This page describes how to use Census with Mailchimp.

⠀Getting Started

In this guide, we will show you how to connect Mailchimp to Census and create your first sync.


1. Connect Census to Mailchimp

In the Destinations page in Census, Click the New Destination button under the Destinations section, and select Mailchimp.

You will be redirected to a page to log in to Mailchimp to authorize your account to Census. Once you enter your credentials and click the Log In button, you'll see a page like the image below, confirming you want to authorize Census.

Once you've authorized Census, you'll be redirected back to the Destinations page in Census and you should see your Mailchimp connection there.

If you want to see your connections in Mailchimp in the future, simply navigate to the Profile page, and scroll down to the Connections and notifications section.

⠀Mailchimp Field Quirks

Please note that the mandatory status field only accepts the following values in lower case: "subscribed", "unsubscribed", "cleaned", or "pending".

With Mailchimp, the API endpoint needs a Status field value, so if you find yourself seeing this error:

But you don't want to overwrite existing Statuses in Mailchimp, you just need to provide a mapping to the field labelled, "Status For New Subscriber".

Then your test sync, or completed syncs will be good to go, like this one:

If you do want to update the Status field, you can include that instead. However, we highly recommend understanding your organization's implications of potentially re-subscribing a member that has previously unsubscribed.

For more details, take a look at Mailchimp's API documentation.

⠀Supported Objects and Sync Behaviors

Object Name




List/Audience Members

Email Address, Prehashed Email Address (update-only)

Update or Create, Update Only

Learn more about all of our sync behaviors in our Syncs documentation.

Contact us if you want Census to support more Mailchimp objects and/or behaviors

Prehashed Email Identifiers

To prehash your emails, first lowercase the email address and then apply an MD5 hash, both which can be done directly in SQL. For example, here's the SQL you'd use in Snowflake (syntax for other data warehouses vary slightly)


Status and Unsubscribing List Members

The Mailchimp status field supports one of four values: subscribed, unsubscribed, cleaned, or pending. To unsubscribe a member from a particular list, simply set the status field to unsubscribed.


Mailchimp tags field can be set by providing an array of string values as structured data. Read more about syncing Structured Data using Census.

🚑⠀Need help connecting to Mailchimp?

Contact us via or start a conversation with us via the in-app chat.

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