To close a bank account on behalf of someone who has passed away, you must have legal authority to manage the account. The affidavit is often coupled with a copy of the death certificate.The affidavit can then be used to complete the distribution of property. No letters of office are now outstanding on the decedent's estate, and no petition for letters is contemplated or pending in Illinois or in. The bank may require a certified death certificate in order to close the account and distribute the funds. 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. Take your letters testamentary and the check to your bank and see if they will cash it. In this video, we discuss an important aspect of estate planning: how to prevent your bank accounts from being frozen at the time of your death. In supervised estates, the court needs to approve the fees first or simultaneously with presentation of the account.