Note: Goodwill letters are meant to be personal and reflect your individual situation. Therefore, this is only an example to give you some ideas.

[your full name]
[your full address]
[your full phone number]

Dear Sir or Madam
This letter is in reference to a paid collection with the account number [xxxx].
In [year] a collection for the amount of [xx.xx] was sent to your agency due to a series of hardships and medical problems in my life. While I normally make great strives to honor my debts and fulfill my responsibilities, at the time of the debt I was unfortunately unable to. I have since gotten back on my feet and paid this debt to your agency.

I am now trying to buy a home, however I am having difficulties receiving an affordable rate due to having a collection on my account. I am kindly hoping, given the date and amount of this collection, if your collection agency would consider removing this collection from my credit report as a gesture of goodwill. This kind gesture would sincerely be appreciated and an invaluable gift to my family and I.

Sincerely,
[your name]