Legacy vs New Customer Accounts on Shopify: should you migrate?

If someone told you your store is on a "legacy Shopify architecture" and needs to migrate to "Next-Gen", the first thing to clarify is what they actually mean. The term gets thrown around loosely and usually conflates two very different things.

What "legacy" actually means today

There are two distinct concepts that often get grouped under the same label.

• The first is checkout: Shopify deprecated checkout.liquid and migrated all stores to Checkout Extensibility. That migration is done. Every active Shopify store today is already on the new checkout architecture. If someone is telling you that you need to migrate your checkout to "Next-Gen", that work either already happened or the person doesn't know what they're talking about.
• The second is Customer Accounts: This is the actual remaining legacy decision in Shopify today. Legacy Customer Accounts use email and password. New Customer Accounts use passwordless login: a one-time code sent via email. This is where the real "legacy vs next-gen" conversation lives in 2025 and 2026.

So if your store is on "legacy architecture", the honest translation is: you're using the old customer account system with email and password login. That's it. Your checkout is fine.

Should you migrate to New Customer Accounts?

Maybe. It depends on what your store does with customer accounts and what you have built around them.

The UX case for migrating is real. Passwordless login reduces friction, existing customers don't need to re-register, and the new experience is generally cleaner. Shopify is clearly pushing in this direction and the new system will keep getting investment.

The case for deferring is also real. This is not a low-impact migration. Several things break or need to be rebuilt:

1. Liquid customizations: Any Liquid customizations on /account, /account/orders, or /account/login won't carry over. They need to be rebuilt using Customer Account UI Extensions. If you have a custom account dashboard, loyalty integrations, or any bespoke UI in the account section, that work needs to be scoped and redone.
2. Flow automations: Shopify Flow automations based on legacy account creation or login events won't migrate automatically. Every related Flow needs to be rebuilt using the new event model.
3. Multipass SSO: If you use Multipass for SSO, that's not supported on New Customer Accounts. You'll need a custom identity provider implementation, which is a non-trivial piece of work.

What about your apps?

Most major apps handle both systems without issues. ReCharge, Rebuy, Gorgias, and Okendo don't require New Customer Accounts to function. None of them are a strong reason to migrate urgently. Check your specific app stack, but in most cases vendor compatibility isn't the forcing function.

When to migrate

Migrate when you have a clear reason: a feature you actually need that requires New Customer Accounts, or a dedicated window to do it properly without coupling it to other work.

Don't migrate because an app recommended it, because someone called your store "legacy", or because you want to stay current. Those aren't reasons, they're noise.

If you do migrate, treat it as a standalone initiative. Design any ongoing PDP, cart, or checkout work to be customer-account-agnostic so you're not coupling unrelated rebuilds. The migration itself needs its own scope, QA, and sequencing. The risks are real: broken account UI, broken automations, and authentication complexity if SSO is involved.

The short version

Your checkout is not legacy. The only remaining legacy decision is Customer Accounts. Migrating has real UX benefits but meaningful implementation cost. Defer unless you have a specific reason to move now, and when you do move, do it as a dedicated initiative with proper planning.