As travel demand continues to surge post-pandemic, so does the chaos surrounding it.

People who need short-term visas to visit Europe are encountering monthslong delays that threaten their travel plans, The New York Times reported.

Although most travelers from the U.S. don’t require visas to enter Europe’s Schengen Area — the border-free zone permitting free movement among 27 European countries — for up to 90 days, citizens of Turkey and several other countries, including India and China, must apply for visas for shorter stays, per the Times.

Starting early next year, all U.S. tourists visiting Europe will need a travelers visa called the European Travel Information and Authorization System (ETIAS). It will be a requirement for tourists from Canada, Australia and New Zealand as well.

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Since 2009, Schengen states have relied on third-party processing companies like BLS International and VFS Global to conduct initial screenings of candidates before completing the final step of issuance themselves, according to the outlet. But the available resources aren’t enough for soaring demand.

“Revenge tourism,” where higher flight and hotel costs don’t faze eager post-pandemic travelers, was in full swing this summer, AP News reported, complete with two-plus-hour waits to visit the Acropolis in Athens and crowds so thick around St. Mark’s Square in Venice that the city’s bridges are backed up even on weekdays.

Thirty-six-year-old Duygu Yildirim, an assistant professor who holds a Turkish passport and lives in Knoxville, Tennessee, told the Times she’d applied for at least 10 Schengen visas in recent years — so is all too familiar with the cumbersome, expensive process. Each application costs about $85.

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After Yildirim received an official invitation to a workshop in Belgium, the country’s consulate asked her for additional financial documents, including tax forms. “I am going on an invitation and they want to see my monthly bank statements?” Yildirim said. “They want to be sure that I’m not illegally immigrating there, just because I’m Turkish. It feels kind of strange, and humiliating, to ask how much money do you make.”