Login to the Third Federal app and select Check Deposit. You then select the account to deposit to and enter the amount of the check. Next, take a photograph of the front and back of the endorsed check (NOTE: You must write, "For TFS mobile deposit only" by your signature in order for the deposit to be accepted). Then confirm the information is correct and press Deposit.
You’ll get an email when your deposit is received. If the deposit is not accepted, you will get an emailed explanation of why. (If you do not receive an email, please update your email address by logging into Online Banking and click My Settings)