In this article, we explain what an official letter is and how to write one, plus we provide a template and example of an official letter for you to reference. A formal letter follows a specific format and uses formal English language.Keep reading to find out how to write formal letters. This program will help you write a letter that formally requests the money you are owed. This is called a Demand Letter. Fill out the contact information at the bottom with your full name, phone number, address, email and how you wish to be contacted (phone, mail, email).