Create a username
If you see "Username not allowed" when you sign up for your Google Account or Gmail, follow these guidelines.
Note: “Abuse” and “Postmaster” are reserved aliases, and you cannot use them as usernames or aliases. For more information, refer to our spam and abuse policy.
Choose a username 6–30 characters long. Your username can be any combination of letters, numbers, or symbols.
Usernames can contain letters (a-z), numbers (0-9), and periods (.).
Usernames cannot contain an ampersand (&), equals sign (=),underscore (_), apostrophe ('), dash (-), plus sign (+), comma (,), brackets (<,>), or more than one period (.) in a row.
Usernames can begin or end with non-alphanumeric characters except periods (.). Other than this rule, periods (dots) don’t matter in Gmail addresses.
Visit our Help Center for more information on how to change your username.