How do I remove the ability for customers to sign up for our account?

Question

How do I remove the ability for customers to sign up for our account?

Answer 

To remove the option for your customers to sign up to your Help Center, disable the Anybody can submit tickets option.

Open Admin Center, then navigate to People > End users. Then, disable the option Anybody can submit tickets.

For more information, see the article: Workflow: How to hide the sign in button from the help center.