Since Mailchimp API version 3 all e-commerce data is now tied to a single Mailchimp audience. This means that you will not be able to change the connected Mailchimp audience unless you synchronise all of your WooCommerce products, orders & customers with this new audience.

Greyed out list setting
After the initial setup, the Mailchimp list setting is disabled in the store settings.

Synchronising with a new Mailchimp list

To connect your WooCommerce data to a new Mailchimp list, please take the following steps:

  1. Go to the MC4WP > Ecommerce page in your WordPress admin.
  2. Scroll down and use the “Reset Data” button to reset your e-commerce data.
  3. After the page reloads, use the wizard to connect your store to a new Mailchimp list.

Wizard to connect WooCommerce to a Mailchimp list