Phone field on registration form not connecting to Mailchimp

Hi there, thanks for reaching out. You can map the phone field using a custom merge tag as noted here in our Wiki article: https://github.com/mailchimp/mc-woocommerce/wiki/Custom-Merge-Tags.

Please note, this would be something that is more technical in nature to accomplish. If you’re not comfortable facilitating, check out the Mailchimp Experts Directory for possible candidates to help you on your project: https://experts.mailchimp.com/

Good luck with everything and let us know if there’s anything else we can do.