If one of your clients has a pending payment, here is a sample template you can use to write a notification letter for a pending payment.
To,
[Name]
Dear, [Name]
This letter is to kindly remind you of your outstanding payment for [Product] amounting to [Amount] which has been pending for [Number] days. I request you to fulfill this amount at the earliest.
We wish to clear all dues by [Date] and would appreciate it if you could pay the pending amount before or on the date.
Sincerely,
[Your name]
