diff --git a/api-specs/checkout/examples/payments/cancelPaymentAction.json b/api-specs/checkout/examples/payments/cancelPaymentAction.json
index e630f38b9..67fe54301 100644
--- a/api-specs/checkout/examples/payments/cancelPaymentAction.json
+++ b/api-specs/checkout/examples/payments/cancelPaymentAction.json
@@ -1,3 +1,4 @@
 {
-  "action": "cancelPayment"
-}
+  "action": "cancelPayment",
+  "merchantReference": "example-reference"
+}
\ No newline at end of file
diff --git a/api-specs/checkout/examples/payments/capturePayment.json b/api-specs/checkout/examples/payments/capturePayment.json
index 6ec86e51b..7e3bd88d3 100644
--- a/api-specs/checkout/examples/payments/capturePayment.json
+++ b/api-specs/checkout/examples/payments/capturePayment.json
@@ -5,7 +5,8 @@
       "amount": {
         "centAmount": 10000,
         "currencyCode": "EUR"
-      }
+      },
+      "merchantReference": "example-reference"
     }
   ]
-}
+}
\ No newline at end of file
diff --git a/api-specs/checkout/examples/payments/capturePaymentAction.json b/api-specs/checkout/examples/payments/capturePaymentAction.json
index 5daa0341a..c23afd3dc 100644
--- a/api-specs/checkout/examples/payments/capturePaymentAction.json
+++ b/api-specs/checkout/examples/payments/capturePaymentAction.json
@@ -3,5 +3,6 @@
   "amount": {
     "centAmount": 10000,
     "currencyCode": "EUR"
-  }
-}
+  },
+  "merchantReference": "example-reference"
+}
\ No newline at end of file
diff --git a/api-specs/checkout/examples/payments/refundPaymentAction.json b/api-specs/checkout/examples/payments/refundPaymentAction.json
index d7da448c6..72c497d0e 100644
--- a/api-specs/checkout/examples/payments/refundPaymentAction.json
+++ b/api-specs/checkout/examples/payments/refundPaymentAction.json
@@ -3,5 +3,6 @@
   "amount": {
     "centAmount": 10000,
     "currencyCode": "EUR"
-  }
-}
+  },
+  "merchantReference": "example-reference"
+}
\ No newline at end of file
diff --git a/api-specs/checkout/types/payment-intents/PaymentIntentAction.raml b/api-specs/checkout/types/payment-intents/PaymentIntentAction.raml
index eaf7838ae..29b34aeff 100644
--- a/api-specs/checkout/types/payment-intents/PaymentIntentAction.raml
+++ b/api-specs/checkout/types/payment-intents/PaymentIntentAction.raml
@@ -8,8 +8,12 @@ properties:
   action:
     type: PaymentIntentOperation
     description: |
-      Action to execute for the given Payment.
+      Action to execute for the given [Payment](/../api/projects/payments#payment).
   amount?:
     type: common.Amount
     description: |
       Amount to be captured or refunded.
+  merchantReference?:
+    type: string
+    description: |
+      A merchant-defined identifier associated with the Payment to track and reconcile the Payment Intent Action on the merchant's side. For example, an invoice number.
diff --git a/api-specs/checkout/types/payment-intents/PaymentIntentCancelAction.raml b/api-specs/checkout/types/payment-intents/PaymentIntentCancelAction.raml
index b6ce4be8f..46b15535a 100644
--- a/api-specs/checkout/types/payment-intents/PaymentIntentCancelAction.raml
+++ b/api-specs/checkout/types/payment-intents/PaymentIntentCancelAction.raml
@@ -13,3 +13,7 @@ description: |
 properties:
   action:
     type: string
+  merchantReference?:
+    type: string
+    description: |
+      A merchant-defined identifier associated with the [Payment](/../api/projects/payments#payment) to track and reconcile the [Payment Intent Action](ctp:checkout:type:PaymentIntentAction) on the merchant's side. For example, an invoice number.
diff --git a/api-specs/checkout/types/payment-intents/PaymentIntentCaptureAction.raml b/api-specs/checkout/types/payment-intents/PaymentIntentCaptureAction.raml
index fda413c1d..80548c39b 100644
--- a/api-specs/checkout/types/payment-intents/PaymentIntentCaptureAction.raml
+++ b/api-specs/checkout/types/payment-intents/PaymentIntentCaptureAction.raml
@@ -15,3 +15,7 @@ properties:
     description: |
       Amount to be captured. It must be less than or equal to the [authorized](/payments-lifecycle#authorization) amount.
     type: common.Amount
+  merchantReference?:
+    type: string
+    description: |
+      A merchant-defined identifier associated with the [Payment](/../api/projects/payments#payment) to track and reconcile the [Payment Intent Action](ctp:checkout:type:PaymentIntentAction) on the merchant's side. For example, an invoice number.
diff --git a/api-specs/checkout/types/payment-intents/PaymentIntentRefundAction.raml b/api-specs/checkout/types/payment-intents/PaymentIntentRefundAction.raml
index 3bde27c67..1881ea91c 100644
--- a/api-specs/checkout/types/payment-intents/PaymentIntentRefundAction.raml
+++ b/api-specs/checkout/types/payment-intents/PaymentIntentRefundAction.raml
@@ -11,7 +11,11 @@ description: |
 properties:
   action:
     type: string
-  amount?:
+  amount:
     description: |
       Amount to be refunded. It must be less than or equal to the [captured](/payments-lifecycle#payment-capture) amount.
     type: common.Amount
+  merchantReference?:
+    type: string
+    description: |
+      A merchant-defined identifier associated with the [Payment](/../api/projects/payments#payment) to track and reconcile the [Payment Intent Action](ctp:checkout:type:PaymentIntentAction) on the merchant's side. For example, an invoice number.