If you indicate that the services are due to an accident (employment, auto, or other) then you must also supply an accident date.
How to Fix in Therabill
Click the edit icon next to the client. On the edit client form, go to the Advanced area by clicking the Advanced button at the bottom of the form. On the right of the Advanced form, you will see where you can enter the accident date. Make sure to enter the date in the format MM/DD/YYYY.
Remember to save the client before you close the edit client form. You can then resubmit your claim.