A method of operating a ticketing system comprises generating data representing ticket information and transmitting the same for reception by a mobile station over a mobile communications network link. Data from the mobile station can then be used to verify a transaction. The method involves generating a ticket and afterwards representing said ticket as a bar code on the display of a mobile phone. The bar code being scanned by a scanner. The SMS messages having a flag in the header for storing SMS relating to tickets in a special directorate.