METHOD FOR CHECKING INDIVIDUAL PAYMENT DOCUMENTS AND COMMERCIAL INVOICES

摘要

The invention relates to a method for storing and checking data about transactions, in which transactions a purchase price (KP) is paid and a payment document (7) is handed over at a point of sale of a commercial enterprise (H). Data about the location, time, and purchase price of the transaction are transferred from the point of sale to a recording and transmitting unit (1) arranged at the point of sale, which creates a transaction log and an operation log on the basis of an encryption specification that identifies the recording and transmitting unit (1), and the recording and transmitting unit (1) sends the transaction log and the operation log to a publicly inaccessible data memory (5), which is accessible to a checking station (P). According to the invention, the recording and transmitting unit (1) sends the identification number (IN) to a payment document printer or a stamping device of the point of sale for output on the payment document (7), and in encrypted form - encrypted using the help of the purchase price (KP) - to a data memory (6) that can be publicly accessed by inputting an access code, wherein the access code is the identification number (IN) output on the payment document (7) together with the purchase price (KP).