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How to switch from Mailchimp to Brevo without a CSV

Exporting a Mailchimp audience and importing it into Brevo works until it doesn’t. Fields get renamed, unsubscribed people sneak back in, and nobody can say how many contacts arrived. A direct migration avoids most of that.

Before you start

  • Create an API key in Mailchimp (Account, Extras, API keys) and one in Brevo (SMTP & API, API Keys).
  • Create the destination list in Brevo.
  • Check your Brevo plan can hold the contacts. Brevo bills you separately.

The steps

  1. Connect both tools in OpenContact under Connections.
  2. Open Move contacts. Pick the Mailchimp audience as the source and the Brevo list as the destination.
  3. Click Check what will happen. Nothing is copied. You see the source count, how many of the first 100 contacts would be copied, excluded or skipped, and which custom fields will be created.
  4. Start the move. Watch fetched, pushed and failed totals. Pause and resume whenever you need to.

What to expect

  • Subscribed contacts are copied.
  • Unsubscribed, bounced and complained contacts are not added to the list. They stay excluded, so a later import cannot bring them back.
  • Pending contacts (unconfirmed double opt-in) and transactional members are skipped. They never confirmed consent.
  • Merge fields become Brevo attributes. Address fields are split, for example into address_city and address_country.
  • Tags and groups are copied into a text field called tags in Brevo, for example “VIP, Webinar 2026”. Build segments from that field. Saved Mailchimp segments are not copied.
  • The count may be lower. Brevo keeps one contact per person. Someone who was in two audiences is one contact there.

If something fails

A contact Brevo refuses does not stop the move. When it finishes, download the failed contacts as CSV with the reason for each, fix the cause, and retry just those contacts.

Moving everything

To leave Mailchimp completely, use Move a whole account. Each audience is matched to the Brevo list with the same name, and they move one at a time.

Plan the move from Mailchimp to Brevo · Read the migration guide