Checkout Extensibility, Functions and B2B: Where Shopify Plus Differs From Advanced

If your team asked for a checkout change and was told “that needs Shopify Plus,” the answer was probably right two years ago. Since then Shopify has replaced checkout.liquid with Checkout Extensibility, switched off Shopify Scripts and moved most B2B features onto its lower plans. In 2026 the gap between Shopify Plus vs Advanced is narrower than most comparison pages suggest, and much more specific.

This guide is for brands on Grow or Advanced that keep hitting the same limits. Typical examples are a checkout step they can’t change, discount logic no app handles, wholesale pricing that doesn’t fit into three catalogs, or a new market that needs its own store.

Below we cover what Checkout Extensibility and Shopify Functions do on Plus, where native B2B stops on lower plans, what Flow and Launchpad add, and when the upgrade doesn’t pay off yet. Plan details come from Shopify’s own documentation and changelog as of September 2026, linked in each section.

For the broader business case, including team size, support and timing, see our overview of what Shopify Plus development unlocks for growing brands. This piece goes one level deeper into the technical side.

Shopify Plus vs Advanced: What You Pay For Beyond Higher Limits

The Plus fee mainly buys access to checkout steps, custom logic and B2B tools that stay closed on other plans. Higher API limits come with the package and matter to a smaller group of stores.

According to Shopify’s Plus pricing page, Plus costs $2,300 a month on a three-year term or $2,500 a month on a one-year term for standard setups and integrations. More complex, higher-volume businesses may move to a variable platform fee based on revenue, which Shopify calculates differently for B2B and D2C. Shopify also advises budgeting separately for custom development, themes and apps. In practice, the platform fee is the predictable part of the bill and the build is the variable one.

Here is where the line between Shopify Plus features and lower plans sits today:

Area	Available below Plus	Plus only
Checkout	Extensions on the Thank you and Order status pages; checkout overrides by market on Advanced	Extensions on the Information, Shipping and Payment steps; checkout branding through the API; separate B2B and D2C checkout flows in one store
Shopify Functions	Functions inside public App Store apps	Functions inside custom apps built for your store
B2B	Companies, up to 3 catalogs, net terms, volume pricing	Unlimited catalogs, catalogs assigned to specific companies, deposits, partial payments
Automation	Shopify Flow on every paid plan	Launchpad; Flow tasks from custom partner apps
Stores	Unlimited country markets in one store	Up to 9 expansion stores under one contract
Admin API	100 points/second (200 on Advanced)	1,000 points/second; no daily cap on new variants past 500,000

The API numbers matter in fewer cases than they suggest. Per Shopify’s API limits documentation, limits apply to each app and store pair, so every integration gets its own budget. Bulk operations, which is how most nightly catalog exports run, aren’t rate-limited on any plan. The extra capacity on Plus pays off in two situations: an ERP or PIM that pushes inventory and prices throughout the day, and a catalog past 500,000 variants, where lower plans face a daily cap on new variants.

If most of the right column describes your requirements, here is what a Shopify Plus build with our team involves.

Checkout Extensibility After the checkout.liquid Deadline

Shopify Plus checkout customization now runs entirely through Shopify Checkout Extensibility, and the legacy tools have been switched off.

checkout.liquid is no longer supported on the Information, Shipping and Payment steps. On the Thank you and Order status pages, checkout.liquid and additional scripts were sunset on August 28, 2025. Script tags on those pages were sunset for Plus stores on the same date and for all other plans on August 26, 2026. Shopify Scripts, the Ruby layer Plus merchants used for discount, shipping and payment logic, stopped executing on June 30, 2026.

Shopify’s upgrade guide makes the reason for the move clear. A store that enabled checkout.liquid ran on a frozen copy of checkout that didn’t receive automatic updates, so every customized store missed checkout improvements until someone upgraded it by hand. Under Checkout Extensibility, customizations live in extensions and the checkout itself keeps updating.

That matters because checkout is Shopify’s strongest conversion asset. In a study Shopify commissioned in April 2023 from a Big Three consulting firm, its checkout converted 15% better than competitors on average and up to 36% better.

What each plan can change:

• Checkout UI extensions on the Information, Shipping and Payment steps: Shopify Plus only.
• Extensions on the Thank you and Order status pages: every plan except Starter.
• Checkout branding through the GraphQL Admin API: Shopify Plus only.
• Market overrides (branding, settings and extensions per market in the checkout editor): Advanced and Plus.

Plus stores can also run separate checkout flows for B2B and D2C buyers in the same store and create custom shipping discounts through Checkout Blocks.

What Broke and What Replaced It

How it worked in checkout.liquid	What replaced it
Layout edits and JavaScript that rewrote the page after it loaded	Checkout UI extensions placed at defined points in checkout
Custom CSS inside the checkout layout	Checkout Branding API and the checkout editor
Tracking tags in additional scripts and script tags	Web pixel extensions, available on every plan except Starter
Discount, shipping and payment rules in Shopify Scripts	Shopify Functions
Extra fields captured through checkout attributes	Input fields in UI extensions, with validation that can stop the buyer from moving forward

On Plus today, a typical checkout customization is an offer shown before payment, a PO or gift-message field, a banner for a specific audience, or a field check that blocks invalid data. Each of these is built as an extension rather than a code edit.

Shopify documents one practice that saves a lot of rework later. If checkout needs to differ by market, use native market overrides in the editor instead of rebuilding that logic inside an extension. For regional or B2B rules inside your own extension, base them on the delivery address or the company location, never on the market name.

Shopify Functions: Discounts, Shipping and Payment Logic

Shopify Functions are pieces of custom logic that run inside Shopify’s backend during checkout. They replaced Scripts for discount, shipping and payment rules.

The plan question here is often answered wrong. Any store can use public App Store apps that contain Functions. Plus adds the ability to run custom apps with Functions, meaning logic written for your business alone. The test is simple: if an existing app already covers your discount or shipping rule, you don’t need Plus for it. If no app matches the rule, you do.

Typical jobs for Functions:

• Discounts: a new discount type the admin can’t build, with thresholds and stacking rules. Shopify lists enhanced shipping, order and payment discounts among Shopify Plus features.
• Payment options: hide, rename or reorder payment methods, for example removing a payment method for wholesale buyers.
• Delivery options: hide, rename or reorder delivery methods, for example dropping express shipping for oversized items.
• Validation: block checkout when a rule fails, such as an order maximum for customers without order history.

Functions run in a fixed order during checkout: cart changes first, then discounts, then delivery and payment rules, then validation. A validation rule therefore always sees the final discounted cart, which matters when you design rules that depend on the order total.

Because Functions run inside the purchase flow, a slow one can stop a customer from completing an order, and that shapes how they’re built. Shopify strongly recommends Rust. Functions can’t use randomness or the clock, and data comes in through metafields and cart attributes rather than live calls to your systems.

One practical consequence is that Functions aren’t designed to reprice every line in a large cart. For wholesale price lists Shopify points to B2B catalogs instead, which leads to the next section.

When no app covers the rule, the work is a custom app with its Functions and extensions. That is part of our custom Shopify development work.

Shopify Plus B2B vs Native B2B on Lower Plans

For many wholesale programs, native B2B on a lower plan is now enough. Shopify Plus B2B becomes necessary when pricing is set per customer or when payments involve deposits.

Since April 2, 2026, Basic, Grow and Advanced include foundational B2B at no extra cost, as announced in the Shopify changelog. The full split by plan, per Shopify’s help center:

Feature	Basic / Grow	Advanced	Plus
Companies, locations, net terms, ACH (US), vaulted cards, PO numbers	✔	✔	✔
Quantity rules and price breaks, quick order list, Trade theme	✔	✔	✔
B2B catalogs	Up to 3 across all B2B markets	Up to 3 across all B2B markets	Unlimited
Catalogs assigned directly to a company or location	✘	✘	✔
Deposits, partial payments, payment requests per fulfillment	✘	✘	✔
Contextual checkout and storefront through Markets	✘	✔	✔

Check the three-catalog limit first. It applies across all B2B markets combined, so a distributor, dealer and direct-account tier uses the whole allowance before you add a second region. Contract pricing for individual companies isn’t available below Plus at all. On lower plans, B2B catalogs also require the store to run on the new Shopify Markets.

Some brands consider a separate wholesale store instead. On Plus, a B2B store is a pre-approved expansion store type: one per contract is included, and buyers must log in. The trade-off is operational. Each store runs independently, so products, inventory and settings don’t sync, and keeping them aligned takes an app or your ERP. Apps are billed per store, and each store needs its own theme license.

A practical rule: if wholesale and retail share one catalog and one inventory pool, native B2B in a single store is simpler and cheaper to run. A separate store makes sense when the wholesale storefront needs a different theme, a different app stack or a different team, and you’re ready to maintain the sync.

Shopify Flow and Launchpad in Practice

Flow now runs on every paid plan, which leaves Launchpad and bot protection as the automation features still reserved for Plus.

Shopify Flow is a free app on Basic, Grow, Advanced and Plus. Tagging high-value orders, routing wholesale orders for review or alerting the team when stock runs low works on any paid plan. The Send HTTP Request action, which connects workflows to external systems, starts on Grow. Plus adds workflow tasks from custom partner apps, so if automation is your main reason to upgrade, check which workflows actually need that capability.

Launchpad is available only on Plus. It schedules events such as sales, product drops and restocks to start and end on their own. Prices change, products publish and a campaign theme can switch in at a set time without anyone in the admin at midnight. Plus also includes bot protection during flash sales and product launches.

For brands that run frequent drops or large seasonal campaigns, Launchpad and bot protection together make a real operational case for Plus. Brands with fixed prices and rare promotions get little from them.

Multi-Store and Markets for International Brands

Every Shopify plan can sell into many countries from one store, so Plus only becomes necessary here when the business needs separate stores.

All plans include an unlimited number of country and region markets in one store. Advanced adds theme customization and checkout overrides by market. Plus adds B2B markets and Checkout Blocks configured per market.

Expansion stores are the Plus-only part. A Plus contract covers up to ten stores at no additional platform cost: one main store and nine expansion stores, with staging stores not counted. Brands that need more contact Shopify. The rules are strict. An expansion store must be an extension of the main brand, with the same name and the same type of goods. A second brand needs a multi-brand agreement, where each brand has its own Plus subscription.

We saw this trade-off with Meroda Cosmetics, a Dutch beauty brand selling across the EU, the UK and the US. When we took over, the brand ran nine separate Shopify Plus stores. Several of those markets didn’t need a store of their own, so we consolidated the setup to five stores and moved the rest into Shopify Markets. The largest store now runs 27 markets, and the team maintains four fewer stores.

The five that remain needed custom work Shopify doesn’t provide between stores: alternate links and region routing that connect stores which can’t see each other. Read the full Meroda Cosmetics case.

The same independence rule applies as in the B2B section: each expansion store has its own data, apps and theme license. Use Markets while one team can run all countries from one catalog, and add expansion stores when a region needs its own inventory, apps or operating team.

When Is Advanced Enough Instead of Plus?

Advanced is enough when every item on your requirements list can be built on it. Run through these questions before the sales call:

• Checkout: Do you need changes on the Information, Shipping or Payment steps, or would the Thank you and Order status pages be enough?
• Logic: Does an existing App Store app with Functions already cover your discount, shipping or payment rule?
• B2B: Do three catalogs across all B2B markets cover your pricing tiers, and do you sell without deposits or partial payments?
• Integrations: Do your integrations sync in nightly bulk jobs rather than throughout the day, and is your catalog well under 500,000 variants?
• Stores: Can one store with Markets serve every country you sell in?
• Campaigns: Do you run few enough timed sales that scheduling them by hand is manageable?

If most answers are yes, Advanced covers you today and the gap to Plus is mostly platform fee. Many limits that feel like platform limits are storefront limits that a better theme or custom sections can solve.

We compare those paths in Shopify development vs custom Shopify development. If two or more answers are no, especially on checkout or B2B pricing, Plus is likely the cheaper path compared with workarounds.