magento\Customer\Api\Data\CustomerInterface::class
+        );
+
+        /** @var Magento\Customer\Api\Data\CustomerInterface $customer */
+        $customer->setWebsiteId(1)
+            ->setEmail('customer@example.com')
+            ->setGroupId(1)
+            ->setStoreId(1)
+            ->setPrefix('Mr.')
+            ->setFirstname('John')
+            ->setMiddlename('A')
+            ->setLastname('Smith')
+            ->setSuffix('Esq.')
+            ->setDefaultBilling(1)
+            ->setDefaultShipping(1)
+            ->setTaxvat('12')
+            ->setGender(0);
+
+        $customer = $this->customerRepository->save($customer, 'password');
+
+        return $customer;
+    }
+}
+