Username is a unique sequence of characters provided by the users as their identifiers on a site. It serves as a direct link to the user, thus making it easier for them to be located.
On Freelancer.com, username is permanent and cannot be changed. Like the email address, the username should be unique for every account. The option to modify the username, a character of it or its whole, is not available to users.
If a user really wanted to change their username, they would have to close their Freelancer.com account and create a new account, with the correct username indicated. However, the details of the closed account such as the email address, feedback reviews and ratings, and even the completed projects cannot be linked nor transferred to the new account.
Alternatively, users can change their display names shown on their profile. This is the name seen on every user’s profile page. To know how to do this, you may refer to this article: How to Change Your Display Name