Mistake Fares: What They Are, How to Find Them, and Whether They'll Be Honored

April 30, 2026

In 2012, United Airlines briefly sold business class tickets from the US to Hong Kong for $43 return — a "mistake fare" caused by a currency conversion error that left taxes and fees in New Zealand dollars rather than US dollars. Thousands of people booked before the fare was pulled. United honored almost all of them. The passengers flew business class to Hong Kong for $43.

Mistake fares are real. They're not mythological. They happen regularly enough that communities of fare watchers have built entire websites around finding them. Understanding what they are, why they occur, and what your rights look like if one gets canceled is genuinely useful knowledge for anyone who flies frequently.

What Is a Mistake Fare?

A mistake fare is a flight ticket priced significantly below its intended price due to a human or technical error during the fare-loading process. Airlines and OTAs load enormous numbers of fare rules into their systems at any given time, and the process is complex enough that errors occur regularly. Common causes:

Currency conversion errors (the most dramatic, like the United HKG example). A fare entered in one currency gets converted incorrectly, producing a price that's a fraction of intended.

Missing fuel surcharge. Fuel surcharges are typically loaded separately from base fares. When the surcharge layer fails to attach, you get a ticket priced only on the base tariff — which can be extremely low.

Transposition errors. A human data entry error turns £1,200 into £120 or €890 into €89. These can persist for hours before being caught.

OTA glitches. Sometimes the error isn't at the airline level at all — it's a third-party booking platform that has miscalculated or misapplied a promotional discount, creating a sub-floor price that the airline never authorized.

How Long Do They Last?

Most mistake fares survive for minutes to hours before being caught and corrected. The window depends on how much traffic the route normally receives and how quickly the airline's revenue management team monitors outlier bookings. A domestic US route with high booking volume might trigger an alert within 20 minutes. A niche international route with low booking frequency might persist for several hours.

This is why communities that track mistake fares maintain alert systems: you need to act within minutes or the window closes.

Where to Find Them

The most reliable mistake fare sources are community-driven:

Secret Flying (secretflying.com) is the most comprehensive aggregator of reported mistake fares globally. It lists current and recent confirmed mistake fares with booking links and notes on validity.

Scott's Cheap Flights (now Going.com) covers US-based mistake fares and genuine error fares with a paid tier that alerts faster.

Reddit's r/flightdeals and r/churning communities often surface mistake fares before aggregator sites, because individual members are watching specific routes or airlines.

Airline direct sites occasionally produce their own errors that don't appear on OTAs — particularly when fare rule updates fail to propagate correctly. This is why it's worth checking directly if you hear about a suspected error.

Will the Airline Honor the Fare?

This is the most important question, and the answer varies significantly by jurisdiction and airline.

In the United States, the Department of Transportation (DOT) rules are relatively consumer-friendly: airlines are generally expected to honor tickets that have been purchased and confirmed. DOT guidance has historically leaned toward enforcement of mistaken fares, particularly if the airline has already issued a booking confirmation. Airlines can petition for an exception if the error is "obvious" — but the threshold for what qualifies as obvious is contested.

In the UK and EU, the situation is more nuanced. The Civil Aviation Authority (CAA) doesn't have an explicit rule requiring honor of mistake fares. However, consumer contract law applies: once a booking confirmation is issued, a contract has been formed, and canceling it may require compensation (a refund plus potentially additional damages). Several UK cases have resulted in airlines honoring mistake fares rather than facing consumer law challenge.

Australian consumer law provides some of the strongest mistake fare protections globally — airlines have been required to honor clearly mistakenly priced tickets that were already confirmed.

Practically: if you book a mistake fare and the airline tries to cancel it, file a complaint immediately with your jurisdiction's aviation regulator. Keep all confirmation emails. Don't contact the airline proactively before flying.

How to Book a Mistake Fare

When a mistake fare appears:

1. Book directly with the airline if possible, not through an OTA. Airline direct bookings produce contracts directly with the carrier, which is cleaner for enforcement purposes.

2. Book on a credit card, not debit. If the airline cancels and refuses to refund, your credit card company may provide chargeback protection.

3. Don't plan beyond the booking until the fare has been booked for 24 hours without cancellation notice. Don't book non-refundable hotels.

4. Check for the "24-hour free cancellation" rule: in the US, airlines are required to allow free cancellation within 24 hours of booking. If you're uncertain whether the fare is real or mistaken, you can book and cancel within 24 hours with no financial exposure.

The Difference Between a Mistake Fare and Just a Cheap Fare

Not all very cheap fares are mistakes. Airlines run genuine sale fares, flash sales, and seat-fill discounts that look remarkably similar to mistake pricing. The tells that suggest an actual error rather than an authorized sale:

The fare appears on the airline's own website but not in any official promotional communication. Genuine sales are marketed; mistake fares aren't.

The route has no historical precedent for the price point. If a business class ticket from London to Tokyo has never been below £1,200 and is suddenly showing at £180, that's a signal.

The fare disappeared within hours. Authorized sales are typically live for days.

RegionFare and Systematic Price Monitoring

Regional price differences across booking markets can look like mistake fares but are often legitimate. A flight that costs £340 in the UK market and £265 in the Israeli or South African market isn't a mistake — it's the airline applying regional pricing strategy, as covered in other articles here. RegionFare surfaces these systematically, which means you see prices that are genuinely low without the enforcement uncertainty of a mistake fare.