How to Merge Duplicate Customers in Shopify (One Pair at a Time or in Bulk)

To merge duplicate customers in Shopify, open one of the profiles, choose More actions > Merge customer, pick the duplicate, check the preview and confirm. Shopify moves orders, addresses, tags and notes onto one profile and discards the other. The native tool works on two profiles per merge and can't be undone, so it suits a handful of duplicates. For dozens or hundreds you need a way to find the pairs and merge them in bulk.

This guide covers both: the exact native steps, what happens to each part of the profile, the conditions that make Shopify refuse a merge, and how to handle a cleanup that's too big to do by hand.

Can you merge customers in Shopify?

Yes. Shopify has a built-in customer merge in the admin, on desktop and in the mobile app. It combines two customer profiles that belong to the same person into one, and shows you the result before you confirm.

There are two entry points: from a single customer profile, or from the customer list. Both end in the same review screen. Neither finds duplicates for you. You have to know (or search for) both profiles first.

How to merge two customers from a customer profile

This is the route to use when you already have one duplicate open, for example after a customer emails to say their order history is missing.

1. In Shopify admin, go to Customers.
2. Click the customer profile you want to merge.
3. Click More actions > Merge customer.
4. In Find a customer to merge with, search by first name, last name, email address, phone number or credit card number.
5. Select the duplicate profile.
6. In the Merged customer section, review what will be merged and what will be discarded.
7. Optional: click Change contact information to choose which details to keep.
8. Optional: click View merge details, review it, then click Close.
9. Click Merge, then Confirm.

Step 6 is the one that matters. Once you confirm, there's no way back.

How to merge customers from the customer list

The list route is quicker when you spot two duplicates side by side, say after sorting or searching by a shared surname.

1. Go to Customers.
2. Tick the two customers you want to merge. If you can only see one of them, tick that one and you'll search for the other in a moment.
3. Click the horizontal menu icon next to Edit customers.
4. Select Merge customers. If you ticked two customers, go straight to the review.
5. If you ticked one, search under Find a customer to merge with and select the duplicate.
6. Review the Merged customer section, optionally change the contact information, then click Merge and Confirm.

In the Shopify mobile app the same action is called Merge entries: tap the menu icon on the customer list, choose Select customers, select the profiles, tap the menu icon again and choose Merge entries.

What happens to orders, emails and addresses when you merge?

Almost everything moves to the surviving profile. According to Shopify's help documentation, a merge combines orders, draft orders, addresses, email address, phone number, name, notes, tags, tax settings, timeline events, credit cards, customer accounts, gift cards and discounts.

Which profile survives depends on the contact details you keep:

A few details are easy to miss:

• Only one email survives. A Shopify customer has one email address, so the other one is dropped. If the person used both to sign in, they'll need the kept one from now on.
• Marketing consent leans toward subscribed. If the customer is subscribed to email or SMS marketing on one profile but not the other, the merged profile is subscribed. Shopify's page mentions email and SMS only.
• The customer isn't told. Shopify doesn't send any notification about the merge.
• Orders can't be moved one at a time. Orders stay linked to the account that placed them, and editing an order's contact email doesn't change that. Merging is how you bring them under one profile.

If the two profiles disagree on something important, like two different phone numbers, you can cancel, edit each profile on its own page, and try the merge again.

Why won't Shopify merge some customers?

Shopify refuses a merge when either profile has data it won't combine, or when the profile is mid-way through another process. The blockers listed in Shopify's help documentation are:

The tag and note limits catch stores that tag heavily through apps or automations. If you're merging three or four profiles into one, the totals add up with each merge, so trim tags or notes before the last one rather than after it fails.

For the blockers you can't edit away, like a subscription history, the practical choice is to leave both profiles as they are and add a note on each pointing to the other.

Can you undo a customer merge in Shopify?

No. Shopify states that a merge can't be reversed. There is no unmerge option.

That makes a short pre-merge check worth the time:

• Confirm the two profiles really are one person. Matching first names and the same city are not enough. Look for the same email after obvious typos, the same phone, or the same street address.
• Decide which email the customer should keep, especially if one is a work address they may lose access to.
• Export the customer list first if you want a record of the profiles as they were. A CSV export of your customers gives you a snapshot you can refer back to.

How to merge duplicate customers in bulk

Shopify's admin doesn't have a native bulk merge. To combine more than two profiles you repeat the merge for each extra one, and every pair is a separate search, review and confirm. That's fine for five duplicates. For 300, it's an afternoon of clicking, and the harder problem is finding the 300 in the first place, since the admin won't flag them.

Here's how the realistic options compare:

The developer route uses Shopify's GraphQL Admin API. The customerMerge mutation takes two customer IDs, runs the merge as an asynchronous job, and returns the ID of the customer that was kept. It needs the write_customer_merge access scope, and Shopify offers a customerMergePreview query so you can check the outcome before running it. You still have to build the duplicate detection yourself, and you inherit every blocker in the table above.

A worked example makes the difference concrete. Say a store migrated from another platform and then ran POS sales for a year, and an export shows about 400 likely pairs. Natively that is 400 separate merges, each started by searching for the right second profile. With a bulk approach you review the matched groups, preview them all, and confirm once, leaving the uncertain ones for a manual look.

How Twinfold helps

Twinfold is a Shopify app by NewClick (independent, not made by Shopify) that does the finding and the bulk merging, while still using Shopify's own customer merge underneath.

• Scan for duplicates reads your whole customer list through Shopify's bulk export. Scanning is free on every plan.
• It groups profiles by Email variant (the same address after lowercasing, removing a "+tag", and removing dots for Gmail), Same phone, and Same name and address, and shows "Why they match" on each group. Values shared by more than 20 customers, like your store's own address on POS sales, are ignored.
• Groups are rated High, Medium or Low confidence. Low-confidence groups and groups of more than 10 profiles go to Review manually and are never included in the one-click bulk preview.
• Preview all N high-confidence groups previews the High tab with Shopify first. You tick I understand that merged customers can't be unmerged and click Merge N customers, up to 250 groups per run.
• When Shopify refuses a merge, Twinfold shows the reason and leaves those profiles unchanged.

The Free plan includes unlimited scans and 25 merges a month, so you can see how many duplicates you have before you decide anything.

A simple order of operations

Whatever tool you use, the same sequence keeps a cleanup safe:

1. Export your customer list as a backup.
2. Find the likely duplicates and sort them by how sure you are.
3. Merge the obvious ones first: same email after normalizing, or same phone and name.
4. Review the uncertain groups by hand, and mark the ones that aren't really the same person.
5. Note the profiles Shopify refused and why, so nobody tries them again next month.

Done this way, a merge is a one-way door you walk through deliberately, not a mistake you discover when a customer asks where their orders went.