In 2026, whether you need a visa for London depends entirely on your nationality. For Indian passport holders, a Standard Visitor Visa is mandatory for tourism or business trips of up to six months. As of February 25, 2026, the UK has officially transitioned to e-Visas for Indian nationals, meaning you no longer receive a physical sticker in your passport; instead, your visa is digitally linked to your passport number. For U.S., EU, and Australian citizens, you do not need a visa for short trips, but in 2026 you MUST apply for the UK ETA (Electronic Travel Authorisation) before departure. This is a small digital fee and registration similar to the US ESTA. Regardless of your visa status, your passport must be valid for the duration of your stay. For 2026 travelers, the "pro-tip" is to ensure your passport details in your UKVI (UK Visas and Immigration) account are perfectly current, as airlines will verify your digital status during the check-in process.