To close a bank account on behalf of someone who has passed away, you must have legal authority to manage the account. When the decedent died, you automatically have full ownership of that property, so it is not part of the estate.Follow the bank's procedures: The bank will likely have you fill out some forms and provide the necessary documents to close the account. This set of forms is for use in probate proceedings. The forms must be filed in the probate court. You need to take your mother's death certificate to the bank. They will freeze her account and flag it "Estate of the Deceased (mother's name)". Find that the decedent died intestate (without leaving a will).