Sample Letter to Bank Informing the Death of the Account Holder. The death claim letter should be written in the formal letter format.You'll need the person's Social Security number and certified copies of their death certificate for most agencies and programs. Social Security and Medicare. You will also need to provide a certified copy of the death certificate. A letter of last instruction is an organized way for you to give your family all the facts about your finances—and have a basic tool for your own. Online: Use our online form to notify us about a customer's death. Consider sending a letter to all creditors notifying them of a possible delay in payments owed the creditors because of the death. Online: Use our online form to notify us about a customer's death. We'll need a photocopy of the death certificate to verify the identity and legal residence of your loved one as well as confirm date of death.