Sign it and date it. There's no special format so long as who you are and the purpose of the letter is clear.Next of Kin Letter is a document used to confirm who is the closes relative of the deceased that are still living. This manual is intended to assist persons who are involved in the administration of a decedent's estate in Virginia. Virginia has no separate probate court. The will should be probated in the circuit court in the county or city where the decedent resided at the time of death. To close a bank account on behalf of someone who has passed away, you must have legal authority to manage the account. LETTER OF INSTRUCTION FOR NEXT-OF-KIN. Statements or other proof of the deceased's loans and other debts. Names and addresses of next of kin.