A power of attorney is an important and powerful legal document, as it is authority for someone to act in someone else's legal capacity. Learn which letters of administration in Florida are required during estate proceedings, why they're necessary, and how to obtain them.IT YOURSELF (DIY) DOCUMENT⭐ ➡️ Not sure how to write an Authority Letter? No, a lawyer is not required. A signed letter on your bank's letterhead verifying your account information must be attached. The letter also must verify. Certificate of authority Florida refers to a legal document necessary to register a foreign (or out-of-state) company with the Department of State of Florida. Notify Bank of America. We'll ask you for the deceased customer's full legal name and Social Security number to identify their accounts. To close a bank account on behalf of someone who has passed away, you must have legal authority to manage the account.