Mailchimp Facebook Conversion API Tracking

Mailchimp Facebook Conversion API

Since the release of iOS 14 and its impact on how Facebook receives and processes conversion, Facebook has been recommending the use of its Conversion API for tracking conversions as opposed to relying on the Facebook Pixel.

This article will show you how to send a Facebook Conversion API event (such as Lead or Purchase) when someone is added to your Mailchimp List. This should lead to more accurate conversion tracking.

Before we get started, you’re going to need a Zapier account, and you copy the Zap I created here.

1. Set up The MailChimp Trigger

Zapier Mailchimp Action

Once you’ve copied the Zap, you’ll need to update the Mailchimp trigger with your own Mailchimp details.

  • Make sure the Trigger Event is New Subscriber.
  • Connect your Mailchimp account
  • Choose the Mailchimp Audience (List) that new subscribers get added to after they interact with your Facebook Ad

2. Setup the Facebook Conversion Action

Send Lead Events in Facebook Conversions
  • Make sure the Facebook Conversion action is selected
  • Action Event: Choose the event that’s most appropriate. If someone signs up to your newsletter via Mailchimp, then it’ll be a Send Lead Event, but if someone ends up on your List after purchasing something, then you might want to make it a Send Purchase Event.
  • You will have to connect your Facebook Account during this step
Setup a Facebook Conversion Action
  • Choose System Generated as the Action Source then select your Facebook Business account and the Pixel you use for tracking.
Event Info
  • In the Event Info area, I used the Mailchimp User ID in the Event ID fields, this should prevent duplicates.
  • Grab the Test Event Code found in the Facebook Event Manager
Facebook Event Manager Test Code
  • Map the Mailchimp fields to the customer information fields.
Map Customer Information

3. How to Test Your Mailchimp Facebook Conversion

Finally, test your setup. You should be able to see the following test event in the Facebook Test Event area.

Facebook Test Event

Also be sure to check your event history after a couple of days.

Facebook conversion History

By Luke Moulton

Founder of