Yes, in 2026, a 12-year-old can technically travel abroad alone, but they are subject to the Unaccompanied Minor (UM) policies of the airline and the entry requirements of the destination country. Most major airlines, such as American, Delta, and United, mandate that children aged 5 to 14 traveling without an adult must use their UM service, which involves a fee (often $150+) and ensures the child is escorted by staff from check-in to the receiving adult at the destination. At 12, a child is often in a "grey area" where some international carriers consider them "Young Passengers" who can travel without an escort but still require a notarized Letter of Consent signed by both parents. In 2026, UK and EU border authorities are especially strict; a 12-year-old flying alone into London, for example, would need clear documentation of who is meeting them and where they are staying to satisfy Border Force. While possible, it requires significant pre-planning, specialized "UM" bookings, and a mountain of legal paperwork to ensure a safe and legal journey.