Best Time to Book a Flight: How Far in Advance and Which Day Is Cheapest | By Kathryn Wortley | Publisher Lonely Planet

Over 9.8 billion people traveled by air in 2025, according to Airports Council International. That momentum has dipped in 2026 due to geopolitical tensions, airspace disruptions – particularly over the Middle East – and rising costs, but the billions of people who are still traveling are looking for good deals on their flights.

The travel industry – which includes airlines – has an 87% cart abandon rate, the highest of any sector, according to the financial services and software company Stripe. With myriad considerations, including price, availability, crowding and distance to travel, many travelers remain unsure of the best time to book flights. We asked the experts for their tips.

Check Flights Well in Advance

Kansai International Airport in Osaka, Japan. Cristi Croitoru/Shutterstock

It’s helpful to search for flights as they are released, which tends to be 11 to 12 months before departure for all flight types, according to online travel tool Autopilot.

“Booking as early as you can is recommended to help you to find a good deal. Airfares are tied to supply and demand, so prices are almost always cheaper when there are more seats available. As seats fill up, prices generally rise,” says Martin Nolan, Skyscanner’s Chief Legal Officer.

However, as airlines monitor demand closely, prices may drop as the departure approaches if fewer seats than anticipated are sold, such as on an off-peak travel day or less-used route.

Conversely, airlines adjust capacity for routes proving more popular or may even launch new routes. “This could mean another flight added for a busy peak season, a change to a different aircraft capacity or a flash seat sale,” says Nolan.

He recommends signing up for airlines’ email alerts and following their social media accounts to be among the first to know when new flights are released.

Book – and Travel – on a Friday

Aircraft at Suvarnabhumi Airport in Bangkok, Thailand. umitc/Shutterstock

There is a long-held belief that Tuesday is the best day for booking flights, as airlines typically release new fares on Mondays, but research from the online travel company Expedia debunks the idea entirely.

Expedia’s 2026 Air Hacks Report analyzed billions of flight data points. The company found that regardless of destination, the best day to book an international flight is Friday. It’s also around 8% cheaper to fly internationally on a Friday rather than a Sunday, which is the most expensive day.

The Best Booking Times Vary for International and Domestic Travel

If you’ve not been able to plan so far ahead, it’s still possible to find your ideal flight closer to departure, according to John Grant, Chief Analyst at global travel data provider OAG. He advises booking “5 months to 6 weeks before travel, when the airlines have a good idea about how demand is building and will stimulate some more booking activity.”

First, consider how far you’re traveling, and whether you are flying domestically or internationally.

Based on historic patterns, Skyscanner recommends booking 1 to 3 months ahead for short-haul flights (less than 3 hours) and 2 to 6 months out for long-haul flights (more than 6 hours).

Expedia’s 2026 Air Hacks Report considers the ideal booking window for an international flight to be 31 to 45 days in advance, rather than the previously estimated 6 months. Booking 8 to 14 days ahead of travel for international can offer the best value if travelers are willing to leave it that late. For domestic flights, 15 to 30 days in advance shows the strongest value.

Important factors when booking a flight include the popularity of the destination, your degree of flexibility on your travel dates, your preferred seat class and if you need a direct or connecting flight.