Checkout.liquid Is Gone: What Still Breaks After August 26, 2026

Checkout.liquid stopped working on in-checkout pages on August 13, 2024. The additional scripts box became view-only on August 28, 2025. Shopify Scripts were switched off on June 30, 2026. And for Basic and Advanced stores, the remaining checkout.liquid customisations were removed automatically on August 26, 2026, after Shopify Plus stores hit their own deadline on August 28, 2025. If your checkout still leans on any of those hooks, it is not a matter of when it breaks. It broke, and the only question is whether anyone has noticed yet.

Checkout Extensibility replaced it: a structured, app-based framework built around three components. Checkout UI extensions place approved components, banners, custom fields, upsell offers, trust badges, into fixed extension points. Shopify Functions run server-side logic like discount calculations, payment method filtering, and shipping rate customisation. The Checkout Branding API controls the visual layer, colours, fonts, corner radius, logo placement. Every extension automatically inherits the branding, so you are not re-styling the same components twice.

What moved, and what did not

Most day-to-day checkout customisation does not need Shopify Plus. Branding, custom fields, and payment and shipping ordering all work through installed apps on any plan. Apps that customise the thank-you and order status pages work on Basic and higher. What stays locked to Plus is narrower: checkout UI extensions on the information, shipping, and payment steps, the Checkout Branding API for deeper styling, and custom apps that contain Functions. Public App Store apps that contain Functions work on any plan.

Four things stay locked regardless of plan tier, and they are architectural limits, not pricing restrictions: the checkout page sequence, arbitrary JavaScript, card data access, and the order-submission step. If your old checkout.liquid relied on any of those, there is no extension that restores it, and the rebuild is a redesign, not a migration.

The migration itself has hard edges worth knowing. Merchants can add up to three checkout UI extensions to the same block target, and each extension's compiled bundle is capped at 64 KB. The post-purchase page will not show if the buyer pays with a wallet, an installment service, a gift card, or another method that is not a credit card. And discount, delivery, and payment logic now runs on Shopify Functions, which is real development work, not a settings toggle. Tiered discounts, B2B pricing, and conditional payment rules are where merchants typically need to hire a developer.

The audit, in order

First, list every checkout customisation you have and sort it into three piles: what runs on UI extensions, what runs on Functions, and what relied on checkout.liquid or Scripts and has no replacement. The third pile is the work. Second, check the thank-you and order status pages, which work on every plan and are the most commonly forgotten surface in a migration. Third, test with a real cart on every payment method you accept, because the post-purchase gaps only appear for wallet and installment payments, and those are the payments your test card never uses.

The deadline has passed, which means the migration is no longer a project with a date. It is a live defect with a symptom list: missing custom fields, discount logic that silently stopped applying, branding that reverted to defaults, and a thank-you page that looks like nobody owns it. Check the checkout with a real order, not a preview, and fix the third pile first. The rest is configuration.

Keep reading: Checkout UI Extensions: Three Per Target, 64 KB, No Exceptions, Custom-App Functions Need Plus. Public-App Functions Do Not, Shopify Web Pixels: What Actually Fires at Checkout, and What Cannot.

Frequently asked questions

When did checkout.liquid stop working?

It stopped working on in-checkout pages on August 13, 2024. Shopify Plus stores hit the upgrade deadline on August 28, 2025, and non-Plus stores had until August 26, 2026, before Shopify auto-removed remaining customisations.

What replaced checkout.liquid?

Checkout Extensibility: checkout UI extensions for what the buyer sees, Shopify Functions for server-side logic like discounts and payment rules, and the Checkout Branding API for deeper styling.

Do I need Shopify Plus to customise checkout?

Not for most day-to-day customisation. Branding, custom fields, and thank-you page apps work on every plan. UI extensions on the information, shipping, and payment steps and the Branding API are Plus-only.

What can never be customised in checkout?

Four things are locked on every plan: the checkout page sequence, arbitrary JavaScript, card data access, and the order-submission step. Those are architectural limits, not pricing restrictions.