UK Internet bank Cahoot says more than 63,000 customers have so far signed up to use disposable credit card numbers when shopping online.
The webcard service - which uses controlled number technology from Irish security firm Orbiscom to give customers a new transaction number every time they make an online purchase - was first introduced by the standalone Internet bank in December 2001.
The bank claims that 100 customers a day are currently using the free system, which has been taken up by half of its current account and credit card base. Cahoot says that webcard has prevented £600,000 worth of fraudulent transactions in the first half of 2003.
Deborah Cutler, Cahoot's marketing director, says the system prevents rogue merchants from charging a higher amount than authorised or using card details to make multiple purchases.
"More and more people are seeing the benefits of webcard for shopping online," she says. "Webcard prevents fraud by totally blocking transactions from fraudsters who may otherwise have used customers' account details to obtain funds illegally."
According to figures from payments body Apacs, card fraud conducted via the Internet cost the UK £28m in 2002.