Simply said, interest received from an insurance company should not be entered into the program.
The payment portion of the system is a giant ledger. It is used to track charges and the payments that correspond with those charges. This application is not meant to take the place of a full accounting system, such as Quickbooks.
I still want to enter interest income into Therabill
Ultimately, all sessions should have a zero balance after all payments and adjustments have been applied. Entering insurance interest would cause an overpayment onto a session. Therefore, you should never enter interest received without first creating some kind of charge for it. You can manually add a session and use a Session Class that you have designated for interest. This will also give you the ability to run custom reports for the interest you have posted. For more information, see: Add a Session.