Whether you need a transit visa for a layover in 2026 depends on three main factors: your citizenship, your destination, and whether you plan to leave the airport's international zone. Many countries, such as Singapore or the UAE, allow most nationalities to stay in the international transit area for up to 24 hours without a visa. however, some nations have "Direct Airside Transit" rules that require a visa even if you never pass through immigration—notably the UK and the USA (which has no "international transit" and requires an ESTA or visa for all). If your layover requires you to change airports (e.g., from Tokyo Haneda to Narita) or if you book two separate tickets where you must collect and re-check bags, you will almost certainly need a transit or standard visitor visa to pass through border control. Additionally, "Schengen" transit rules in Europe can be complex, requiring specific nationalities to hold an "Airport Transit Visa" (Category A). Always check the official consulate website of the transit country at least 30 days before travel, as airline staff are required to deny boarding to anyone without the correct transit documentation.