No. Once an account has been created in Portfolio Manager, it is not possible to change the username.
However, as a work-around, you can create a new account and "transfer" and/or "share" your properties with this new account.
- Create a new Portfolio Manager Account
- Connect with the new account (you need to be “connected” with to share or transfer)
- Transfer/share all properties into the new account.
- Transfer all Properties for which you are the owner/PDA: If you own all the properties, then its cleanest to transfer everything to the new account, and delete the old account.
- Share all Properties that you aren't the owner/PDA.