From :
(your name)
(street)
(city, state)
_______________
(date)

To,
(name)
(street)
(city, state, zip)
________________

Dear Mr. _______,

We are interested in our customers and are always trying to find new ways to improve our service. For these reasons, we are inquiring why there has been a further delay in paying your long overdue account. we must remind you of your open account, that is now a 15 days beyond, our 7 days payment terms.

Despite the fact that you have ignored our previous reminders, you can no longer delay payment if you wish to keep your account open.

We have repeatedly written and phoned your office asking for the payments. As a business person you must understand that we also have a business to run for profit.

We expect a payment of ________ (dollar amount) from you on or before ________ (date).

We do expect your cooperation in this matter at the earliest.

Yours sincerely,
___________,(name)
___________,(title)
___________,(phone/fax/e-mail).