The sole purpose of this form is to authorize the above named representative to complete the transaction indicated. (Personalized Seal).This Authorization Letter gives the owner of the letter the right to act on another person's behalf. A Letter of Authorization (LOA) must contain the following information: Letter must be on company letterhead. Authorization Letter. Please complete this printable form online or write legibly in blue or black ink ONLY. Office of Business Opportunity. Documents and Forms. Purpose of Authorization. Mention the date on which the letter is written.