A letter of last instruction as an essential part of their estate plans. It's not a replacement for a will, and in fact it's not even a legal document.A letter of last instruction is a document that allows you to organize and give your family instructions pertaining to your final wishes. Most banks will have their own individual procedure for closing a bank account after the title holder of the account passes away. Describe the type of funeral or memorial service you want and where you want it held. Cremation or burial? Notify Bank of America. We'll ask you for the deceased customer's full legal name and Social Security number to identify their accounts. The bank will arrange the payment of the funeral invoice to the funeral home directly from the deceased's funds. A letter of instruction is a cheat sheet for anyone involved in settling your affairs.