---
title: cartBuyerIdentityUpdate - Storefront API
description: |
  Updates customer information associated with a cart.
  Buyer identity is used to determine
  [international pricing](https://shopify.dev/custom-storefronts/internationalization/international-pricing)
  and should match the customer's shipping address.
api_version: 2025-10
api_name: storefront
type: mutation
api_type: graphql
source_url:
  html: https://shopify.dev/docs/api/storefront/latest/mutations/cartBuyerIdentityUpdate
  md: https://shopify.dev/docs/api/storefront/latest/mutations/cartBuyerIdentityUpdate.md
---

# cart​Buyer​Identity​Update

mutation

Updates customer information associated with a cart. Buyer identity is used to determine [international pricing](https://shopify.dev/custom-storefronts/internationalization/international-pricing) and should match the customer's shipping address.

## Arguments

* buyer​Identity

  [Cart​Buyer​Identity​Input!](https://shopify.dev/docs/api/storefront/latest/input-objects/CartBuyerIdentityInput)

  required

  The customer associated with the cart. Used to determine [international pricing](https://shopify.dev/custom-storefronts/internationalization/international-pricing). Buyer identity should match the customer's shipping address.

* cart​Id

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

  required

  The ID of the cart.

***

## Cart​Buyer​Identity​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

* ### cartBuyerIdentityUpdate reference

## Mutation Reference

```graphql
mutation cartBuyerIdentityUpdate($cartId: ID!, $buyerIdentity: CartBuyerIdentityInput!) {
  cartBuyerIdentityUpdate(cartId: $cartId, buyerIdentity: $buyerIdentity) {
    cart {
      # Cart fields
    }
    userErrors {
      field
      message
    }
    warnings {
      # CartWarning fields
    }
  }
}
```

## Input

```json
{
  "cartId": "gid://shopify/<objectName>/10079785100",
  "buyerIdentity": {
    "email": "<your-email>",
    "phone": "<your-phone>",
    "companyLocationId": "gid://shopify/<objectName>/10079785100",
    "countryCode": "AF",
    "customerAccessToken": "<your-customerAccessToken>",
    "preferences": {
      "delivery": {},
      "wallet": [
        "<your-wallet>"
      ]
    }
  }
}
```

##### Variables

```
{
  "cartId": "gid://shopify/<objectName>/10079785100",
  "buyerIdentity": {
    "email": "<your-email>",
    "phone": "<your-phone>",
    "companyLocationId": "gid://shopify/<objectName>/10079785100",
    "countryCode": "AF",
    "customerAccessToken": "<your-customerAccessToken>",
    "preferences": {
      "delivery": {},
      "wallet": [
        "<your-wallet>"
      ]
    }
  }
}
```

##### Schema

```
input CartBuyerIdentityInput {
  email: String
  phone: String
  companyLocationId: ID
  countryCode: CountryCode
  customerAccessToken: String
  preferences: CartPreferencesInput
}

input CartPreferencesInput {
  delivery: CartDeliveryPreferenceInput
  wallet: [String!]
}
```