Constant Contact’s new API and Formstack

What’s the issue?

Constant Contact is retiring their current API and moving to a new, updated version on 3/15/2021. In order for Formstack’s integration with Constant Contact to continue to work, we need to connect Formstack to Constant Contact’s new AP. This will disconnect your current integration that uses the old API.

When are we doing this?

We are going to connect to their new API on 11/10/2020. 

What will happen?

Once we do this, your current integration with Constant Contact will become disconnected, and you will have to reconnect your Formstack form(s) with Constant Contact to maintain the integration.

Additionally, Constant Contact’s new API handles certain fields differently:

  • Their new API doesn’t natively support “Address Line 2” even though that field remains in their application.
  • Their new API natively only syncs phone numbers that are marked “Home.”

If you are using Address Line 2 or Work Phone on your form(s) integrated with Constant Contact, these fields will need to be set up as Custom Fields in Constant Contact and mapped to the proper fields in Formstack.

How do you do that?

Within the builder for your Formstack form, navigate to Settings > Integrations > Constant Contact.  

Once there, log in to your Constant Contact account. 

Look at your field mapping below and ensure everything connected properly. The section below is where you will connect Formstack with the custom fields you’ve created in Constant Contact.

Once you have mapped everything properly, ensure the integration is turned on at the top of the page, and you’re done!

If you have more than one form connected to Constant Contact, you’ll want to ensure each form is properly connected with this updated integration.


If you are part of a team account, it is possible that someone else on your team has already done this. If you see that you’re already logged in to Constant Contact within the integration settings, then no action is required.

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