Is there any way to restrict internal users from signing up for Jira?

[Juan Zhang]

Looking for a way to prevent user within our domain to join Jira and use license seats without admin approval. 

[Andy Heinzer]

@Juan Zhang I would recommend reviewing our documentation in https://support.atlassian.com/user-management/docs/control-how-users-get-access-to-products/

Your site most likely has been setup to use an approved domain.  When that is configured any user on that domain can automatically join your site.  If you don't want that, remove the domains from that configuration page. This way you could setup a system where users must be invited or have an invitation link URL.

[Rebekka Heilmann (viadee)]

Hi @Juan Zhang and welcome to the Community!

Check out this documentation: Control how users get access to products | Atlassian Support

You can change the Access settings for each Site and Product in your Atlassian Org (and also per Domain) to

• No automatic access
• Access after admin approval
• Automatic Access without approval

Moreover, you can de-/activate User Invitations.