Starting January 8, 2026, U.S. citizens traveling to the United Kingdom will require an Electronic Travel Authorization (ETA). This digital permit, similar to the U.S. ESTA system, must be obtained online before travel for tourism, business, or transit. The ETA will be valid for two years or until the passport expires, allowing multiple entries. The application fee is £16 (approximately $22), and the requirement extends to citizens of nearly 50 other countries, including Canada, Mexico, Australia, and Brazil.