The Shopify Migration Checklist That Covers What's Actually Changed in 2026

By Milan Dhameliya · · 9 min read

A migration checklist that only covers exporting data, mapping 301 redirects, and testing checkout is the same one agencies have been recycling since 2019 — and it leaves out four platform changes that can break a store on launch day: Checkout Extensibility, the mandatory new Customer Accounts system, Managed Markets' new duties default, and the Collections model that changed in July 2026. We checked five of the top-ranking migration checklists and Shopify's own official one. None of them mention any of the four.

A Shopify migration checklist that only covers exporting your old catalog, mapping 301 redirects, and testing checkout is the same checklist agencies have been copying since around 2019 — and in 2026 it skips four platform changes that can break a freshly migrated store on launch day. Checkout can no longer be hand-coded the way it could on most other platforms. New stores can't choose the old customer accounts system even if a tutorial tells them to. International duties can get set for you without anyone deciding it. And collections built with an outdated tool might not carry the features you assumed they would.

We checked five of the currently top-ranking "Shopify migration checklist" articles and Shopify's own official one. Not one of them mentions Checkout Extensibility. Not one mentions Managed Markets' duties change. The official Shopify checklist's only comment on customer accounts is a single line about passwords not transferring, and its only comment on collections is "organize your products into collections," with no mention of what changed underneath that phrase this year.

What the standard checklist still gets right

None of this is a criticism of the basics — get those right first. Export products, customers, and order history from your current platform; back up media separately, since image exports are where most migration tools cut corners. Benchmark your current rankings and traffic before you touch anything, because you can't measure SEO damage against a baseline you didn't record. Map every URL that currently ranks to its Shopify equivalent and set up 301 redirects under Online Store > Navigation > URL Redirects before launch, not after someone notices traffic dropped. Place real test orders, including a refund and a partial fulfillment, before you remove the storefront password. That part of the generic checklist is correct and worth following exactly as written. What it misses is everything below.

Four things that changed on Shopify itself, not on your old platform

Our own complete guide to migrating from WooCommerce or Magento covers the data-migration and theme-recreation mechanics in more depth than this post will — read that one for the step-by-step. What it was published before, in February 2026, is everything that follows, because all four of these changed on Shopify's side after that guide went live.

Checkout: you can't hand-code it the way you could before

If your current platform lets a developer edit the checkout page directly — a common setup on Magento, and achievable on WooCommerce with the right plugin — the instinct on a new Shopify store is to look for the equivalent file to edit. There isn't one. Shopify checkout no longer accepts arbitrary code: customer-facing checkout changes go through Checkout UI Extensions, and logic that changes price, shipping, or payment methods goes through Shopify Functions. Checkout Extensibility replaced the old checkout.liquid model, and Shopify Scripts — the old way Plus stores wrote custom discount and shipping logic — stopped executing entirely on June 30, 2026, after running alongside extensions during a transition window.

The part that catches new-to-Shopify teams specifically: on plans below Plus, extension-based checkout customization is more limited than the marketing copy implies. If your migration plan assumes you'll rebuild a fully custom checkout step (a gift-note field, a delivery-date picker, a loyalty-points redemption box) the way you had it on your old platform, confirm which plan you're actually launching on first — our checkout extensibility migration plan covers what UI Extensions and Functions can and can't do, and what to fall back to when the answer is "not on this plan."

Who can skip this section: if your old checkout was already close to Shopify's default — standard fields, no custom logic, no per-item gift options — there's nothing to rebuild and this trap doesn't apply to you.

Customer accounts: there's no legacy option to accidentally build on

Plenty of still-circulating tutorials for setting up a Shopify store describe customizing the login popup, adding custom registration fields, or branding the account page — all workflows that belonged to legacy customer accounts, which Shopify deprecated on February 26, 2026. New stores can no longer select legacy accounts at all; every new store is on the current Customer Accounts framework, which uses passwordless, one-time-code sign-in and a different customization model (Customer Account UI extensions instead of theme-level popup edits). If you're migrating and someone on the project is following an older guide, they'll be looking for admin settings that no longer exist on a new store, not settings that need updating — our rebuild guide covers what actually replaced the login popup, custom fields, and order-page branding those older tutorials describe.

One migration-specific detail worth confirming early: password data does not transfer from your old platform, regardless of which accounts system you land on, so every customer re-authenticates on first login after launch. Plan the "reset your password" or "verify your email" communication before launch day, not as a reaction to support tickets afterward.

International: Managed Markets may have already picked your duties setting

If part of the migration plan is selling into new countries, or you're already using Shopify Managed Markets for existing international sales, know that every market still shipping delivered-duty-unpaid switched to delivered-duty-paid automatically on August 24, 2026, with no setup required and no error thrown if nobody acted on it. That's a Managed Markets–specific change — a narrower product than the plain duties toggle in Settings > Markets — so it may not apply to your setup at all, but it's exactly the kind of thing worth confirming deliberately during migration rather than discovering after your first international order comes in priced differently than the customer expected. It's also the sort of setting a generic migration checklist has no reason to mention, because it isn't about migrating data — it's about a default Shopify changed underneath a product you might already be using.

Collections: confirm your import tool was actually built for the current model

Shopify's collections model changed substantially in GraphQL Admin API version 2026-07: a collection can now combine multiple sources — automated conditions, hand-picked products, other collections, and app-fed sources — and target specific variants instead of only whole products. That's a genuine merchandising upgrade if you need it. The part worth checking before you rebuild your collection structure: Shopify's own developer changelog states that collections using the new multi-source or variant-targeting features are filtered out of any query still running a pre-2026-07 API version. That isn't corruption and it isn't an error message — a migration app, a custom import script, or a sitemap tool that hasn't been updated to 2026-07 simply won't see those collections in whatever list it's building. If you're using a migration or import app you haven't checked the changelog of recently, confirm it's been updated before you build your collection structure around features it might not even know exist yet.

For most stores rebuilding collections from scratch during a migration, this doesn't change what you do day to day — you'll still set up conditions and manual picks the way collection-setup guides describe. It matters specifically if a developer is scripting collection creation via the Admin API, or if an app promises "automatic collection sync" and you haven't confirmed which API version it's calling.

The step that isn't on any checklist: audit the catalog after launch, not just before

Migrated catalogs are exactly where catalog-hygiene problems tend to concentrate, and not because anyone was careless — bulk imports are how they happen at scale. Our own breakdown of WooCommerce-to-Shopify product import methods found that a bare CSV import silently drops anything past three variant options, leaves WordPress shortcodes sitting raw in product descriptions, and can reissue every variant ID on re-import — quietly breaking any subscription or loyalty app that was keyed to the old ones. None of that throws an error in Shopify's admin. The product page previews fine either way.

That's the same pattern behind the duplicate descriptions, missing alt text, and unpublished-but-still-indexed products we find across the store scans in our own corpus — problems that look fine in the admin and only show up when something actually checks the storefront output. If you migrated a catalog in the last few months and haven't run a check since, our free store scanner looks for exactly these gaps and takes about two minutes against a live URL.

Who can skip most of this

If you're migrating a single-market store with a standard checkout, no custom login flow, no international duties setup, and a catalog under a few hundred SKUs on a theme you're building fresh rather than importing collection structure into — most of the four traps above simply don't have anything to bite. Follow the generic checklist, get the redirects and the checkout test right, and you'll be fine. This list matters most for stores with any checkout customization beyond default fields, a customer-accounts-dependent membership or loyalty flow, active international selling through Managed Markets, or a developer scripting collection setup instead of building it by hand in the admin — that's where a checklist written before 2026 quietly stops being accurate. If you're not sure which category your migration falls into, that's worth a conversation before launch rather than after — this is the kind of platform migration work we do directly.

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