How to Modify checkout.liquid in Shopify Plus (2026)

Key takeaways

• checkout.liquid no longer runs on any store: Shopify turned it off for checkout steps on August 13, 2024 and for Thank you / Order status pages on August 28, 2025.
• Plus stores customize checkout with checkout UI extensions and Shopify Functions.
• Every deprecation deadline has passed, and Plus stores that had not upgraded were moved to Checkout Extensibility automatically starting January 2026.
• Additional scripts were turned off for Plus stores on August 28, 2025 and for other plans on August 26, 2026.

You can no longer modify checkout.liquid in Shopify Plus. Shopify turned it off for the Information, Shipping and Payment steps on August 13, 2024, and for the Thank you and Order status pages on August 28, 2025. Plus stores now customize checkout with checkout UI extensions and Shopify Functions. The legacy examples below show what checkout.liquid used to do, so you can read old customizations and rebuild them on the new system.

What happened to checkout.liquid?

Shopify turned off checkout.liquid for the Information, Shipping, and Payment steps on August 13, 2024, and for the Thank you and Order status pages on August 28, 2025. All checkout customizations now run on Checkout Extensibility, not checkout.liquid.

Every deadline has passed, and Plus stores that had not upgraded were moved over automatically starting January 2026. Treat the code on this page as a reference for understanding legacy customizations, not as a build guide. Our checkout.liquid to checkout extensions migration guide covers the move step by step.

Who could access checkout.liquid?

Only Shopify Plus merchants. On Plus stores, the file sat in the theme code editor (the three-dot menu (…) next to your theme, then Edit code) under the layout/ folder. It never appeared for Basic, Shopify, or Advanced plan stores, which could only change the checkout through Settings → Checkout (limited visual settings) and the Additional scripts field. Editing checkout.liquid no longer changes the checkout on any plan.

What checkout.liquid was used for

Adding trust content

Stores used checkout.liquid to add trust signals where purchase anxiety peaks, for example:

<!-- Add to the checkout header or sidebar area -->
<div class="checkout-trust-bar">
  <span>🔒 Secure checkout</span>
  <span>Free returns on all orders</span>
  <span>Delivery in 2-3 business days</span>
</div>

Custom content could only go in the zones the template exposed around Shopify’s own checkout markup. Today the same content goes in a checkout UI extension or an app block placed in the checkout editor.

Custom checkout header and footer

By default, the checkout inherited a simplified version of the theme’s header (logo only) and a generic footer. In checkout.liquid, Plus stores added brand elements, custom navigation links, and footer content. Today, logo, colors and fonts are set in the checkout editor’s branding settings, and extra header or footer content goes in a checkout UI extension.

Adding custom CSS

<!-- In checkout.liquid <head> section -->
<style>
  .checkout-trust-bar {
    display: flex;
    gap: 24px;
    justify-content: center;
    padding: 12px;
    background: #f5f5f5;
    font-size: 12px;
  }
</style>

Checkout Extensibility doesn’t accept custom CSS. Styling is limited to the branding settings, so CSS like this has no direct replacement. For the trust content on the other side of checkout, see Add Trust Badges to Shopify Checkout.

Checkout Extensibility: the new approach

Checkout Extensibility is Shopify’s current checkout customization platform. It consists of:

Checkout UI Extensions: React-based components that render inside specific locations in the checkout. They do the job checkout.liquid HTML used to do, but are managed through Shopify’s Admin → Settings → Checkout → Customize.

Shopify Functions: server-side logic that runs during checkout processing (discount logic, payment customization, delivery customization).

What Checkout Extensibility can do

• Add custom UI blocks to the checkout: information banner, custom text, form fields
• Add upsell offers in the checkout sidebar
• Implement custom discount logic
• Customize payment method display
• Add post-purchase upsell pages

Accessing Checkout Extensibility

Settings → Checkout → Customize opens the visual checkout editor. You can move elements, toggle sections, and add extension blocks here.

For building custom UI extensions, you need a developer and Shopify’s CLI to deploy extension code. This is more involved than editing checkout.liquid was, but it is the supported approach. For changing the wording of checkout fields, see Change Checkout Field Labels in Shopify.

What Fudge does and doesn’t do for checkout

Fudge, the AI operator for Shopify stores, builds and modifies pages within your Shopify theme: product pages, landing pages, collection pages, cart, custom sections. It doesn’t edit checkout. Checkout customization is a separate system from the theme, governed by Checkout Extensibility.

For pre-checkout conversion elements (sticky ATC bars, upsells on product pages, cart drawer customization, countdown timers, trust badges), Fudge is the right tool. Describe what you want to its store editor, and Fudge generates the code as a draft for you to approve. The one part of its work that reaches checkout is discounts: Fudge creates offers with Shopify’s own discounts, so they apply at checkout without any checkout code.

For checkout-specific customization on Plus plans, use checkout UI extensions and Shopify Functions.

Thank you page / Order status page

The order confirmation (Thank you) and Order status pages used to accept custom HTML and JavaScript in:

Settings → Checkout → Order status page → Additional scripts

Additional scripts were turned off for Plus stores on August 28, 2025 and for other plans on August 26, 2026. Use custom pixels (Settings → Customer events) for tracking and app blocks in the checkout editor for content. Common historical uses of the field were:

• Conversion tracking pixels (for platforms not using Customer Events)
• Post-purchase survey embeds
• Referral program prompts
• Custom thank-you messages

With Checkout Extensibility, Shopify has rebuilt the Thank you page as a proper extension target with a visual editor at Settings → Checkout → Customize.

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