Why do people see the message "Sign-up not allowed"?

You can allow people to sign-up directly on your team portal. The URL for this is: https://{customdomain}.start.me/users/sign_up.

However, you will need to whitelist your e-mail domain(s) first. If you haven't done this, the following message will appear:

Whitelisting an e-mail domain (e.g., @mycompany.com) means that everyone with an e-mail address @mycompany.com can sign-up automatically and access your team pages.

More information can be found here:

• Configure team portal & SSO settings: Whitelisting e-mail domain