There are currently 100 million balance enquiries over the ATM network each month. 'Mobile ATM,' supported by several major high street banks, is a joint venture between Link, operator of the UK's network of cash machines, and MChex, a subsidiary of IT services group Morse PLC, with mobile network providers Vodafone, O2 and Virgin Mobile believed to be interested.

Users download the software to operate it, after which they need only enter their Pin number to look at their account. The service plugs directly into the cash machine network.

Mobile ATM will also allow customers who pay for their calls using pre-pay vouchers to top up their credit from their bank account. Developers claim Mobile ATM is as secure as the existing cash machine network.

The direct connection with Link will allow Mobile ATM to offer a host of other services, opening up the possibility of paying for goods and services as if a phone was a debit card.

Mobile ATM is pitched against Simpay, the Mobile Payment Services Association formed by Orange, Telefonica Moviles, T-Mobile and Vodafone.