Merge users based on email?

  • 14 February 2022
  • 2 replies

Is it possible to merge users that have the same email?

We have the following flow:

  1. We send users emails and log an event in Amplitude with that user's email for every email we sent
  2. Later, some users convert on the website and get assigned a user ID. 

Can we merge that user record in Amplitude to the anonymous user created earlier on the basis that their email is the same? i.e. there should be no users with duplicate emails in our database, emails should be treated as unique




Best answer by Saish Redkar 14 February 2022, 22:36

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2 replies

Userlevel 7
Badge +10

Hey @dchouinard 

Afaik, that is technically only possible if you are setting the user’s email ID as the user_id, which is not an ideal practice. You can read more on this in the following resources -

Hope these help in further clarification.

Userlevel 4
Badge +7

Hey there,

thanks for writing in!

A user ID should be something that does not and will not change. If it does, Amplitude will have no way of knowing it's intended to represent a currently-existing user, and will instead assume it stands for a separate user.

Anonymous users should not be assigned a user ID. These users will still have Amplitude IDs and device IDs. Users will later be merged when Amplitude recognises the different user IDs belong to the same user.

Here is a few helpful articles that describe how user_id works:


Hope this clarifies it further :)