An authorization letter is a formal document that grants someone else the authority to act on your behalf for specific tasks or responsibilities. Specify the Purpose: Clearly state why you're writing this.Mention your name and a short description of who you are. Mention in the letter who are you authorizing to claim the money. Learn how you can create a letter of authorization to represent with the help of these writing tips and examples. Mention your name and a short description of who you are. Mention in the letter who are you authorizing to claim the money. Ensure that you specify the item or document being claimed. If you are authorizing someone to act on behalf of the company, there must be proper documentation to verify this. Signed: Date Signed:.