UK payments body Apacs is urging online banking customers to remain extra vigilant following a 180 per cent surge in phishing emails in the past year.

The number of reported cases of fraudsters attempting to steal bank details using bogus emails more than doubled in the first half of 2008, the payments authority said.

There were more than 20,000 attempted phishing frauds involving banks and building societies in the first six months of 2008, compared to 7,224 a year earlier.

Robust banking systems are partly to blame for the surge, forcing fraudsters to resort to phishing techniques to con online bank users into revealing their account details.

According to Apacs, half of all internet users in the UK bank online, growing from fewer than 3.5 million in 2000 to over 21 million last year.

Sandra Quinn, communications director at Apacs, said that she expects more people to use online banking in the future to make payments rather than just checking balances, particularly in light of the new faster payments service.

"However, we strongly urge banking customers to make sure they remain wary of online scams such as unsolicited emails claiming to be from their bank," she said.

"Only use a fully protected PC with regularly updated antivirus software and a firewall installed and switched on."

Despite the rapid rise in phishing scams, Apacs said that overall losses through online banking fraud fell to £22.6m in 2007 from £33.5m in 2006, representing a 33 per cent decline.

Apacs has published a Bank Safe Online advice guide for customers to help spot common phishing techniques.