Shopify retired checkout.liquid, the old way of editing checkout pages directly, in favor of checkout extensibility: fixed insertion points where an app-built UI extension can add content, plus Shopify Functions for custom logic behind discounts, shipping rates, and payment options. Basic UI extensions work on every plan. The deepest customization and several Functions use cases generally require Shopify Plus.
There's no more editing a checkout.liquid template directly. Shopify phased that out in favor of checkout extensibility: a set of defined slots in the checkout flow, above the line items, below the shipping method, on the thank-you page, and others, where an app-built UI extension can add content. You don't touch raw checkout code; you build or install an extension that renders in one of those slots.
Shopify Functions is the piece that handles logic rather than visuals. A function written against Shopify's Functions API can change which discounts apply, which shipping rates show up, which payment or delivery methods are available, all computed server-side based on rules you define. It's how merchants get custom discount logic or shipping rules that Shopify's standard settings don't offer out of the box.
The catch is plan tier. Checkout UI extensions are broadly available, but the deepest customization, full checkout branding beyond colors and logos, custom validation rules, and several Functions use cases, is reserved for Shopify Plus. If you're on a standard plan and hit a wall, that's usually why.
Even on Plus, building a checkout extension or a Function means working in Shopify's CLI and extension framework, not dragging a block in the theme editor. It's development work, and the rules around what each checkout slot can and can't contain are specific enough that a lot of first attempts get rejected or just don't render where expected. Getting a custom checkout requirement right, a required field that only appears for certain product types, or a shipping rate based on a calculation checkout doesn't natively support, usually takes someone who's built one before.
A checkout UI extension that adds a required field, a resale license number, a delivery instruction, a gift message, exactly where it needs to show up, with validation that blocks checkout until it's filled in correctly.
A Shopify Function that calculates a shipping rate or applies a discount based on rules Shopify's built-in settings can't express, tiered by product mix, customer segment, or order history.
Describe the checkout requirement. We'll scope whether it's a Functions build, a plan-tier issue, or both, and what it actually takes.
Describe what you're trying to add or change, a field, a shipping rule, a discount condition. Checkout is one corner of what a Shopify store needs automated. Wherever else the manual work is piling up in your business is worth the same conversation.
Let's talk →No. Shopify has retired checkout.liquid for all stores. Customization now goes through checkout extensibility, where apps add UI at defined slots in the checkout flow, and Shopify Functions, which handles logic like custom discounts and shipping rates.
Not for everything. Basic checkout UI extensions are available on every plan. Deeper customization, full branding control, custom validation, and several Shopify Functions use cases, is limited to Shopify Plus.
Server-side logic that changes what checkout shows: which discounts apply, which shipping rates are offered, which payment or delivery methods are available. They're written against Shopify's Functions API and are the mechanism behind most custom checkout rules that go beyond Shopify's default settings.
The current framework for customizing Shopify checkout. Instead of editing a template directly, apps build extensions that render at fixed points in the checkout flow, defined by Shopify, not the merchant's own code.