MailChimp apparently just changed their policies.  In the past we have always set up the account for the club and then added ourselves as a user so we can assist with any issues or questions. As of this week we're unable to do that without moving them onto a higher tier.

We had been planning to switch to a built in tool and send out via SendGrid anyhow, this is simply going to expedite that. We're already working on a replacement for MailChimp. For the moment -- assuming that is the issue you're running into -- you'll need to simply share an existing login with the new person or upgrade the account.