Direct Answer
A goodwill letter is a written request to a creditor asking them to remove a negative item — usually a late payment — as a one-time courtesy. It works best when you have an otherwise good payment history and a legitimate reason for the late (medical issue, job loss, etc.). Here at Credisure Fix, we draft goodwill letters tailored to each major creditor's process, though a goodwill request is a courtesy and the outcome depends on the creditor and the credit profile. Here is more on when goodwill letters actually work and when they do not.