An old saying coming from the telecom world states that nothing can be really considered as a service unless you are able to charge for it. As we move towards a service-oriented society, the necessity to pay in real time for a variety of services via different channels anywhere, anytime, in any currency increases. According to Gartner (www.gartner.com), worldwide mobile phone sales totaled 816.6 million units in 2005, a 21% increase from 2004. Due to the high penetration rates of the mobile devices, they pose an interesting candidate for the real-time payment scenarios. Several efforts have already been done (Karnouskos, 2004), but as new technology comes aboard, new capabilities are also brought along. Near Field Communication (NFC) is such a technology, which due to the industry support and its low cost (in comparison with similar ones) may become dominant in short-range communication among a variety of devices, including mobile phones. NFC is well equipped in order to facilitate mobile payments with little interference from the user side.