Every so often, an airline publishes a fare that's wildly wrong. A business-class seat to Asia for the price of economy. A transatlantic return for less than a train ticket. For a few hours, anyone who spots it can book it. Then the question becomes: will the airline actually let you fly?
In Canada, the honest answer is "maybe, and it depends on how obvious the mistake was." Here's how these fares happen, how to catch one, and what the rules say when an airline tries to take it back.
What is a mistake fare?
A mistake fare (or error fare) is a ticket sold at a price the airline never meant to offer. It's different from a sale. A sale is a low price on purpose. A mistake is a price nobody at the airline approved, and it usually disappears within hours once someone notices.
How do they happen?
- Currency slips. A fare meant in one currency gets published in another, or the conversion goes wrong. In 2015, United sold first-class tickets from the U.K. to the U.S. for a tiny fraction of the real price after a currency error on its Danish website.
- Missing pieces. Airline fares are built from parts: a base fare, fuel surcharges, taxes. If a surcharge drops out of the calculation, the total can fall by hundreds of dollars.
- Plain typos. People file fares by hand. A missing zero turns $1,500 into $150.
- Glitches between systems. Fares pass through several companies' systems before you see them, and a bug anywhere along the chain can produce a price that doesn't make sense.
Do airlines have to honour them in Canada?
No, not automatically. Canada has no law that forces an airline to honour a price published by mistake.
The key case is a 2014 decision by the Canadian Transportation Agency (Decision No. 202-C-A-2014). Swiss International Air Lines had sold first- and business-class tickets from Yangon, Myanmar, to Montreal, Toronto and Ottawa for a total of about US$1,000, taxes included. The real fares were US$10,000 to US$15,000. Swiss cancelled the tickets and refunded 83 passengers, who complained that a deal is a deal.
The Agency sided with the airline. Its reasoning: a reasonable person ought to have known that a first-class ticket from Asia to Canada for about US$1,000 wasn't just a low price but a mistake. When the price is a fundamental part of the contract and the buyer should have known it was wrong, there's no real agreement, and the airline can cancel and refund.
The practical takeaway: the more absurd the fare, the less protection you have. A fare that's 40% below normal might just look like a great sale. A fare that's 90% below normal, in first class, is going to be very hard to hold an airline to.
What about flights to and from the U.S.?
The U.S. has a rule that stops airlines from raising the price of a ticket after you've paid for it. But in 2015 the U.S. Department of Transportation said it would not enforce that rule against genuine mistake fares, as long as the airline refunds the ticket and reimburses the traveller's reasonable, provable out-of-pocket costs, such as non-refundable hotel bookings or tours booked because of the ticket.
So on U.S. routes, even when the airline cancels, you shouldn't end up out of pocket for what you spent in good faith. Keep every receipt.
How to catch one
- Be ready to book fast. Mistake fares often last a few hours. Know your dates, keep your passport details handy, and don't wait until tomorrow to decide.
- Follow deal alerts. Nobody finds these by casually searching. Deal sites and newsletters spot them and share them quickly.
- Book directly with the airline when you can. If the fare survives, you'll deal with one company instead of two when something changes.
How to protect yourself after booking
- Don't call the airline to ask whether it's a mistake. You're only drawing attention to your booking. Wait for them to contact you.
- Hold off on non-refundable plans. Wait a week or two before booking hotels, tours or connecting flights you can't cancel. Most cancellations happen in the first few days.
- Pay with a credit card. If a refund stalls, a credit card gives you a way to dispute the charge.
- Keep screenshots. Save the price, the fare rules and your confirmation email. If there's ever a dispute, you'll want proof of exactly what you were sold.
Is it ethical to book a mistake fare?
It's a fair question. Booking a price the airline published isn't a trick; you're buying what was offered. But when a fare is so low that you know it's a mistake, that's exactly the situation where Canadian regulators have said the airline can cancel. Go in expecting it might be taken back, and treat it as a bonus if you fly.
Not legal advice. This is a plain-language summary of published decisions and policies as of September 2026. Rules change and every case is different; if a lot of money is at stake, check the airline's tariff and speak to a lawyer or the Canadian Transportation Agency.
Most great fares aren't mistakes; they're ordinary seats priced well below normal. OddFare finds those every day for flights out of Toronto. See today's deals.