The End of checkout.liquid
For years, Plus merchants customised checkout with checkout.liquid and the Additional Scripts box. Both are being retired in favour of Checkout Extensibility — Shopify's modern, upgrade-safe way to customise checkout. The Additional Scripts box is now view-only on upgraded stores, and custom checkout.liquid no longer renders. If your store still depends on them, it is time to move.
What Is Checkout Extensibility?
Checkout Extensibility is a set of modern, app-based tools for customising checkout that survive Shopify updates automatically. Instead of editing a fragile Liquid template, you add structured extensions that Shopify maintains across upgrades — so your customisations never break when checkout changes.
The Four Building Blocks
1. Checkout UI extensions — React-style components that render inside checkout: banners, custom fields, trust messaging, upsells and conditional content 2. Functions — server-side logic for discounts, delivery customisation, payment method sorting and cart validation 3. Web pixel extensions — privacy-safe analytics and tracking 4. Payments extensions — custom payment method behaviour
What You Can Customise Now
- Branding: colours, fonts and layout through the checkout editor
- Custom fields (gift messages, GST numbers, delivery instructions)
- Trust badges, banners and conditional messaging
- Discounts, shipping and payment logic via Functions
- Upsells and cross-sells inside checkout
How to Migrate Your Checkout
1. Inventory every current customisation in checkout.liquid and Additional Scripts 2. Map each one to the right tool: editor setting, UI extension, Function or web pixel 3. Rebuild them as extensions with the Shopify CLI 4. Test the full checkout flow, including analytics and tax or GST fields 5. Go live and confirm tracking and conversions are intact
For related conversion work, see our checkout optimization guide.
Why This Is Actually Good News
Checkout Extensibility is faster, more secure, and upgrade-safe — your customisations keep working as Shopify evolves. It also unlocks Shop Pay and one-page checkout performance you could never match with old scripts. The migration is real work, but the result is a checkout that is both more capable and far less fragile.
Need to move off checkout.liquid? ANF STUDIO rebuilds custom checkouts with Checkout Extensibility and Functions. See our Shopify development service or message us.
