For a short-haul flight with hand luggage, arriving 2 hours before departure is usually enough at Heathrow. For long-haul, Heathrow advises 3 hours, and 2 hours is tight once you factor in bag drop, the morning security peak and the walk to a distant gate. If you are checking bags or flying at peak, give yourself 3 hours. Checked August 2026.
What Heathrow actually advises
Heathrow's own guidance is to arrive 3 hours before a long-haul flight and about 2 hours before a short-haul or domestic one. Those numbers exist because international departures involve more steps than a quick domestic hop: bag drop, security, sometimes a long walk to the gate, and a boarding process that closes well before departure. So the honest headline is that 2 hours is the short-haul figure, not the long-haul one.
The four things that eat your two hours
Whether 2 hours works comes down to how much time each stage takes on your day.
Bag drop is the first constraint. If you are checking a bag, you must reach the desk before the airline's cut-off, which is often around 60 minutes before a long-haul flight and can be earlier. If you arrive 2 hours out but spend 30 minutes reaching the terminal and finding the desk, you can still make it, but there is little slack if anything goes wrong. Travelling with hand luggage only removes this constraint entirely and is what makes 2 hours comfortable on short-haul.
Security is the second. The good news is that it is usually fast: over 97 per cent of passengers cleared Heathrow security in under five minutes across 2025, helped by the new CT scanners in all four terminals. The exception is the morning long-haul peak, roughly 05:00 to 08:00, at T3 and T5, where waits can exceed 20 minutes. If your flight is in that window, build in the extra time.
The walk to the gate is the third, and it surprises people. Heathrow's terminals are large, and some gates are in far piers or satellites a long way from the main lounge, which can be a 10 to 15 minute walk or more. Boarding, the fourth stage, then closes before departure, often 30 to 45 minutes ahead, so your usable time is less than the clock suggests.
When 2 hours is fine
Two hours is generally enough if several of these are true: you are on a short-haul or domestic flight, you have checked in online, you are travelling with hand luggage only, and you are flying outside the morning peak. In that case you walk in, clear a quick security lane and go straight airside with time to spare.
When to make it 3 hours
Give yourself 3 hours if you are flying long-haul, if you are checking bags, if you are travelling at the morning peak, if you are in a large group or with children who slow the process, or if you need special assistance. The cost of arriving early is a longer wait airside, where there are shops, food and lounges. The cost of cutting it fine is missing a bag-drop cut-off or a boarding gate, which can mean missing the flight, so the trade is not symmetrical.
Terminal and transfer traps
Two extra things can undo a tight plan. First, make sure you go to the right terminal: some British Airways long-haul routes moved from T5 to T3 in 2026, so check your flight's terminal in advance with our guide to finding your Heathrow terminal. Arriving at the wrong terminal can cost you 30 to 60 minutes on a transfer. Second, if you are connecting rather than starting your journey here, the timings are different again, so see our guide to connection times at Heathrow.
The bottom line
If you want a simple rule: 2 hours for short-haul with hand luggage, 3 hours for long-haul or whenever you are checking bags or flying at peak. When in doubt, err towards the longer figure, because the downside of being early is only a longer coffee.
More
More: Overview, Facilities, FAQs.
Frequently asked questions
Is 2 hours enough at Heathrow for an international flight? For short-haul with hand luggage, usually yes. For long-haul, Heathrow advises 3 hours, and 2 hours is tight once you add bag drop, the morning security peak and the walk to a distant gate. Allow 3 hours if you are checking bags or flying at peak.
How early does Heathrow tell you to arrive? Heathrow advises arriving 3 hours before a long-haul flight and about 2 hours before a short-haul or domestic one.
What time is security busiest at Heathrow? The morning long-haul peak of roughly 05:00 to 08:00 at T3 and T5 is the busiest, when waits can exceed 20 minutes. Outside that window, over 97 per cent of passengers cleared security in under five minutes across 2025.
When should I allow 3 hours at Heathrow instead of 2? Allow 3 hours for long-haul flights, when checking bags, at the morning peak, in a large group or with children, or if you need special assistance.
Do I need to worry about the walk to the gate at Heathrow? Yes. Some gates are in far piers or satellites a long way from the main lounge, a 10 to 15 minute walk or more, and boarding closes before departure. Leave time to reach the gate after security.
We recommend a transport partner and may earn a referral fee. It never changes what you pay, and we only list options we would use ourselves.
Last verified August 2026 by the Heathrow Airport Guide editorial team. Prices and timetables change, so confirm the specifics on the official Heathrow Airport website before you travel.