Letter of credit that cannot be changed or cancelled without the agreement of all parties, this being the norm in international trading. An irrevocable letter of credit gives the seller the security that the opening bank will make the payment if the documents stipulated under the documentary credit terms are presented as agreed. If payment is made via a correspondent bank, the opening bank can ask the latter at the demand of the principal to confirm the irrevocable letter of credit rather than merely issuing notification. The correspondent bank is then obliged to make the payment itself at the domicile of the beneficiary on due presentation of the documents (confirmed letter of credit). See also documentary credit.