You would think that airlines would fill empty seats by slashing prices at the last minute. But even with a near empty cabin, airlines very rarely lower prices in the eleventh hour.
Part of the reason is human behavior. If airlines lowered prices last minute, consumers would likely catch on and that's not exactly profitable for the airline, says Jack Sheldon, who considers himself something of an expert at finding flight deals. Sheldon runs a travel alert blog called Jack's Flight Club, where he claims he can help travelers save an average £402 per ticket, or $531.
What airlines facing empty flights often do instead is increase the price of their flights once the takeoff date gets closer. That's because the consumers most likely to book a flight at the last minute are business people whose travel expenses are covered by their company, says The Points Guy editor-in-chief Zach Honig.
For example, Honig has found connection or long-haul international flights that don't go to business centers to be cheaper at the last minute. Honig added that these could be "least expensive just a day or two before departure, especially on routes that aren't popular with business travelers."
And one thing not to do if you're looking to save money on airfare is book a non-stop domestic flight. Those flights typically increase in price significantly beginning 14 days before departure, Honig said.
So when is the best time to actually book a flight that won't break the bank?
Probably three to four weeks ahead of time, says Sheldon, for domestic flights. For popular international routes, consumers should start looking two to three months out. And if your schedule is flexible, book a flight that runs in the off-season—during the spring or in the autumn.