A method of operating a point-of-sale (POS) system (1), the POS system comprising a POS terminal (3) having a software module (17, 21) thereon for enabling a retailer to process transactions within a transaction environment, and a peripheral device (5, 7) in communication with the POS terminal (3), the POS system (1) further comprising a driver software module (40) installed between the POS terminal (3) software module (17, 21) and the peripheral device (5, 7), the method comprising: receiving, at the driver software module (40), data sent between the software module (17, 21) and the peripheral device (5, 7) in communication with the POS terminal (3); communicating with a further device (44, 60, 64) in dependence on the data received at the driver software module (40); receiving modified data from the further device (44, 60, 64); and outputting the modified data.