Around 48% of UK SMEs have been hit by a cyber-attack in the last year, with one in 10 experiencing more than four attacks.
Despite this, only one in five small businesses see cyber-security as a top priority, leaving the majority without adequate protection.
According to a survey of 250 SMEs by Barclaycard, one in 10 SMEs has never invested in improving website security while more than half (54%) said they lacked the knowledge and expertise to better protect themselves.
Cyber-attacks cost UK small businesses on average between £75,000 and £311,000 in lost sales, business disruption, recovery of assets, fines and compensation.
Barclaycard product director Paul Clarke said: “Cyber-security is not a one-off investment that can then be forgotten about, especially as criminals are becoming increasingly sophisticated in the way they target businesses.”