credit, letter of
letter of credit, commercial instrument through which a bank or other financial institution instructs a correspondent institution to advance a specified sum of money to the bearer. The document is called a circular letter of credit when it is not addressed to any particular correspondent. In effect, a letter of credit is a draft, save that the amount is merely stated as a maximum not to be exceeded. Letters of credit, mainly used by travelers, greatly simplify nonlocal business transactions. Those who issue such letters are usually so well known that any bank will honor the letter upon proper identification. Travelers' checks are a modified form of a letter of credit. They are issued in coupons, upon whose face a value is usually expressed in terms of the currency of a particular country. In the United States they are issued by express companies and banks. Circular letters of credit require that each payment, as it is made, be endorsed by the firm making payment so that other banks may know how much of the total credit has been used.