Below is a sample reminder letter: ---------- Dear Mr. Clinton: Recognizing your very busy schedule, I’m sending you this note as a reminder to renew your Cleaning and Maintenance Contract with us. I hope you have been more than satisfied with our service so far. Enclosed is a copy of the original contract for your convenience.

Start the letter with a salutation like Dear Mr/Ms. [person name] or Dear Sir/Madam. Mention the reason for the reminders, such as the invoice number, due date, and reason for payment. Request or demand immediate payment. Explain the consequences of not making the payment before the deadline.