Abstract: The present invention relates to a method for processing of a payment transaction by means of a processing (finalization) computer system (2), such as a payment transaction system, such as a credit card transaction system arranged at a credit card organization, arranged for processing of the payment transaction, such as a credit card payment transaction, initiated at a POS system (3), such as arranged at a merchant, the method comprising steps of: —processing of payment transaction information, such as comprising an amount to be paid with respect to the transaction, from the POS system (3), such as from a transaction module thereof, —receiving of authentication information (140) with respect to the transaction, from the POS system (3), —transmitting (174) of authorization confirmation information relating to a confirmation of an authorization of the transaction to the POS system (3), characterized by steps for: —receiving (142), such as by means of a data assembly receipt module such as by means of a process