This answer comes from the Intercom Community forum. 👌

If you have multiple customers in your Intercom workspace with the same email address, it may be because you’re passing a different user_ID for each one.

When you define both an email address and user_ID for a user, Intercom uses the user_ID as a unique identifier.

For example, if you have two users, both with the email address test@example.com, but they have different user_IDs, Intercom will recognise these customers as two unique users.

While you can’t merge duplicate user profiles, you can clean these up. 👇

Read the whole thread and find out how to clean up duplicates, here in Intercom Community.