Is there a specific form we should use to notify a person who has signed a personal guaranty that we are having trouble collecting from the debtor company?

Answer: No, There are no specific documents required. I usually send a letter that says something like this:

“I have been informed by NAME that ABC Company is having serious financial problems, and is unable to pay the balance owed to this company of $xxxx. On DATE, you signed a Personal Guaranty and became liable for the debts of ABC Company. As a courtesy, we are sending this letter in the hope that you can persuade the company to remit payment to us immediately. Please call me if you have any questions at xxx xxx-xxxx.”