A survey of members by UKinbound has found 46% of their business comes from European Union markets.
The poll of 350 members was undertaken to get a deeper insight into why the majority of UKinbound members are backing the campaign to stay in Europe.
It follows an earlier Business Barometer which found 82% of members believe staying in the EU is important for their business.
The survey also revealed that 27% of its members’ workforces are made up of EU migrants.
"Our most recent survey demonstrates how important the EU is as a key source market for our businesses," said UKinbound CEO Deirdre Wells OBE.
"It’s also a clear demonstration of how the free movement of goods and people – that founding principle of the EU – is so vital for our business.
"The EU is a vital and vibrant market for inbound tourism, supplying two-thirds of our visitors, and one third of our industry’s employees. It would be economic suicide for us to leave."
