How do l write a letter to the bank to take my name off as a next of kin on a friend's death certificate taking to the bank? Question: My mother passed away.She does have a will and I was nominated as the executer and trustee. A conservator must wait 40 days from the date of death of the decedent before they apply to have their letters of conservatorship endorsed. The documents needed are a death certificate, residential proof, bank passbook, etc. To close a bank account on behalf of someone who has passed away, you must have legal authority to manage the account. Running Sketches of Men and Places, in England, France, Germany, Belgium, and Scotland.