A Sussex firm is to change the way we pay for mobile phone calls after being bought for £12.5 million by Irish communications firm ITG Group.

Worthing-based Targeted Transaction Managed Services (TTMS) is pioneering swipe cards which will let pre-paid mobile phone users top up their accounts in seconds using cash.

Targeted at young users who do not have bank accounts, the cards will replace the current system of pre-paid vouchers.

Users will pay over the counter for airtime before swiping their cards through machines in shops which currently sell mobile phone vouchers. The payment will then be automatically credited to their accounts.

All the major mobile phone operators will take part in this scheme.

Vodafone is testing the swipe cards now and will be the first company to use the new technology.

TTMS was bought last month by ITG Group in a big-money deal which has put it at the leading edge of mobile phone payment technology.

It will draw on the technological and commercial know-how of its new owner to get the swipe-card machines into shops.

Operations director Janet Yeo said the swipe cards would make buying mobile phone time easier for those who prefer to pay in cash.

She said: "There is a big community of nine to 18-year-olds who do not have bank accounts.

"There's also a big cash community in Britain."

TTMS employs just 15 staff but provides mobile phone vouchers for 6,000 retail outlets across the country.

It also handles utility bill payments for 4,500 outlets.

The firm was bought last month by ITG Group so it could move into the British pre-paid phone market.

Ms Yeo said: "We believed we would be stronger as part of a global company."

TTMS made 1.12 million in pre-tax profits last year.