ST-2026-108 · Removals & lifecycle enforcement
Shopify schedules Customer.lastIncompleteCheckout removal for API 2026-10
Shopify Customer Account API version 2026-10 removes the already-deprecated Customer.lastIncompleteCheckout field and its now-unreachable Checkout type subtree when that stable version releases on 1 October 2026.
Previous state
Before Customer Account API version 2026-10, the deprecated Customer.lastIncompleteCheckout field remained in the schema but returned null, leaving its Checkout Classic type subtree reachable only through that stale field.
Current state
Customer Account API version 2026-10 removes Customer.lastIncompleteCheckout and the now-unreachable Checkout, AppliedGiftCard, AvailableShippingRates, CheckoutLineItem connection and ShippingRate types named in Shopify's notice.
Affected users
Who needs to care
Apps whose Customer Account API GraphQL queries select Customer.lastIncompleteCheckout or nested fields on its Checkout object and that plan to adopt API version 2026-10.
Required response
What to do
Remove Customer.lastIncompleteCheckout and nested Checkout selections before upgrading to 2026-10. Use Storefront API cart flows for active buyer cart or checkout state, or Customer.orders for completed purchase history, according to the required workload.
Evidence boundary
What the source does not prove
There is no replacement field in the Customer Account API. The removal is version-bound to 2026-10 rather than effective on the 6 July announcement date; the notice does not remove checkout concepts from the Storefront API or completed history from Customer.orders.
Lifecycle history
Dated event sequence
- Breaking change announced
Shopify identified the field and Checkout subtree that will be absent from Customer Account API 2026-10 and published the bounded migration paths.
- API 2026-10 stable release
The removal takes effect for requests using Customer Account API version 2026-10.
Evidence ledger
First-party sources
- 01Shopify — Customer Account API Customer.lastIncompleteCheckout and Checkout types removed in 2026-10
Official Shopify developer changelog · 2026-07-06
Open official source ↗ - 02Shopify — About Shopify API versioning
Official Shopify API release schedule · 2026-09-04
Open official source ↗