For a "self-transfer" flight in 2026—where you book two separate tickets and are responsible for collecting and re-checking your own bags—it is professionally recommended to allow at least 4 hours between flights. This buffer accounts for the time needed to clear passport control, wait for checked luggage at the carousel, transfer between terminals (which can take 20–30 minutes at hubs like Heathrow or Changi), and clear security again for your second flight. If you are traveling with carry-on only and within the same terminal, you might manage with 2.5 hours. However, because the airlines are not obligated to rebook you if the first flight is delayed, a 4-hour window is the "safe" standard. Many 2026 travelers also opt for "Self-Transfer Insurance" or "Guarantee" products through booking sites like Gotogate or Kiwi, which provide protection if a delay causes you to miss your second independent leg.