A written commitment to pay, by a buyer's or importer's bank (called the issuing bank) to the seller's or exporter's bank (called the accepting bank, negotiating bank, or paying bank).
A letter of credit guarantees payment of a specified sum in a specified currency, provided the seller meets precisely-defined conditions and submits the prescribed documents within a fixed timeframe. These documents almost always include a clean bill of lading or air waybill, commercial invoice, and certificate of origin. To establish a letter of credit in favor of the seller or exporter (called the beneficiary) the buyer (called the applicant or account party) either pays the specified sum (plus service charges) up front to the issuing bank, or negotiates credit.