When signing into the Customer Portal the default location for customer Login is

• https://<INSTANCE NAME>.atlassian.net/servicedesk/customer/user/login?destination=portals

However when Public Sign Up is enabled the Sign up for an account is not available at this location and is only located on the specific portal that Public sign up is enabled for even if there is only one service desk portal.

Suggestion:

Add sign up for an Account link to base service desk login page.

Workaround:

please refer to this knowledge-base article: Locating The Service Desk Portal URL For Public Sign UP