These sample forms may be useful when filing documents for the civil and family courts. If you have any questions, consult an attorney.This section must contain the signature of the person who completed your affidavit, if other than you, the sponsor. These forms will be useful when filing required documents related to estates of deceased or incapacitated persons. Learn how to create an accurate affidavit letter with our free printable templates. We can accept a letter of sponsorship in place of a bank statement, also on official letterhead. Box 8: Type date signed. Box 9: The person who served the Defendant must sign his or her name. In this article, I'll share a sample affidavit letter tailored for immigration purposes. If you have a joint sponsor, they must also complete Form I-864.