How Far in Advance Should You Book Flights?

The shape of the curve

Airlines typically open seats around eleven months ahead. Those earliest fares are often not cheap, because there is no pressure to discount and the seats can be held for travellers who will pay more later. Booking the day a schedule opens rarely gets you the best price.

Prices then settle into a middle period where the discounted buckets are available and competition between carriers is doing most of the work. This is where the reasonable fares live, and it is wide — usually a span of months rather than a magic week.

In the closing weeks the cheap buckets sell out and the fare climbs, sometimes steeply. The rise is not a penalty for lateness; it is the cheap inventory being gone. The aim is to buy inside the middle period rather than to pinpoint its lowest day, which you cannot know in advance and will only identify afterwards.

Domestic trips

For an ordinary domestic trip, start watching roughly one to three months out. Routes with many daily flights stay competitive later, because there is more inventory and more scope for carriers to undercut each other.

Bring that forward for anything with concentrated demand: public holidays, school breaks, a major event in the destination city, or a thin route with only one or two flights a day. On a thin route the cheap seats are a small absolute number and can be gone months ahead.

International trips

Two to six months is a sensible monitoring range for most international travel. Long-haul routes have fewer daily departures than domestic ones, so each fare bucket holds fewer seats and sells out sooner in relative terms.

Push earlier for peak season on a popular leisure route, for premium cabins where the discounted inventory is genuinely scarce, and for trips built around a fixed onward connection such as a cruise departure or an internal flight booked separately.

Let the cost of being wrong set the timing

The more useful question is not when fares are lowest but what happens if you wait and the price rises. If several dates work and you could postpone by a fortnight without much consequence, waiting costs you little and you can afford to watch.

If the trip exists to attend something — a wedding, a cruise, a visa appointment, a funeral — the cost of a fare rising is that you pay it anyway, because you have to travel. In that situation book earlier at a price you find acceptable and stop watching. Holding out for a saving you may not get, on a trip you cannot cancel, is a poor trade.

• Set alerts rather than repeating the same search each day.
• Note what a normal fare looks like, so you can recognise a good one.
• Read the change rules before buying a restrictive ticket far ahead.
• Do not plan around a late price drop for a trip with a fixed date.

Booking early has its own risks

Buying eight months out has a cost that fare charts do not show. Airlines adjust schedules regularly, and a flight booked far ahead may be retimed, rerouted or cancelled outright. You are usually entitled to a rebooking or refund, but it means handling a change to a trip you thought was settled.

The further ahead you book, the more likely your own plans shift too. If there is real uncertainty about the dates, weigh a slightly higher fare with reasonable change terms against a cheap restrictive one, because changing a restrictive ticket often costs more than the original saving.

Award tickets run on a different clock

If you are booking with points rather than cash, the timing advice inverts. Award availability is usually released when the schedule opens, in small quantities, and the best redemptions are taken quickly by people watching for them. Waiting is rarely rewarded.

For award seats in premium cabins, or for several people travelling together, booking close to the schedule opening is often the only realistic approach. Some airlines release additional award space closer to departure when a flight has not sold well, but that is opportunistic rather than something to plan a trip around.

A practical way to decide

Work backwards from the trip. Fixed and unmovable, or peak season: book toward the early end of the range, once you have watched long enough to know a normal price. Flexible on dates, off-peak, well-served route: watch into the middle period and buy when something suitable appears.

In both cases set a figure you would accept before you start, and buy when you see it. That converts an open-ended search with no natural end into a decision you can actually make.