To change your FASO login Username:

• login to FASO account Control Panel
• click gear icon - top right
• click Account Settings
• click Change Your Username
• enter new Username in the box
• click Save Changes

Only letters, numbers, underscores, and dashes are allowed.

Must be at least 4 characters in length.

Cannot exceed 50 characters in length.

This will also change your system domain/Subdomain, which is based on your username:

username.faso.com

Please see this FAQ for more info:
Username and FASO System Website Address Explained

Updated 5/25/2020 jyc