Thank you for reaching out to Atlassian Community!
Yes, if a customer already has an Atlassian account, when migrating their account it will just make them an internal user and also, for them to be able to access their tickets that they opened when they were customers.
If they have both a customer and an internal account on your site, the migration will merge the accounts. The customer account will be set as inactive and all the tickets created by them, comments, and any other history will be migrated to the internal account.
Based on your valuable feedback, we have released several new features to help you gain administrative flexibility with authentication policies, visibility into shadow IT with automatic product disco...
Connect with like-minded Atlassian users at free events near you!Find an event
Connect with like-minded Atlassian users at free events near you!
Unfortunately there are no Community Events near you at the moment.Host an event
You're one step closer to meeting fellow Atlassian users at your local event. Learn more about Community Events