How we know: Sources are listed at the end. Policy details come from the cited guides' descriptions of US Department of Transportation rules; Wildly has no data on how often error fares occur.
An error fare (or mistake fare) is a price an airline never meant to publish: a business-class seat filed at an economy price, a long-haul fare missing its fuel surcharge, a currency conversion gone wrong. They are real, they are rare, and the rules around them changed in 2015 in a way that matters if you plan to book one.
Why error fares happen
Airline fares are filed as thousands of rules and prices distributed through industry clearing systems to every booking channel. Errors creep in at that filing step. One Mile at a Time lists the usual causes: a "fat finger" that drops a digit, a fare filed in the wrong cabin's bucket, a currency conversion error, and fuel surcharges accidentally omitted, which can be a large share of a long-haul ticket (One Mile at a Time). Because the fare propagates automatically, it can be bookable on the airline's own site and on agencies at the same time.
How long they last
Hours, usually. An error is typically noticed once bookings spike or a deal community posts it, and the airline withdraws the fare. Widely booked premium-cabin mistakes have become uncommon: One Mile at a Time puts them at "maybe one at most every several months" (One Mile at a Time). Economy mistakes on ordinary routes happen more often but are less dramatic.
Do airlines have to honor them?
In the US, not any more. Until 2015 the Department of Transportation required airlines to honor purchased fares even if they were obvious mistakes. In May 2015 the DOT changed its enforcement policy: an airline may cancel a mistaken fare provided it demonstrates the fare was a mistake and reimburses passengers for reasonable, verifiable out-of-pocket expenses made in reliance on the ticket (non-refundable hotels, tours, connecting flights, visa fees) in addition to refunding the fare (The Points Guy). Many airlines still choose to honor mistakes for goodwill, especially when the incremental cost is small, but you cannot count on it.
How to book one without getting burned
- Book directly with the airline when you can. It simplifies any refund and makes the DOT 24-hour rule cleaner: tickets bought at least seven days before departure can be cancelled within 24 hours for a full refund, a protection that applies to bookings made directly with the airline and is honoured by some, not all, agencies (Thrifty Traveler).
- Do not call the airline to ask if the fare is real. You will draw attention to it and get no useful answer.
- Wait for a ticket number, then wait some more. Do not book non-refundable hotels or connecting flights until the airline has honoured the fare or enough time has passed that cancellation is unlikely. If it is cancelled after you have booked such things, keep receipts; that is what the reimbursement policy covers.
- Pay with a card that offers dispute rights. The Points Guy notes DOT complaints are slow and rarely satisfying; a card dispute is the practical backup if an airline cancels and refuses to refund (The Points Guy).
- Keep it modest. One or two tickets. Booking six for the extended family increases the chance the airline decides the fare was clearly a mistake and cancels.
How to find them
There is no search trick that surfaces error fares on demand. What works is being in the flow of information when one appears:
- Deal communities and newsletters (Thrifty Traveler, Going, Secret Flying, the FlyerTalk Mileage Run forum) publish mistake fares within minutes of spotting them.
- A stretch price alert on the routes you care about, set well below the normal range, will fire if a mistaken fare lands on a date you can travel. It is a passive net, not a guarantee. Set one on a route such as JFK to Tokyo, LAX to Paris or Chicago to Sydney via price alerts.
- Be ready to book within minutes. Have your passport details and payment card to hand.
Is it ethical?
Reasonable people disagree. The airline made an error and has a legal path to correct it; you are accepting a published price in good faith. What is not reasonable is abusing the airline's staff, or booking non-refundable plans and then blaming the carrier when the fare is withdrawn. Book, wait, and treat it as a bonus.
FAQ
How often do error fares happen? Rarely for headline-grade premium fares; One Mile at a Time estimates one widely booked example every several months. Small economy mistakes are more frequent but less noticed.
Will the airline cancel my ticket? Possibly. Under current US DOT policy it may, provided it refunds you and covers documented out-of-pocket expenses.
Should I use points or cash on an error fare? Cash. Award mistakes are handled under the loyalty programme's terms, which are usually less protective.