You sure can—and we’ll show you how at the end of this explanation.
Just keep in mind that your current tracking links contain your username:
If you change your username, all the links inside your account will immediately use your new username, breaking any external links that you have on websites, on blogs, in banners, in emails messages, or that you’ve given to paid traffic sources, and so on.
In other words, be aware that you can definitely lose traffic if you don’t immediately go out and update all of your external links.
Be especially careful about changing your username if you’ve got any paid traffic currently arriving and you gave the ad or traffic source a link—like the one above—that contains your username. If you have, let all the traffic arrive before changing your username.
Note: If you’ve created a custom domain using a CNAME DNS record and you’ve been directing all your traffic through that domain which does not contain your username, then you can change your username without worrying about losing any traffic. In this case, because your custom domain doesn’t use your username, it’s not affected when you change your username.
Caution: If you’ve set up a custom domain using the Script Forwarding method, you’ll need to update the index.php file you uploaded to your server because it contains your old username.
Once your username has been changed, simply Regenerate Your Custom Files and upload the new index.php file, replacing the previous one, and you’ll be all set.
If you’ve got the technical knowledge, you can also manually edit your existing index.php file using a text editor and simply change the username yourself. Remember to upload the edited file unless you’ve edited it directly on your website.
For more information on setting up Script Forwarding, read this article: