How to change a username

Your username is the email address you use to log in to your Fastmail account. You can change your username at any time, and all admin users can rename their users' accounts.

For security purposes, you cannot change a username more than twice every seven days, or more than once in 24 hours. Your username cannot be changed during your trial period.

To rename an account:

  1. Go to the Settings → Users & Aliases screen.
  2. Type in your password at the top of the screen and click Unlock so you can make changes.
  3. Click the Edit button on the user you want to rename.
  4. Enter what you'd like your new username to be. Check your new address to make sure it's exactly what you want.
  5. Click Save.

Note: when you rename an account, the old address will be automatically added as an alias. This means emails can still be sent and received to and from the old address, so you don't accidentally lose any mail sent to your old address.

If you don't want to receive emails sent to the old address, delete the alias on the Settings → Users & Aliases screen.

Why can't I have a dot in my username?

Due to an internal technical limitation, we cannot allow dots (.) in usernames at Fastmail domains. However, we do support dots in usernames at your own domain. We also allow them in aliases, even at Fastmail domains.