diff --git a/packages/core/src/cart/cart.ts b/packages/core/src/cart/cart.ts
index 6b578c44c8..b0461644e4 100644
--- a/packages/core/src/cart/cart.ts
+++ b/packages/core/src/cart/cart.ts
@@ -35,4 +35,5 @@ export default interface Cart {
     createdTime: string;
     updatedTime: string;
     source?: CartSource;
+    version: number;
 }
diff --git a/packages/core/src/cart/carts.mock.ts b/packages/core/src/cart/carts.mock.ts
index a6bee962f7..4e945c0abe 100644
--- a/packages/core/src/cart/carts.mock.ts
+++ b/packages/core/src/cart/carts.mock.ts
@@ -26,6 +26,7 @@ export function getCart(): Cart {
         },
         createdTime: '2018-03-06T04:41:49+00:00',
         updatedTime: '2018-03-07T03:44:51+00:00',
+        version: 2,
     };
 }
 
diff --git a/packages/core/src/checkout/checkout.ts b/packages/core/src/checkout/checkout.ts
index 88afdcc786..410f2dd319 100644
--- a/packages/core/src/checkout/checkout.ts
+++ b/packages/core/src/checkout/checkout.ts
@@ -43,6 +43,7 @@ export default interface Checkout {
     payments?: CheckoutPayment[];
     channelId: number;
     fees: Fee[];
+    version: number;
 }
 
 export interface CheckoutRequestBody {
diff --git a/packages/core/src/checkout/checkouts.mock.ts b/packages/core/src/checkout/checkouts.mock.ts
index d3cf3a8987..7c2d2723ed 100644
--- a/packages/core/src/checkout/checkouts.mock.ts
+++ b/packages/core/src/checkout/checkouts.mock.ts
@@ -67,6 +67,7 @@ export function getCheckout(): Checkout {
         ],
         channelId: 1,
         fees: [],
+        version: 2,
     };
 }
 
diff --git a/packages/payment-integration-api/src/cart/cart.ts b/packages/payment-integration-api/src/cart/cart.ts
index 88456f3dba..e9ef318923 100644
--- a/packages/payment-integration-api/src/cart/cart.ts
+++ b/packages/payment-integration-api/src/cart/cart.ts
@@ -20,4 +20,5 @@ export default interface Cart {
     createdTime: string;
     updatedTime: string;
     source?: CartSource;
+    version: number;
 }
diff --git a/packages/payment-integration-api/src/checkout/checkout.ts b/packages/payment-integration-api/src/checkout/checkout.ts
index 6cf0a20e22..4552d90af2 100644
--- a/packages/payment-integration-api/src/checkout/checkout.ts
+++ b/packages/payment-integration-api/src/checkout/checkout.ts
@@ -40,6 +40,7 @@ export default interface Checkout {
     createdTime: string;
     updatedTime: string;
     payments?: CheckoutPayment[];
+    version: number;
 }
 
 export interface CheckoutRequestBody {
diff --git a/packages/payment-integration-api/src/mocks/carts.mock.ts b/packages/payment-integration-api/src/mocks/carts.mock.ts
index ee5d97d7f0..bc0f445fe3 100644
--- a/packages/payment-integration-api/src/mocks/carts.mock.ts
+++ b/packages/payment-integration-api/src/mocks/carts.mock.ts
@@ -30,6 +30,7 @@ export default function getCart(): Cart {
         },
         createdTime: '2018-03-06T04:41:49+00:00',
         updatedTime: '2018-03-07T03:44:51+00:00',
+        version: 2,
     };
 }
 
diff --git a/packages/payment-integrations-test-utils/src/test-utils/carts.mock.ts b/packages/payment-integrations-test-utils/src/test-utils/carts.mock.ts
index 3960ea4e00..bbcae338b7 100644
--- a/packages/payment-integrations-test-utils/src/test-utils/carts.mock.ts
+++ b/packages/payment-integrations-test-utils/src/test-utils/carts.mock.ts
@@ -30,6 +30,7 @@ export default function getCart(): Cart {
         },
         createdTime: '2018-03-06T04:41:49+00:00',
         updatedTime: '2018-03-07T03:44:51+00:00',
+        version: 2,
     };
 }
 
diff --git a/packages/payment-integrations-test-utils/src/test-utils/checkouts.mock.ts b/packages/payment-integrations-test-utils/src/test-utils/checkouts.mock.ts
index e83586df2e..357c778511 100644
--- a/packages/payment-integrations-test-utils/src/test-utils/checkouts.mock.ts
+++ b/packages/payment-integrations-test-utils/src/test-utils/checkouts.mock.ts
@@ -47,6 +47,7 @@ export default function getCheckout(): Checkout {
                 ],
             },
         ],
+        version: 2,
     };
 }