Make sure you are entering your information correctly. Most accounts have a Social Security number associated with it, so make sure you're entering that correctly. You can try using a different piece of information like your email or phone number, if you haven't already. If you filed a joint return, you could try using the SSN of your spouse.
If nothing works, you can always
create a new account.
Still having trouble?
Contact support at support@support.freetaxusa.com