Legal Question in Consumer Law in Massachusetts

Re: depositing a check

If the check is made out to both, both must sign it. If you sign the mortgage company's name to the check, you will be committing forgery. That is a crime, and thus inadvisable.

You need to work this out by honest means.

I would suggest the following: send the check to them with your signature on it. Photocopy front and back. Add a letter telling them to return the exact extra amount within 14 days, or you will take all appropriate legal action. Copy that as well. SEND THESE BOTH BY CERTIFIED MAIL.

You will wait the 14 days. On the 15th day, send a written demand for relief BEFORE filing suit, seeking your money back. Send it by certified mail, give 30 days to respond, and EXPRESSLY ADVISE THEM THAT YOU WILL FILE SUIT UNDER MASSACHUSETTS GENERAL LAWS c. 93A if they do not return your portion of the funds within 30 days.

After the second thirty days (after receipt) have passed, you can file suit. If the amount is below the small claims limit, you will be able to do it in that session. The clerk magistrate, seeing the paper trail at hearing, will almost certainly be happy to award you triple damages (unless your initial math is entirely wrong).