UK merchants say online fraud is now the greatest threat they face, costing them on average 400,000 pounds(US$648,920) in annual losses, according to a survey published on Tuesday by CyberSource.
The payments processing provider's sixth annual to be fraudulent.
Online businesses rejected an average of 4.6 percent of orders on suspicion of being scams, a figure CyberSource said was worrying, partly because some of the rejected orders were likely to be valid.
Read more of "Merchants lose £400k a year to online fraud " at ZDNet UK.