Just 17% of 361 companies in the UK, according to market analyst firm Rhetorik, run Web sites which are transactional, even though 97% of public and private sector organisations have Web sites.
Lowest usage is in wholesale and retail organisations, with 15.4% running one.
The highest-scoring sector is finance and banking, where 41.7% of organisations have transactional sites.
According to the research some 45% of respondents - mainly IT managers - said concerns about security were holding back transactional functionality deployment, while 54% blamed budget restraints.
Some 22% said their companies could see no business case for having a transactional Web site. But a third of those without such functionality plan to add it in the next year.