When you add contacts to an audience, we’ll automatically scan for duplicates to make sure each email address only appears once.
However, we don’t do this across all audiences in your account. If the same person’s email is in two audiences, we see that as two people. We typically recommend keeping a single primary audience in your account so Mailchimp can automatically prevent duplicates.
In this article, you’ll learn about duplicate contacts in your account.
Remove duplicates when adding contacts
Mailchimp automatically scans for duplicates when you add or import contacts to a single audience. If an address is found in an import file twice or more, we’ll only add it once. If you try to add someone who’s already in your audience, we’ll prevent it to avoid duplication.
Having multiple audiences in a Mailchimp account can sometimes cause problems with duplicates. If you think there might be some duplicate contacts across your audiences, you can combine your audiences into one primary audience organized with groups. When you do this, we’ll automatically scan for duplicates to make sure nobody makes multiple appearances.
If you have multiple audiences in your account and you want to keep things this way, that’s totally ok. The downside is that we can’t automatically find duplicate contacts. For example, if firstname.lastname@example.org is on Audience A and Audience B, Mailchimp sees that as two separate people. This could contribute to your monthly bill.
To find duplicates, add all contacts to one Excel spreadsheet. Then use Excel’s Remove Duplicates button to identify and remove duplicate entries. Make a note of the duplicates you removed from your Excel file, and archive them from one or more of your Mailchimp audiences.