As a chip and Pin trial launches in Northampton this week, the success of using smartcard technology to combat credit and debit card fraud will hinge not on technology, but on communication.

Colin Grannell, managing director of Visa UK, warned that upgrading terminals, cards and cash machines over the next 18 months will be a huge project.

"We are already discussing with banks and retailers how to roll it out," he explained.

"It will involve millions of cards and hundreds of thousands of retailers. It will mean a big communication campaign. We are still trying to work it out."

Grannell pointed out that there are no technology issues with the system. "It is not a technology pilot. The system works; we know that through testing," he said.

"There were some issues around interoperability because of a mixture of chip cards being used, but they have been ironed out. Now it is about card holders having chip cards and knowing how to use them."

The trial involves 12 retailers, including small independent shops and large supermarkets, and 160,000 Northampton residents armed with new cards issued by the likes of Visa, Switch and Barclaycard.

Other shops in the area will join over the coming weeks until all are taking part by mid-June.

The modified cards contain secure smart chips allowing users to make purchases by keying in a four-digit Pin which is verified by the chip on the card.

The aim is to halve the UK's £424.6m credit and debit card fraud bill when the £1.1bn scheme is rolled out to 40 million consumers nationwide by 2005.

If a smart cardholder forgets the Pin, the system will "fall back" to signatures, said Grannell. But eventually this procedure will be removed as people become accustomed to the new secure method.

Evidence from the trial suggests that tapping in the four-digit code rather than signing a receipt will not cause delays at checkouts.

"You can put the Pin number in while waiting for goods to go through the till," said Grannell.

Although the UK is playing catch-up with other countries such as France, which has been using the Pin method for a decade and has seen an 80 per cent reduction in card fraud, Grannell explained that the UK has better technology standards than in France.

"France has a domestic proprietary system," he said. "The UK cards will have an international EMV specification and can be used anywhere in the world."