Thanks for your feedback! Fully deleting users is not supported in order to retain the user's test history etc. throughout TestRail, but deactivating users has basically the same effect (the user is no longer counted against the license limit or subscription fee, cannot log in anymore and can no longer be selected in user dropdowns, such as the Assign To fields for tests and test runs). As Marty mentioned, you can hide the inactive users from the user management page by choosing to display Active users only, and this is the recommended approach for this. Renaming a previously marked inactive user to a new user would skew the original and new user's history/metrics, so we wouldn't recommend this. Hope this helps!