For a 2026 trip from the UK to New York, you need a valid British Passport (ideally with at least 6 months remaining) and an approved ESTA (Electronic System for Travel Authorization). The ESTA is a visa waiver for tourists staying less than 90 days and costs approximately $21 USD. You must apply for the ESTA online at least 72 hours before your flight, and once approved, it is valid for two years (or until your passport expires). If you plan to stay longer than 90 days, or if you are traveling for work or study, you will need a formal B1/B2 Visitor Visa, which requires an interview at the US Embassy in London or the Consulate in Belfast. As of 2026, there are no longer COVID-19 vaccination or testing requirements for entry, but you should always double-check the latest "Customs and Border Protection" (CBP) declarations for any items you plan to bring into the United States.