Applicant's Father: Name. Passport No. Date of Naturalization. Signature.Clearly write name in mixed upper- and lower-case letters, including punctuation and accents. To file an Affidavit of Financial Information in Minnesota, you'll need to fill out a form and submit it to the court. A declaration letter declares a parent's intent in seeking custody orders. A declaration letter declares a parent's intent in seeking custody orders. My son's father lied on an affidavit about me to get temporary custody of our son. If I can prove it in court, will the case get thrown out? No one under the age of 18 can produce an affidavit, period. If your son has information that the court needs to know you should ask the court to appoint a GAL.