This authorization is valid until further notice. 1. Look into granting financial power of attorney for limited transactions.Formats and Samples of Writing an Authorisation Letter to Collect Documents. I am writing to request the opening of a bank account with your institution. A reference number is a unique identifier assigned to any financial transaction including those made using a credit or debit card. Authority to carry out the functions of the office.23. Get your refund status. Jedidiah Collins, CFP®. A Subaltern's Share in the War: Home Letters of the Late George Weston Devenish, Lieut. An Authorization Letter allows you as an account holder to grant another trusted individual to perform banking transactions on your behalf.