Letter of Credit (L / C) is the most commonly used payment method for international transactions, being particularly required for high value contracts or where there are doubts as to the solvency of the business partner (s) the main advantage of this payment technique being the guarantee it offers to those involved - exporter, importer, banks - with regard to the defense of their interests in the payment process, without taking into account the fact that the good execution requires the exporter rigorous administration work - having beneficial consequences in the proper conduct of contract relations due to the obligation to comply with the L / C clauses - and the importer incurring specific costs, which is why the letter of credit is a means of safety and mutual control , aiming to ensure the vendor will as well if the delivery has been made on the terms and conditions established by the buyer, the counter value of the goods delivered.

 Four parties are involved in the development of a documentary credit, namely:

- the ordering party (the importer / buyer), who requests his bank to open the documentary letter of credit - for this letter of credit is a declaration of irrevocable payment in favor of the exporter, subject to the submission of documents, requested contractually and inserted as a letter of credit by the beneficiary its bank;

- the issuing bank (the bank of the importer), who, upon the importer's request, accepts the payment commitment;

- the beneficiary of the letter of credit (the exporter / seller), the person in favor of whom the letter of credit was opened and the person presenting the set of documents in the bank in order to collect the value of the delivered goods - for this documentary letter of credit appears as an irrevocable payment promise from a bank, the submission by him, within a certain period of time, of the set of documents attesting the dispatch of the goods or which are expressly requested by contract and reflected in the conditions of the documentary letter of credit;

- the exporter's bank (the notifying / notifying / paying / negotiating bank), which serves the beneficiary of the letter of credit.