This specialist thesis brings out explanation of payment card processing as a concept of informatical analysis, development and managing of debit and credit card transactions. Throughout the example of Društvo XY business, it is represented how that kind of service is provided. Card industry is very innovative and increasing industry so it is very important that processors adjust their services, hardver and softver maintenance of payment card monitoring and adjust their business to new technologies on the card payment market. Also it is very important for processors to upgrade the architecture of card processing system in accordance to special needs of their clients, card issuers and acquirers. In thesis it is also presented the development of card industry through history, from first paper card till todays virtual card, in the world and in the Croatia, that is successfully following world trends in payment card industry. NFC technology is the future of card payments, developing contactless cards and contactless terminals to accept these kind of cards. Cloud computing and HCE technology opens the door to some new term of card business, especially interesting to young generations in following of new technologies and mobile developments. Revenues that processors have and costs that occurring as a result of providing their services, require developing and implementation of ERP systems in companies. That ensures easier business process following and simplest business result reporting, as a background for successful planning and correct decision making. Accounting information system enables employees to analyse data more detailed and more efficient through data wharehouse, in real time and with real data. That enables repair actions and reactions on possible incidents on time. Relatively unknown term in everyday card usage, payment card processing is very important and crucial part of every card transaction. Probably nobody asks himself what happens when we use credit card on POS or ATM terminal, but for processor it means starting with very complex and expensive process. At the same time it is very important to take into consideration compatibility with PCI DSS standards and personal data protection of every client, card issuance or card acceptance.