To close a bank account on behalf of someone who has passed away, you must have legal authority to manage the account. A magistrate can issue an informal probate order as soon as 7 days after the decedent's death.If you die intestate, the Commonwealth of Massachusetts will seek to first establish who the personal representative for your estate. If an individual dies without a will, Massachusetts intestate laws will determine who inherits their probate property. An Affidavit of Death is used to close accounts, receive benefits, or take ownership of property, real estate, or securities. The bank will not allow you to close it unless you have a letter of authorization from the probate court. The term refers to the distribution of the estate's final assets, which typically means that the Executor has run out of things to do.