Abstract: This is a method to carry out safe transactions using programmable mobile telephones. The use of programmable handsets—for example with Java technology—, to which an application is downloaded (e.g. Java application) allows people to carry out safe transactions. The application allows the buyer/seller to carry out the transaction, including the verification, with just one connection. The data that was sent is then encrypted and transmitted via GPRS or any other data transmission protocol, to a transactions server, where the transactions are verified and authorised. The security of the process is provided mainly by the use of up to five non related identification elements, including an access key unique for each user, stored in the mobile handset.