Shopify Plus Development for Checkout, B2B and Multi-Store Brands
Shopify Plus development is the engineering work that only makes sense once a store is on Plus: a checkout built with checkout extensibility, discount and shipping logic moved from Shopify Scripts to Shopify Functions, wholesale selling through native B2B, and a group of expansion stores run from one organisation. We do this work for brands already on Plus, brands about to upgrade, and brands moving to Plus from another platform. You get a scoped plan, a staged build you review before launch, and a Plus setup your team can run without a developer on call for every change.
This page sits inside our wider Shopify store build service, which covers new stores on every plan. Here we go deep on the features and constraints that are specific to Plus.
What a Shopify Plus agency actually builds
Plus is not a different platform. It is Shopify with extra surfaces you can customise, higher API limits, and organisation-level tools for running more than one store. A Shopify Plus agency earns its fee on those extra surfaces, because that is where most in-house teams and general theme developers get stuck.
In practice, Plus work falls into six areas:
| Area | What we build or configure | Typical trigger |
|---|---|---|
| Checkout | Checkout branding, checkout UI extensions, web pixels for tracking | Upgrading from checkout.liquid, or a checkout that looks off-brand |
| Pricing and promotion logic | Shopify Functions for discounts, delivery and payment rules | Shopify Scripts still running, or promotions an app cannot express |
| B2B | Companies, locations, catalogs, price lists, payment terms | Wholesale orders handled by email or a separate platform |
| Multi-store | Expansion stores, shared data, organisation users | New region, new brand, or a separate wholesale store |
| Operations | Shopify Flow workflows, Launchpad events | Manual tagging, sale launches run by hand at midnight |
| Migration | Moving to Plus from another platform or plan | Adobe Commerce, Salesforce Commerce Cloud, BigCommerce or WooCommerce stores |
Checkout extensibility and checkout branding
Checkout extensibility replaced checkout.liquid as the way to customise Shopify checkout. If your store still carries old checkout.liquid edits or "additional scripts" on the order status page, those need rebuilding in the new model. The good news is that the new model is upgrade-safe: extensions keep working when Shopify ships checkout changes.
What we handle in a checkout project:
- Checkout branding. Colours, typography, corner radius, header and footer, set in the checkout editor and, where the editor is not enough, through the Checkout Branding API in the Admin GraphQL API.
- Checkout UI extensions. On Plus, extensions can sit inside the information, shipping and payment steps, not only on the thank you and order status pages. Common builds: delivery date pickers, gift messages, B2B purchase order fields, loyalty point balances, custom trust or policy content.
- Tracking. Old order status scripts become web pixels through customer events, so your GA4, Meta and other tags still fire on purchase.
- Upgrade audit. We list every customisation in the current checkout, decide which ones still earn their place, and rebuild only those.
We build the extension. Deciding which checkout changes actually lift completion rate is conversion work, which our checkout conversion team owns and tests.
Moving from Shopify Scripts to Shopify Functions
Shopify Scripts ran Ruby code in the Script Editor app to change line item prices, shipping rates and payment methods. Shopify Functions are the replacement path. They run as part of an app, on Shopify's infrastructure, and cover discounts, delivery customisation, payment customisation, cart and checkout validation, and cart transforms for bundles.
A Scripts migration is rarely a line-by-line port. Scripts often accumulated years of edge cases: a staff discount that stacks with one promo but not another, a shipping rate hidden for PO boxes, a payment method removed for high-risk countries. Our process:
- Export every active script and write out, in plain English, what each branch does.
- Check which behaviours are now covered by native discounts or settings, so no code is needed.
- Build the remaining logic as Functions inside a custom app installed only on your store. On Plus, custom apps can run Functions, which is what makes store-specific logic possible.
- Run both side by side on a development store with real cart scenarios before the switch.
When a Function becomes part of a larger feature, like a product configurator or a bundle builder, it moves into our custom Shopify app and Functions builds.
B2B on Shopify Plus
Native B2B lets one store sell to consumers and trade buyers without a separate wholesale platform. We set up:
- Companies and locations, with buyers attached to each location and their own shipping and billing addresses.
- Catalogs and price lists per company or group, including fixed prices and percentage adjustments.
- Quantity rules and volume pricing so case packs and minimum order quantities are enforced at the cart.
- Payment terms such as net terms, plus the option to require order review before a B2B order is confirmed.
- Customer accounts so buyers can reorder, check order history and manage their locations.
The big design decision is blended versus separate. A blended store serves B2B buyers from the same storefront, with prices and catalogs switching on login. A separate B2B expansion store gives wholesale its own theme and navigation. Blended is simpler to run. Separate is cleaner when wholesale buyers need a very different experience, like a quick-order form for hundreds of SKUs. We help you choose based on your catalogue and how your trade customers actually order.
If your trade orders need to land in an ERP or accounting system, that connection is scoped with our ERP and back-office integration service.
Expansion stores and organisation admin
Plus lets you run expansion stores under one organisation. Brands use them for a new region with its own catalogue, a second brand, a wholesale store, or an outlet. Before adding a store, we check whether Shopify Markets inside one store already covers the need. Markets handles currencies, languages, domains or subfolders, and local pricing without duplicating products, which is often less work to maintain.
When separate stores are the right call, we set up:
- The organisation admin, with users added once and given access store by store.
- Staff roles and permissions that match real jobs: warehouse staff see orders, marketing sees themes and discounts, finance sees payouts.
- A shared theme codebase through Shopify CLI and GitHub, so a fix ships to every store rather than being copied by hand.
- A product data plan, so the same SKU does not drift between stores.
How those stores are indexed and targeted in search is a separate question, covered by our international and enterprise SEO for Plus.
Shopify Flow and Launchpad setup
Shopify Flow is where Plus stores remove repeat admin work: tagging high-value orders, holding risky ones, alerting the warehouse about pre-orders, hiding products when stock hits zero. We build the workflows, test them against past orders, and document what each one does so your team can edit them later. Larger fulfilment and order routing projects go to our order processing automation team.
Launchpad schedules sales events: a theme swap, discount activation, product publishing and price changes that go live and roll back at set times. For a flash sale or product drop, that means nobody is editing products by hand at midnight.
Migrating to Shopify Plus
There are two kinds of Plus migration.
Upgrading from another Shopify plan. The store already works. The job is to switch on what Plus adds: move to checkout extensibility, replace any script-like app workarounds with Functions, set up the organisation, and configure B2B or expansion stores if they are part of the reason you upgraded.
Replatforming from another system. Adobe Commerce (Magento), Salesforce Commerce Cloud, BigCommerce, WooCommerce and custom builds all store data differently. We map products and variants, customers, order history, gift cards, B2B price rules and content into Shopify's model. Some things do not transfer directly: customer passwords are one example, so we plan the account activation approach up front. Custom checkout logic on the old platform becomes Functions and checkout UI extensions.
Protecting search traffic, URL structures and redirects during a platform move is handled with our redesign and replatforming service, which runs alongside the Plus build so rankings and revenue are watched through the switch.
How a Plus project runs
We follow the same four steps on every engagement, with the detail shaped to Plus. The general version is on our process page.
- Audit and baseline. We review your current checkout customisations, active scripts, apps doing work that Plus now handles natively, B2B workflow, and store structure. You get a written list of findings and a baseline of checkout completion, speed and key admin processes.
- Strategy and scope. We rank the work by impact and risk, for example Scripts migration before checkout styling if a deadline is involved. You agree a fixed scope and timeline before any build starts.
- Build and fix. Theme work happens on a duplicated theme. Functions and checkout extensions are built in a development store or tested on a preview. You review every change on a preview link, and nothing reaches the live store without your sign-off.
- Launch and track. Approved changes go live in a planned window. Ongoing engagements get a private client portal, monthly reporting and a monthly call to agree next steps.
Timelines and pricing
Plus projects are fixed project fees, scoped after a discovery call and the audit. There is no public rate card because a single checkout extension and a full replatform with B2B are very different jobs. See our pricing model for how scoping works.
Typical ranges depend heavily on store size, the number of scripts and integrations, and how fast decisions are made on your side:
| Project type | Typical range (depends on scope) |
|---|---|
| Checkout extensibility upgrade | A few weeks |
| Scripts to Functions migration | Two to six weeks |
| B2B setup on an existing store | Three to eight weeks |
| Replatform to Plus | Two to six months |
If Shopify Scripts are still running on your store, that migration is usually the first thing to scope. Book a Scripts to Functions review and we will list every script and what it needs to become.
Who this is for
- Brands on Plus that still run checkout.liquid edits or Shopify Scripts and need a clean move to the current model.
- Stores upgrading to Plus that want the upgrade to pay for itself through B2B, Functions or expansion stores, not just a higher plan.
- Wholesale-heavy brands that want trade orders out of email and spreadsheets.
- Teams on Adobe Commerce or Salesforce Commerce Cloud looking for a platform with lower maintenance.
If you are not on Plus and do not need these features, a standard build is usually the better fit. Our team can also help plan the storefront experience itself through UX and visual design for Shopify.
Why work with us
We work only on Shopify and Shopify Plus, so our time goes into the platform's current tools: checkout extensibility, Functions, B2B, Flow and the Admin GraphQL API. Every build is staged and reviewed by you before it goes live. You get documentation for each Function, extension and workflow, so your next developer, in-house or external, can pick it up.
Frequently asked questions
Every plan can use the checkout editor and extensions on the thank you and order status pages. Plus adds checkout UI extensions inside the information, shipping and payment steps and deeper styling through the Checkout Branding API.
Shopify Functions are the replacement path for Shopify Scripts, so your script logic needs rebuilding as Functions. We document what each script does, drop what native settings now cover, and rebuild the rest in a custom app tested before the switch.
Most brands start blended, in the main store, because it is simpler to run. A separate store makes sense when trade buyers need a very different catalogue, theme or ordering flow.
A replatform to Plus usually takes two to six months, depending on catalogue size, integrations and data quality. An upgrade from another Shopify plan is faster because the store already runs on Shopify.
Each project is a fixed fee quoted after a discovery call and an audit of your store. We do not publish a rate card, because scope varies so much between a single checkout extension and a full replatform.
Yes. We often take the Plus-specific parts, such as Functions, checkout extensions or B2B, while your team keeps the theme. We work through Shopify CLI and GitHub so changes are reviewable.
We plan redirects and keep URLs stable as part of the migration. Ongoing search work for large or international Plus stores sits with our Plus SEO team.
Related services
- Checkout conversion optimisationtests which checkout changes improve completion before we build them.
- Custom apps and Functions beyond Plus featuresconfigurators, bundles and data models that go past standard Plus setup.
- Connecting Shopify Plus to your ERP or 3PLsyncs orders, stock and B2B prices with your back office.
- Automated order routing and taggingextends Flow into fulfilment and exceptions handling.
- Plus SEO for large catalogues and Marketskeeps expansion stores and international setups indexable.
Talk to a Shopify Plus developer
Tell us what is holding your Plus store back, whether that is Scripts, checkout, B2B or a migration. We start with a free audit of your current setup and send you the findings in writing. Talk to a Shopify Plus developer to book the discovery call.