I want to UPDATE (not add) my customer list via CSV

Shopify Discussion

Topic summary

A user wants to bulk update existing customer records in Shopify by importing a CSV file to add tags, but discovered that Shopify’s native import function only creates new customers rather than updating existing ones.

The Problem:

  • After using MailerCheck to identify low-quality email addresses, the user has a CSV list of customers they want to tag and potentially delete
  • Attempted CSV import fails to add tags to existing customers
  • Goal is to tag these customers for filtering and deletion

Proposed Solution:
Another user suggests using the Shopify API (either GraphQL or REST) to accomplish this task, with the caveat that customers with existing sales records cannot be deleted.

Current Status:
The original poster indicates they lack the technical expertise to implement the API solution, suggesting they need a simpler CSV-based approach that doesn’t currently exist in Shopify’s native functionality.

Summarized with AI on November 19. AI used: claude-sonnet-4-5-20250929.
1

I used MailerCheck to scrub bad emails from my customer list. Now I want to remove those low-quality customers from my store.

I downloaded a CSV of the undesirable customers from MailerCheck, and now I want to tag that whole list so I can filter them and delete them from my store.

I thought I would just hit “Import” and create a tag for them so that these existing customer entries would be updated. Then I could delete everyone that now has that tag (see pic)

Trying to tag list of customers
Trying to tag list of customers3840×2086 359 KB

However, the Import function won’t update existing customers. It will only add new customers. So, the import fails, and none of these customers are tagged.

Customers exist... no tags added though
Customers exist... no tags added though3840×2094 361 KB

Is there another way I can add a tag to (or simply delete) all these customers?

2

you can do this via the API, note if they have records (Sales), it will not delete.

https://shopify.dev/docs/api/admin-graphql/2023-07/mutations/customerdelete

https://shopify.dev/docs/api/admin-rest/2023-07/resources/customer#delete-customers-customer-id

3

I’m sure that’s possible, but I’m just a guy with a csv.

1 Like