---
title: cartDiscountCodesUpdate - Storefront API
description: Updates the discount codes applied to the cart.
api_version: 2025-10
api_name: storefront
type: mutation
api_type: graphql
source_url:
  html: https://shopify.dev/docs/api/storefront/latest/mutations/cartDiscountCodesUpdate
  md: https://shopify.dev/docs/api/storefront/latest/mutations/cartDiscountCodesUpdate.md
---

# cart​Discount​Codes​Update

mutation

Updates the discount codes applied to the cart.

## Arguments

* cart​Id

  [ID!](https://shopify.dev/docs/api/storefront/latest/scalars/ID)

  required

  The ID of the cart.

* discount​Codes

  [\[String!\]](https://shopify.dev/docs/api/storefront/latest/scalars/String)

  The case-insensitive discount codes that the customer added at checkout.

  The input must not contain more than `250` values.

***

## Cart​Discount​Codes​Update​Payload returns

* cart

  [Cart](https://shopify.dev/docs/api/storefront/latest/objects/Cart)

  The updated cart.

* user​Errors

  [\[Cart​User​Error!\]!](https://shopify.dev/docs/api/storefront/latest/objects/CartUserError)

  non-null

  The list of errors that occurred from executing the mutation.

* warnings

  [\[Cart​Warning!\]!](https://shopify.dev/docs/api/storefront/latest/objects/CartWarning)

  non-null

  A list of warnings that occurred during the mutation.

***

## Examples

* ### cartDiscountCodesUpdate reference

## Mutation Reference

```graphql
mutation cartDiscountCodesUpdate($cartId: ID!, $discountCodes: [String!]) {
  cartDiscountCodesUpdate(cartId: $cartId, discountCodes: $discountCodes) {
    cart {
      # Cart fields
    }
    userErrors {
      field
      message
    }
    warnings {
      # CartWarning fields
    }
  }
}
```

## Input

```json
{
  "cartId": "gid://shopify/<objectName>/10079785100",
  "discountCodes": [
    "<your-discountCodes>"
  ]
}
```