Presentation Presentation – What is a Letter of Credit? Understanding the main characteristics and usage of a letter of credit. By Ozgur Eker (CDCS) - 27 January 2019 0 9557 FacebookTwitterPinterestWhatsApp BackNext4. Letter of Credit DefinitionUCP 600 defines letter of credit as: “Credit means any arrangement, however named or described, that is irrevocable and thereby constitutes a definite undertaking of the issuing bank to honour a complying presentation.” BackNext