Welcome! My goal is to do my very best to understand your situation and to provide a full and complete answer for you. Good morning. Only the borrower needs to sign a promissory note. A promissory note is essentially a written IOU and it's simply a promise that the borrower is making to repay the lender. The lender need not sign because it will be the lender filing the suit to enforce the promise of the borrower. I hope this has givenyou information that has been helpful to you.