These samples will help you in creating a perfect authorization letter. Check out the samples of authorization letters to collect documents.The authorisation letter format to collect documents includes details of the person receiving the documents on your behalf and your personal details. Specify the Purpose: Clearly state why you're writing this. Empower a trusted representative with an Authorization Letter. Make a free Authorization Letter in minutes with our customizable template. This post will teach us how to write an authorization letter and provide sample authorization letters for reference. An agent authorization letter or approval letter is a written document granting a person authority to perform specific actions on your behalf. Milestone Documents. Complete List of Documents.