Letter of collection,

Definition of Letter of collection:

1. Written notification of the pending amounts, meant to prod past-due customers to make a payment. Collection letters are sent usually one after another, with the tone and language getting more direct with each successive letter, until at least some payment is received. An effective letter of collection achieves its purpose without destroying the customers goodwill that was painstakingly acquired over the years. Also called dunning letter. Not to be confused with collection letter.