Shopify Plus Implementation: What the First 90 Days Involve

A Shopify Plus implementation is a sequence of decisions, builds and sign-offs, and the order matters more than most quotes suggest. This post lays out the first 90 days week by week, so you know what you are signing up for and what your own team has to do. We map Seventh Triangle's seven-step process onto the plan. Treat the dates as a planning model: scope, integrations and the number of regions can all stretch it.

A Shopify Plus Implementation Timeline, Week by Week

Each phase matches one or two of our seven steps: initial chat, research and plan, present, develop, revise and refine, test, and deliver.

Weeks 1–2: Onboarding and Scoping

Shopify Plus onboarding starts with a short call and a research pass: your catalogue, current platform, order volumes and every system that touches an order. The output is a written scope and a named owner on your side for each area, such as finance, operations, merchandising and IT. A missing owner can hold up a phase as easily as a technical problem. If part of your scope is a brand-new store rather than a migration, Shopify store setup beyond the basics covers that side separately.

Weeks 3–4: Presenting the Plan and Fixing the Structure

We present the architecture and ask for sign-off before building. The big structural call is where each region lives. Shopify Plus expansion stores, up to nine alongside the main store, come at no extra cost, and they suit separate regions, B2B storefronts or product lines. A new market can also sit inside one store, so decide based on who manages the catalogue, pricing, and fulfilment.

A regional rollout shows why this matters. FNP's Shopify Plus build for Saudi Arabia needed an Arabic, right-to-left interface and a headless front end on Hydrogen. Choices like those shape everything built afterwards.

Weeks 5–6: Integrations and Checkout

Build starts with the systems that move money and stock. Typical Shopify Plus integrations cover ERP, inventory, shipping and payment tools. Each needs a test plan and agreed failure behaviour, for example, what happens when the ERP is unreachable. That is the work behind Shopify system integrations, and it deserves the most test time.

Checkout comes next. checkout. Liquid is no longer supported on Plus, so customisation now runs through Shopify Plus checkout extensibility: checkout UI extensions and branding controls. Custom checkout UI extensions are available only on Plus.

Weeks 7–8: B2B and Pricing Logic

A Shopify Plus B2B setup covers companies and locations, catalogues, payment terms and quantity rules. Net terms, quantity rules and volume pricing are available on every plan. Unlimited B2B market catalogues, direct company catalogues, deposits and partial payments need Plus.

Custom discount, shipping, or payment logic now runs on Shopify Functions. Shopify Scripts stopped executing on 30 June 2026, so any rule that once lived in a script has to be rebuilt as a Function.

Weeks 9–10: Revise and Refine

After each milestone, you review a working build, not a mock-up, and feedback goes in before the next phase starts. The Shopify Plus project plan should log every change request against scope, owner and date, so nothing quietly stretches the timeline. How we manage projects covers the status meetings and stakeholder reports behind that.

Weeks 11–12: Testing

Test with real order scenarios on a staging or development store: discounts, tax, shipping rates, B2B orders, refunds and integration failures. Then work through a Shopify Plus go-live checklist:

• Redirects and URL mapping checked

• Payment gateways and tax settings confirmed in live mode

• Integrations tested with live credentials

• Staff accounts and permissions reviewed

• Analytics, pixels and Shopify Flow automations verified

• Rollback owner and rollback steps agreed

Week 13: Go-Live and Handover

The Shopify Plus launch plan sets the cutover date and the content freeze, names who watches what once the store is live, and says who has the authority to roll back. Plan support for after launch too, because live traffic finds edge cases that staging does not.

Before You Sign: What to Ask Your Shopify Plus Agency

• Who owns each phase on their side, and who owns it on yours?

• How are change requests logged and priced once the plan is signed off?

• Which integrations are in scope, and what happens when one fails?

• What are the acceptance criteria for testing, and who approves them?

• What support applies after launch, and for how long?

If you'd like this plan mapped to your own scope, we're happy to walk through it with you.

FAQs (Frequently Asked Questions)

1. How long does a Shopify Plus implementation take?

There is no single fixed duration. A focused scope, with one store and a few integrations, can be planned in about 90 days, as above. Heavy ERP work, several regions or a large B2B catalogue can push it past that. Ask any agency for a week-by-week plan tied to your scope, not a headline number.

2. What is checkout extensibility on Shopify Plus?

It is Shopify's way of customising checkout without editing checkout code. It replaced checkout.liquid, which Shopify says was sunset on 28 August 2025. Plus, stores can use checkout UI extensions, advanced branding controls and custom apps at checkout, while some prebuilt apps work on other plans too.

3. What are Shopify Functions, and when would a store need them?

Shopify Functions let a developer change how checkout rules behave: which discount applies, which delivery rates show, and which payment methods appear. Shopify hosts and runs the code for you. If an app from the Shopify App Store already covers your rule, you probably don’t need one of your own. Writing custom Functions is limited to Plus.

4. Do I still need to get off Shopify scripts?

Yes, if any of your checkout rules lived in scripts. Since 15 April 2026, you could no longer edit or publish them, and on 30 June 2026 they stopped running altogether. Shopify’s Scripts customisations report lists what you had and shows which rules can move to Functions or to a public app.

5. Is there a limit on how many stores I can run with Shopify Plus?

A Plus organisation can have up to ten stores on its contract at no additional cost: the main store and nine expansion stores. Staging stores do not count toward that limit. Use extra stores when a region, product line or wholesale audience needs its own setup.

6. Which B2B features need Shopify Plus?

Unlimited B2B market catalogues, direct company catalogue assignment, deposits, partial payments and payment requests per fulfilment are Plus-only. Companies, net payment terms, quantity rules and volume pricing are available on all plans. Check Shopify's B2B plan comparison before scoping, because plan features change.

7. What usually delays a Shopify Plus go-live?

Three things come up most: unclear owners on the client side, integrations built late, and checkout or discount logic tested too close to launch. A written plan with sign-offs per phase and early integration testing reduces all three.