What happens when I change my username?
posted by IN Github
On the GitHub side, everything will behave as if your new username had always been your name. All of your repositories will now belong to that new name and the old username will essentially no longer exist. This can take a few minutes to complete after you initiate the change.
Links to your previous profile page, such as https://github.com/previoususername, return a 404 error. We cannot set up a redirect from the old username to the new one for references like @mentions.
However, redirects are setup for all your repositories. Both web and git access to the old location continue to function, and redirect toward the new username.
Warning:
If your old username is taken by someone else, they could potentially create repositories that override the redirect entries. For this reason, it’s recommended that all external links to repositories be updated.
