diff --git a/app/code/Magento/QuoteGraphQl/Model/Resolver/SetPaymentMethodOnCart.php b/app/code/Magento/QuoteGraphQl/Model/Resolver/SetPaymentMethodOnCart.php
index a93c8032c99..d1dcb4a48a7 100644
--- a/app/code/Magento/QuoteGraphQl/Model/Resolver/SetPaymentMethodOnCart.php
+++ b/app/code/Magento/QuoteGraphQl/Model/Resolver/SetPaymentMethodOnCart.php
@@ -60,12 +60,12 @@ public function __construct(
     public function resolve(Field $field, $context, ResolveInfo $info, array $value = null, array $args = null)
     {
         if (!isset($args['input']['cart_id']) || empty($args['input']['cart_id'])) {
-            throw new GraphQlInputException(__('Required parameter "cart_id" is missing'));
+            throw new GraphQlInputException(__('Required parameter "cart_id" is missing.'));
         }
         $maskedCartId = $args['input']['cart_id'];
 
         if (!isset($args['input']['payment_method']['code']) || empty($args['input']['payment_method']['code'])) {
-            throw new GraphQlInputException(__('Required parameter "payment_method" is missing'));
+            throw new GraphQlInputException(__('Required parameter "code" for "payment_method" is missing.'));
         }
         $paymentMethodCode = $args['input']['payment_method']['code'];
 
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 c7da2144adb..51c48f5041d 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
@@ -171,6 +171,54 @@ public function testPaymentMethodOnNonExistentCart()
         $this->graphQlQuery($query, [], '', $this->getHeaderMap());
     }
 
+    /**
+     * @magentoApiDataFixture Magento/Customer/_files/customer.php
+     * @magentoApiDataFixture Magento/Checkout/_files/quote_with_address_saved.php
+     * @param string $input
+     * @param string $message
+     * @dataProvider dataProviderSetPaymentMethodWithoutRequiredParameters
+     */
+    public function testSetPaymentMethodWithoutRequiredParameters(string $input, string $message)
+    {
+        $query = <<<QUERY
+mutation {
+  setPaymentMethodOnCart(
+    input: {
+      {$input}
+    }
+  ) {
+    cart {
+      items {
+        qty
+      }
+    }
+  }
+}
+QUERY;
+        $this->expectExceptionMessage($message);
+        $this->graphQlQuery($query, [], '', $this->getHeaderMap());
+    }
+    /**
+     * @return array
+     */
+    public function dataProviderSetPaymentMethodWithoutRequiredParameters(): array
+    {
+        return [
+            'missed_cart_id' => [
+                'payment_method: {code: "' . Checkmo::PAYMENT_METHOD_CHECKMO_CODE . '"}',
+                'Required parameter "cart_id" is missing.'
+            ],
+            'missed_payment_method' => [
+                'cart_id: "test"',
+                'Required parameter "code" for "payment_method" is missing.'
+            ],
+            'missed_payment_method_code' => [
+                'cart_id: "test", payment_method: {code: ""}',
+                'Required parameter "code" for "payment_method" is missing.'
+            ],
+        ];
+    }
+
     /**
      * @magentoApiDataFixture Magento/Checkout/_files/quote_with_payment_saved.php
      */
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 182bbaf6185..017b85ba17b 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 +126,53 @@ public function testSetPaymentMethodToCustomerCart()
         $this->graphQlQuery($query);
     }
 
+    /**
+     * @magentoApiDataFixture Magento/Checkout/_files/quote_with_address_saved.php
+     * @param string $input
+     * @param string $message
+     * @dataProvider dataProviderSetPaymentMethodWithoutRequiredParameters
+     */
+    public function testSetPaymentMethodWithoutRequiredParameters(string $input, string $message)
+    {
+        $query = <<<QUERY
+mutation {
+  setPaymentMethodOnCart(
+    input: {
+      {$input}
+    }
+  ) {
+    cart {
+      items {
+        qty
+      }
+    }
+  }
+}
+QUERY;
+        $this->expectExceptionMessage($message);
+        $this->graphQlQuery($query);
+    }
+    /**
+     * @return array
+     */
+    public function dataProviderSetPaymentMethodWithoutRequiredParameters(): array
+    {
+        return [
+            'missed_cart_id' => [
+                'payment_method: {code: "' . Checkmo::PAYMENT_METHOD_CHECKMO_CODE . '"}',
+                'Required parameter "cart_id" is missing.'
+            ],
+            'missed_payment_method' => [
+                'cart_id: "test"',
+                'Required parameter "code" for "payment_method" is missing.'
+            ],
+            'missed_payment_method_code' => [
+                'cart_id: "test", payment_method: {code: ""}',
+                'Required parameter "code" for "payment_method" is missing.'
+            ],
+        ];
+    }
+
     /**
      * @expectedException \Exception
      * @expectedExceptionMessage Could not find a cart with ID "non_existent_masked_id"