It is also unclear how travelers will pay the fee, the U.S. Travel Association told CNBC.

“The bill directs the DHS Secretary to charge the fee, but DHS does not own the visa application, issuance or renewal process — so where and when would DHS collect the fee?” the spokesperson said.  

In response to CNBC’s enquires, a Department of Homeland Security spokesperson said: “The visa integrity fee requires cross-agency coordination before implementation.”

More questions surround how and when the reimbursement process kicks in.

Since many visas are valid for several years, the U.S. Congressional Budget Office said it expects “a small number of people would seek reimbursement.”

Moreover, “CBO expects that the Department of State would need several years to implement a process for providing reimbursements. On that basis, CBO estimates that enacting the provision would increase revenues and decrease the deficit by $28.9 billion over the 2025‑2034 period.”

Brown said he is advising clients to treat the fee as nonrefundable.

“If you get it back, great. But it is usually difficult to get money back from the government,” he said. “I would rather them view it as a ‘bonus’ if they get the refund.”

“President Trump’s One Big Beautiful Bill provides the necessary policies and resources to restore integrity in our nation’s immigration system,” a Department of Homeland Security spokesperson told CNBC.

Data shows most visa holders comply with their visa terms. For the fiscal years between 2016 and 2022, between 1%-2% of nonimmigrant visitors overstayed their visas in the United States, according to the U.S. Congressional Research Service.

However, an estimated 42% of the approximately 11 million unauthorized population living in the United States entered the country legally, but overstayed their period of admission, the data shows.

Brown said the visa integrity fee will likely impact B visa holders — or leisure and business travelers — and international students more than other types of travelers.

“For B visa holders, they may not want to add an additional $250 per person to their trip costs,” he said.

The new fee, plus the I-94 fee, come as the United States prepares to host several major events in 2026, including the “America 250” celebration, in honor of the country’s 250th anniversary, and parts of the FIFA World Cup.

These hurdles are compounded by problems at Brand USA, the destination marketing organization that promotes inbound travel into the United States, which saw the One Big Beautiful Bill Act slash its funding from $100 million to $20 million.

The cuts came after the U.S. Commerce Department fired nearly half of Brand USA’s board members in April.

In a statement, Fred Dixon, the organization’s president and CEO, said it is “disappointed” with the cuts yet hopeful that the funds will be restored for the fiscal year 2026.

“We remain focused on growing legitimate international inbound travel and the vital boost it provides to the U.S. economy,” he said.

Ahead of the passage of the One Big Beautiful Bill Act, U.S. Travel Association President and CEO Geoff Freeman praised the bill’s contributions to U.S. infrastructure, air traffic control and border security.

But, he added: “The smart investments in the travel process make foolish new fees on foreign visitors and reductions to Brand USA, America’s promotion arm, that much harder to swallow.”

— CNBC’s Kaela Ling contributed to this report.

Update: This story has been updated to reflect Brand USA’s comments to the funding cuts to its organization.