To write a letter asking for payment, first state the detailed reason for the letter. Include supporting statements that back up the claim, and offer a method for resolving the matter, according to About.com. Thank the recipient in the closing of the letter. Keep the tone of the letter polite, direct and professional.
In the first sentence of the request for payment letter, explain the reason for the letter, About.com explains. In the second sentence, list the balance owed and the work done along with a notation as to when the money was due. Keep the letter short and direct.
Outline any possible methods of resolution, and provide the recipient with an incentive to make payment, such as offering to waive interest charges if you receive the payment by a certain date, or enclose an envelope for convenience, About.com notes. Including postage on the envelope is even more helpful, because the easier you make it for the person who owes money, the better your chance of receiving payment.
If it is a business entity that owes the payment, ensure the letter goes to the person in charge of disbursing payment, states About.com. A contact person for a business does not necessarily mean he's the person responsible for payment.