Small business group ISME is warning companies to be vigilant after a sharp increase in the number of calls to its fraud helpline.
It says 68% of businesses have been a scam target in the past year - with the level of credit card fraud complaints at its highest ever level.
Spamming is still the most prominent scam at 86%, with phishing at 61% and viruses at 58%.
ISME chief Mark Fielding says scams are seriously damaging SMEs.
"If there has been fraud in businesses, it tends to keep customers away from it as such," he said.
"Crime in Ireland, as we've seen from a recent survey that we have done, is costing small businesses €1.5bn."