: The growth of mobile commerce is directly related to the increase of ownership and use of mobile personal, programmable communication devices, including mobile phones and PDAs. These devices provide effective authorisation and management of payment and banking transactions since they are capable of offering security and convenience advantages compared with existing methods, such as credit/debit card transactions and online payments through a PC. Some of these advantages are part of the existing devices’ functionality while others require modest, inexpensive enhancements likely to be incorporated in the mobile devices to come. It is expected that the use of secure and convenient mobile personal devices can revolutionise the payment, banking and investment industries worldwide. This paper presents SEMOPS, a secure mobile payment service implemented on innovative technological solutions and introducing a competitive business enabler of mobile commerce. SEMOPS intends to exploit the business opportunities inherent in the billing, cus-tomer-service, technical relationships and banking services among mobile customers, mobile operators and banks in order to offer a competitive solution to existing payment services.