Guidelines for creating a custom username or screen name on Facebook
When you create a custom username for your Page or profile, bear in mind that:
- You can only have one username for your Page or profile, and you can't have a username that is already being used.
- Usernames can only contain alphanumeric characters (A-Z, 0-9) and full stops ("."). They can't contain generic terms or domain extensions (e.g., .com, .net), including country extensions (e.g., .ie, .de, .ca) .
- Usernames must be at least five characters long.
- Full stops (".") and capitalisation can't be used to differentiate usernames. For example, johnsmith55, John.Smith55 and john.smith.55 are all considered the same username.
- Usernames shouldn't impersonate someone else.
- Your username must adhere to the Facebook Terms.
Usernames for Pages
Bear in mind that you must be an admin to create or change the username for a Page.
You may not be able to immediately create a username for a new Page if you've recently created several new Pages. A Page's username can also be removed because of inactivity.