1. Look into granting financial power of attorney for limited transactions. The authorization letter must contain all the stipulation in the agreement including the powers, tasks, as well as limitation of the proxy.It's pretty much simple. This is an editable template for Bank Authorization Letter To Collect Documents, where you can edit it freely and quickly. With our customizable Bank Authorization Letter For Bank Transactions template, you can quickly and easily create an authorised letter in three simple steps. Submit the completed authorization letter to your designated bank branch. Include all necessary documents, such as identification for authorized signatories.