Ahead of Thursday's vote on the idea, London's mayor, for instance, joined 140 representatives of the city's "leading tech and creative firms" to release a letter urging a vote for "remain."
"Our capital has the potential to be the Los Angeles, New York and Silicon Valley to the rest of Europe - and fuel the creation of new jobs across Britain. Let's not put that at risk," London Mayor Sadiq Khan wrote in the letter today.
But that position isn't universal.
Russell Stern, the CIO of Solarflare Communications, a global provider of application-intelligent networking I/O software and hardware, thinks an exit might help his Irving, Calif.-based company.
"The EU has created more regulatory barriers, not less," Stern said in an interview. An exit from the EU could allow the UK to compete as a place with less regulation, with a positive business impact, he said.
Stern said that specific to his firm, a "yes" vote to exit could prompt Europe's financial services industry to concentrate in the UK, increasing demand for Solarflare's technologies.
Solarflare operates a research center in Cambridge, England and its two co-founders are from the University of Cambridge.
The immigration mobility now allowed in the EU has been seen as a plus for businesses. Stern says new immigration rules that would likely result from a break by the UK might increase the amount of time it takes to hire someone from another country. Bt he doesn't see it as an outright barrier to high-skilled help.
As for his personal view, Stern said he feels the UK ought to move ahead with the exit because the business environment today "is too cumbersome," and he would like to see "the UK maintain its identity."
The affects of an exit, said Jeff Broadhurst, the CEO of ERP vendor Apprise Software, will really depend on the many decisions - such as trade agreements - that take place after a vote to leave.
But Broadhurst said his company, which is based in Bethlehem, Pa. and has locations worldwide, is opening an office in the UK for better access to the market. Whether the UK is in or out of the EU has no impact on that decision.
"High tech companies in the UK are tremendously against the exit," said Broadhurst. But since EU regulators do not always act in favor of tech companies, "It would be possible that the UK becomes a better place to be based than the EU," he said.
If recent surveys of UK tech leaders are accurate, most hope to remain in the EU. CompTIA recently surveyed 32 small to mid-sized businesses in the UK; 53% opposed an exit, 19% were in favor, with the remainder uncertain.
Polls of voters have shown the vote to be close, and neither side was certain of victory. Results from the vote are expected to roll in tomorrow evening in the U.S. after polls close in the UK.
There are worries about the broader economic impact of a yes decision. Brexit would reduce freedom of movement, said Phil Gibbs, a London-based executive director of customer success for LLamasoft, a supply chain software maker based in Ann Arbor, Mich.
"Many distribution operations in the UK are staffed by labor that originates from the continent, particularly within the Eastern European nations," said Gibbs via email. "If restrictions are placed on their ability to work in the UK, a labor shortage could emerge, leading to upwards pressure on costs."
Investment decisions by global companies are bound to be affected, as well, said Gibbs. "They will no doubt be modeling the impact of movements in costs, labor availability and trade restrictions on their supply chain before making decisions," he said.