A Small Estate Affidavit, along with a copy of a certified death certificate, should be taken to the bank that holds the account. To close a bank account on behalf of someone who has passed away, you must have legal authority to manage the account.File with the Court a report of your administration and distribution, bringing the estate and your administration of it to a close. Full name; A copy of the death certificate; Social Security number; Account numbers; Date of birth; Date of death. The decedent had a bank account. The bank will not release the money. To start, you'll need to: Provide an original or certified copy of the death certificate. The bank will not allow you to close it unless you have a letter of authorization from the probate court. Often you can get them from the local Department of Health office in the county where the death occurred, or from the Washington State Department of. Health. You'll need the person's Social Security number and certified copies of their death certificate for most agencies and programs.