Abstract. The realisation of electronic commerce process is very difficult without appropriate system for electronic payment. Of course it is possible to use some of the conventional payment instruments (e.g. payment cards, bills, payment orders), but these instruments do not fit with requirements for improving the commerce process. The resulting electronic commerce system would have disadvantages inherited from these conventional payment instruments. New electronic payment systems should be developed to satisfy all requirements of electronic commerce. The main idea of most of these systems is to convert conventional money to its electronic equivalent - electronic money.