Customer Account API Removes Checkout Classic Schema in Version 2026-10

Shopify removes the deprecated Customer.lastIncompleteCheckout field from the Customer Account API starting with version 2026-10. This removal eliminates the entire Checkout Classic schema subtree that became unreachable after the field’s deprecation.

Removed Types and Fields

The removal affects nine types and fields from the Customer Account API:

• Customer.lastIncompleteCheckout (parent field)
• Checkout type
• Checkout.appliedGiftCards
• AppliedGiftCard
• AvailableShippingRates
• CheckoutLineItem
• CheckoutLineItemConnection
• CheckoutLineItemEdge
• ShippingRate

The Customer.lastIncompleteCheckout field returned null since its deprecation, making the associated Checkout types functionally inaccessible before this version.

Impact on Developers

Developers using Customer Account API version 2026-10 or later cannot query these Checkout Classic fields. Applications that reference these types in their GraphQL queries will receive schema validation errors.

This cleanup removes legacy Checkout Classic references from the API surface. Developers working with incomplete checkouts need to use current checkout management approaches rather than the deprecated Customer Account API fields.

Migration Considerations

Review your Customer Account API queries for references to lastIncompleteCheckout or related Checkout types. Applications pinned to API versions before 2026-10 continue to function but should plan migration paths away from these removed fields. The change affects only the Customer Account API schema and does not impact other Shopify APIs that handle checkout operations.

Read the full announcement →