A survey by Zen Internet has found 22% of UK firms have a dial-up connection, an equal proportion to those with fibre optic broadband.
Nearly a quarter of UK businesses have dial-up internet, according to research.
A survey of 100 senior IT managers found 22% of offices have adopted 'superfast' fibre optic broadband. However, the exact same proportion still has older, much slower dial-up lines installed at their company premises.
The research was carried out by Computing magazine in partnership with Zen Internet, a specialist provider of business broadband.
Stephen Warburton, sales director at Zen Internet, said: "There are lots of headlines about building even faster networks in the future, but generally a lack of easy-to-understand information about fibre optic broadband services available today.
"We're concerned that in combination, this is slowing the uptake of faster services that are available to about 50% of premises in the UK."
Openreach, the local networks division of BT, is currently working with the government and councils across the UK to bring superfast fibre optic broadband to 90% of homes and businesses nationwide by the end of 2015.
Warburton went on to say that it's important for businesses, as well as consumers, to weigh up their options before choosing a broadband provider.
"Just as connectivity services differ, so do the providers of those services. Unfortunately, intermittent outages were experienced by 41% of respondents to our survey, with 24% having had poor levels of support - highlighting the need to carefully evaluate providers."
Unsurprisingly, the most common type of business broadband connection was found to be leased lines, which provide a faster connection via broadband cabling that isn't shared with other customers based nearby, as would normally be the case.
Zen Internet, which is based in Rochdale, Greater Manchester, recently announced plans to invest £3.5million to expand its network beyond London, Manchester and Leeds.