Combine Lists From a CSV File

Combine lists to simplify list management and help reduce the cost of your Monthly Plan by eliminating duplicate subscribers across lists. To combine an exported or saved contact list into a master Mailchimp list, import a CSV.

In this article, you'll learn how to combine lists with the import from a CSV file tool.

Before You Start

Here are some things to know before you begin this process.

  • Be sure to back up your existing lists. Keeping a backup is a safeguard, in case you change your mind or something goes wrong.
  • To combine an existing Mailchimp list with another list, first export and download the list you want to move. We'll automatically keep your list's subscribed, unsubscribed, and cleaned addresses in separate files, which you'll need later in this process.
  • If you're on a Monthly Plan, you may want to delete your old list after you've exported your CSV file and before you import to your master list, to prevent your subscriber count from exceeding your current billing plan.
  • Combining lists only saves subscriber data, and doesn't carry over campaign activity or purchase history.
  • For seven days after you send any campaign, automation email, or RSS campaign, we place a temporary hold on bulk list actions. If you've recently sent to one of your lists, you won't be able to combine it until seven days later.

Task Roadmap

This is a multi-step process. You'll need to perform these steps in sequence to complete the task.

Import Subscribers

Remove Old Addresses

Combine Lists from a CSV File

To combine lists from a CSV file, follow these steps.

  1. Navigate to the Lists page.
  2. Click the drop-down menu for your master list, and choose Import.
  3. Choose CSV or tab-delimited text file, and click Next.
    import from csv or text file
  4. Click Browse to choose the list file you want to import.
  5. Check the I understand that my billing plan may be automatically upgraded box.
    Your account will only be upgraded if your list import causes your subscriber count to exceed your current billing plan.
  6. Click Next to match the columns in your CSV file to the columns in your Mailchimp list.
  7. Click Save for the Email Address column. We automatically match the column in your import that contains email addresses to the required Email Address field in your list.
    Image showing column import save options
  8. On the second column, click Save or click the drop-down menu to choose a different field type. If a column header is empty or the column can't be matched, click the drop-down menu to assign a field type to the column. To create a new column in your list, choose New Column Name.
    Image of create new column options
    Click Skip to exclude a column's data from the final import. This will not remove a column that already exists in your list.
  9. Repeat step 8 for all unmatched columns. You must match or skip all columns to complete your import. We'll display a success message when you've either matched or skipped all your columns.
    Image of pop-up success message
  10. Click Next to review your final import settings.
  11. On the You're all set to import screen, review the settings for your import. We'll display the method you chose for your import and the number of columns you matched.
    Image showing overview of import settings and list groups
  12. Click Details to view which columns you matched to fields in your list, or click Edit to make changes. If your list has groups set up, check the box next to the group you want to add these subscribers to.
  13. Click Import

Remove Unsubscribed and Cleaned Addresses

After you've imported subscribers from one list into another, be sure to remove cleaned and unsubscribed addresses from the master to help keep your list healthy and avoid emailing bounced and unsubscribed addresses.

To remove cleaned and unsubscribed addresses, follow these steps.

  1. Open the CSV spreadsheet files containing your cleaned and unsubscribed addresses.
  2. In Mailchimp, navigate to the Lists page.
  3. Click the drop-down menu next to the name of your master list and choose Manage contacts.
    click manage contacts
  4. Click Unsubscribe people.
    Image of Unsubscribe People option
  5. Copy the email addresses from the open unsubscribed and cleaned CSV files, and paste them into the field provided.
  6. Click Unsubscribe.
    Image showing list of emails pasted into unsubscribe field

Next Steps

  • Be sure to save all your exported CSV files in case you need your original lists again later.
  • Subscribers who exist on your old list will count toward your total subscriber count, which may increase your Monthly Plan rate, so you should delete your old list after you're done combining.
  • Update any signup form URLs, and pop-up, embedded, or hosted forms on your websites or social networks to match your new master list.

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