A goodwill letter is a courtesy, not a right
A goodwill letter asks a furnisher to make a courtesy adjustment — for example, on a paid late mark. Courtesy means they can say no. It is not a right under the FCRA, and it is not a dispute.
If the information is inaccurate or incomplete, that is a dispute, with a 30-day investigation clock once a complete dispute is in. If the information is accurate and you still want to ask, a goodwill letter is optional. The Credit Attack Kit is the checklist for writing and tracking what you send. No deletion promise.