Setup
- In Mailchimp open Profile → Extras → API keys and create a key. It ends with your data centre, e.g.
-us21. - Find the Audience ID under Audience → Settings → Audience name and defaults.
- In FormSubmit, open your form → Integrations → Mailchimp and paste the key and audience ID.
- Optional settings:
- Email field name — defaults to automatic detection (
email, then any field containing "email"). - Double opt-in — new members are added as
pendingand Mailchimp sends a confirmation email. - Tags — comma-separated tags applied to the member.
- Email field name — defaults to automatic detection (
- Click Send test.
What gets sent
FormSubmit upserts the member (existing subscribers are updated, not duplicated), sets FNAME/LNAME from first_name/last_name fields or splits a single name field, and applies your tags. Submissions without a valid email address fail with a clear error in the delivery log.