The following guide applies to all UK and EU citizens, including those from Ireland, Norway, Switzerland, and Croatia will need a valid passport to enter the U.S. for short visits. Under the Visa Waiver Program, most UK travellers hiring a campervan in New York can stay for up to 90 days with an approved ESTA, which must be applied for at least 72 hours before departure. If you are not eligible for the VWP, you will need a B-1/B-2 visitor visa. On arrival, U.S. Customs and Border Protection may ask about your trip, so be prepared to show proof of onward travel, accommodation, and sufficient funds. For the latest guidance, consult the official U.S. government website: official U.S. government website before traveling.