To close a bank account on behalf of someone who has passed away, you must have legal authority to manage the account. Online: Use our online form to notify us about a customer's death.There are two ways to inform CCCU of a loved one's passing. The first option is to come into one of our six branch locations and speak with a teller. 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. Once the Affidavit of Entitlement is completed and notarized, attach a copy of the decedent's death certificate to it. Step 5: Present Affidavit of Entitlement. In Nevada, where a person passes away, the Executor of the Estate in the Will is expected to immediately file for a Letters Testamentary. You will need to provide a certified copy of the death certificate to close the account.