diff --git a/dev/tests/api-functional/testsuite/Magento/GraphQl/Quote/Customer/SetBillingAddressOnCartTest.php b/dev/tests/api-functional/testsuite/Magento/GraphQl/Quote/Customer/SetBillingAddressOnCartTest.php
index 1a93c011e80a..ccd328cea12e 100644
--- a/dev/tests/api-functional/testsuite/Magento/GraphQl/Quote/Customer/SetBillingAddressOnCartTest.php
+++ b/dev/tests/api-functional/testsuite/Magento/GraphQl/Quote/Customer/SetBillingAddressOnCartTest.php
@@ -403,6 +403,26 @@ public function testSetBillingAddressIfCustomerIsNotOwnerOfAddress()
         $this->graphQlQuery($query, [], '', $this->getHeaderMap('customer2@search.example.com'));
     }
 
+    /**
+     * @magentoApiDataFixture Magento/Customer/_files/customer.php
+     * @expectedException \Exception
+     * @expectedExceptionMessage Could not find a cart with ID "non_existent_masked_id"
+     */
+    public function testSetBillingAddressOnNonExistentCart()
+    {
+        $maskedQuoteId = 'non_existent_masked_id';
+        $query = <<<QUERY
+{
+  cart(cart_id: "$maskedQuoteId") {
+    items {
+      id
+    }
+  }
+}
+QUERY;
+        $this->graphQlQuery($query, [], '', $this->getHeaderMap());
+    }
+
     /**
      * Verify the all the whitelisted fields for a New Address Object
      *
diff --git a/dev/tests/api-functional/testsuite/Magento/GraphQl/Quote/Customer/SetPaymentMethodOnCartTest.php b/dev/tests/api-functional/testsuite/Magento/GraphQl/Quote/Customer/SetPaymentMethodOnCartTest.php
index bbc77b6c3974..91c98d2f13f4 100644
--- a/dev/tests/api-functional/testsuite/Magento/GraphQl/Quote/Customer/SetPaymentMethodOnCartTest.php
+++ b/dev/tests/api-functional/testsuite/Magento/GraphQl/Quote/Customer/SetPaymentMethodOnCartTest.php
@@ -151,6 +151,26 @@ public function testSetPaymentMethodToAnotherCustomerCart()
         $this->graphQlQuery($query, [], '', $this->getHeaderMap('customer2@search.example.com'));
     }
 
+    /**
+     * @magentoApiDataFixture Magento/Customer/_files/customer.php
+     * @expectedException \Exception
+     * @expectedExceptionMessage Could not find a cart with ID "non_existent_masked_id"
+     */
+    public function testPaymentMethodOnNonExistentCart()
+    {
+        $maskedQuoteId = 'non_existent_masked_id';
+        $query = <<<QUERY
+{
+  cart(cart_id: "$maskedQuoteId") {
+    items {
+      id
+    }
+  }
+}
+QUERY;
+        $this->graphQlQuery($query, [], '', $this->getHeaderMap());
+    }
+
     /**
      * @param string $maskedQuoteId
      * @param string $methodCode
diff --git a/dev/tests/api-functional/testsuite/Magento/GraphQl/Quote/Guest/SetBillingAddressOnCartTest.php b/dev/tests/api-functional/testsuite/Magento/GraphQl/Quote/Guest/SetBillingAddressOnCartTest.php
index 880d6aa0f406..8f8e5419a9ff 100644
--- a/dev/tests/api-functional/testsuite/Magento/GraphQl/Quote/Guest/SetBillingAddressOnCartTest.php
+++ b/dev/tests/api-functional/testsuite/Magento/GraphQl/Quote/Guest/SetBillingAddressOnCartTest.php
@@ -244,6 +244,25 @@ public function testSetBillingAddressFromAddressBook()
         $this->graphQlQuery($query);
     }
 
+    /**
+     * @expectedException \Exception
+     * @expectedExceptionMessage Could not find a cart with ID "non_existent_masked_id"
+     */
+    public function testSetBillingAddressOnNonExistentCart()
+    {
+        $maskedQuoteId = 'non_existent_masked_id';
+        $query = <<<QUERY
+{
+  cart(cart_id: "$maskedQuoteId") {
+    items {
+      id
+    }
+  }
+}
+QUERY;
+        $this->graphQlQuery($query);
+    }
+
     /**
      * Verify the all the whitelisted fields for a New Address Object
      *
diff --git a/dev/tests/api-functional/testsuite/Magento/GraphQl/Quote/Guest/SetPaymentMethodOnCartTest.php b/dev/tests/api-functional/testsuite/Magento/GraphQl/Quote/Guest/SetPaymentMethodOnCartTest.php
index 7484b2af7569..fbfa53b7d643 100644
--- a/dev/tests/api-functional/testsuite/Magento/GraphQl/Quote/Guest/SetPaymentMethodOnCartTest.php
+++ b/dev/tests/api-functional/testsuite/Magento/GraphQl/Quote/Guest/SetPaymentMethodOnCartTest.php
@@ -126,6 +126,25 @@ public function testSetPaymentMethodToCustomerCart()
         $this->graphQlQuery($query);
     }
 
+    /**
+     * @expectedException \Exception
+     * @expectedExceptionMessage Could not find a cart with ID "non_existent_masked_id"
+     */
+    public function testSetPaymentOnNonExistentCart()
+    {
+        $maskedQuoteId = 'non_existent_masked_id';
+        $query = <<<QUERY
+{
+  cart(cart_id: "$maskedQuoteId") {
+    items {
+      id
+    }
+  }
+}
+QUERY;
+        $this->graphQlQuery($query);
+    }
+
     /**
      * @param string $maskedQuoteId
      * @param string $methodCode