It was touch and go for a few hours in early January as customers waited to find out whether Cathay Pacific Airways would honour the first and business-class tickets they had bought at economy-class prices . Several thousand tickets are believed to have been sold during the computer error, which was blamed on an employee entering the wrong fares into the company’s system for flights between Vietnam and North America. For a few hours, a ticket from New York City to Da Nang, for example, cost US$675 instead of US$16,000. Customers who had paid the cheap fares breathed a sigh of relief when the airline tweeted, “Happy 2019 all, and to those who bought our good – VERY good surprise ‘special’ on New Year’s Day, yes – we made a mistake but we look forward to welcoming you on board with your ticket issued. Hope this will make your 2019 ‘special’ too! #promisemadepromisekept #lessonlearnt” Mistake fares are lovely surprises that occur for a number of reasons, says Scott Keyes, the United States-based founder of Scott’s Cheap Flights, who likes to boast that he once travelled to Milan from New York for US$130 round trip because of one such blunder. “It can be caused by human error or by a fat-finger discount,” Keyes says. He thinks his Milan fare probably was supposed to be US$1,300 – but because of a misreading or a slip of a finger, a zero was omitted, shaving US$1,000 off the cost of his ticket. This also happened in 2007, when customers were able to score a business-class flight from San Francisco to New Zealand for US$1,500 rather than US$15,000. Happy 2019 all, and to those who bought our good - VERY good surprise ‘special’ on New Year’s Day, yes - we made a mistake but we look forward to welcoming you on board with your ticket issued. Hope this will make your 2019 ‘special’ too! . #promisemadepromisekept #lessonlearnt — Cathay Pacific (@cathaypacific) January 2, 2019 Currency conversion errors (in 2012, a flight from Myanmar to the US was US$300 because of a currency conversion mistake), an algorithm (in 2013, some people snagged flights to Hawaii from the US mainland for US$7 round trip because of a computer glitch) and other human errors (programmers may forget the fuel surcharge, for example) can lead to these mistakes. Until 2015, the US Transportation Department required all airlines to honour mistake fares; now the government simply requires airlines to refund mistake fares and reimburse would-be passengers for cancellation fees if they bought that fare and then tacked on hotels, excursions and other travel plans. Still, Keyes says, almost all the airlines continue to honour their mistake fares. “If they cancel the tickets, they have thousands of irate customers,” Keyes says. “Those folks vent about it on social media, and it becomes a huge PR nightmare.” Not only do those mistakes sometimes fly (pun intended), but occasionally the airlines even use the mistakes as a PR plus. Just as Cathay would a few months later, in August last year, Hong Kong Airlines owned a mistake it had made. When honouring US$600 round-trip business-class tickets from the US to Asia, the airline handed out cards to the fortunate recipients that read, “As one of the lucky few to get that deal of a lifetime … we would love to see some of your photos on-board.” The airline received plenty of Instagram love. Chief marketing officer George Liu later tweeted, “No, it wasn’t intentional … definitely not a marketing gimmick. We really screwed up. It hit when I was BBQing at a friend’s house on my vacation. We have decided to honour the tickets at our own cost. We are willing to pay a price to keep our promises as a brand.” Lucky passengers. Or is there more to snagging a mistake fare than just luck? Here’s how to increase your chances of finding them or other super-low fares. Pay for membership to special deal sites. Dale Johnson, co-founder of Nomad Paradise, has scored deals like New York to Johannesburg round trip for less than US$200 because he pays for memberships to Scott’s Cheap Flights and Flystein, which send deals to him often. Sometimes these are mistake fares, and other times they’re simply particularly good deals. Set up price alerts. Google Flights and Kayak will let you know when a flight has dropped below the rate you set, Johnson says. In this case, you’d have to set a price alert for a specific route rather than waiting for a random deal – but if there is a mistake or a very good deal offered on your route, you’ll be the first to know about it. Sign up for daily alerts . There are a few newsletters/email alerts focusing on mistake fares, says Sophie Anderson, founder of the Wanderful Me, a vegan travel and adventure blog. Her favourites: Secret Flying, Airfarewatchdog, the Flight Deal and FlyerTalk Mileage Run Deals. Follow apps that do not send alerts at set times (check the fine print to see whether you’ll get instant alerts). If a travel company is offering a daily price alert at the same time every day, then you are going to miss some great deals, says Brianna Schneider, a spokeswoman for Hopper, a travel-booking app. Instead, you want to follow apps such as Hopper, Scott’s Cheap Flights or Skyscanner, which monitor the prices all day every day via algorithms that detect mistake fares instantly. These apps will alert users via a push notification immediately, because the mistake fares don’t last long and can happen at any time, Schneider says. Click “see first.” A little-known option on Facebook is to use the “see first” button so you can prioritise which friends or pages you want to see first when you open Facebook. Use this for the mistake fare pages you follow so you are more likely to see them as soon as they post a deal. The lucky people in front of Facebook when the deal is posted will be able to snag it. Book through the airline’s website , not a travel agency. Travel agencies tend to make a request for the ticket. This takes time, and during these precious hours, the mistake fare may disappear. If you book without a middleman, you’ll snag the deal faster and get your ticket in your inbox – which usually means it’ll be honoured, Keyes says. Don’t hesitate. US federal law states that if you book a flight directly with an airline and are at least a week out from travel, the airline must give you 24 hours to cancel without penalty, Keyes says. So book the flight even if you aren’t completely sure about the dates; just make sure you check the dates and make a final decision within 24 hours. While the law only applies to US airlines, most airlines outside the country also have a 24-hour penalty-free cancellation policy. Focus on North America and Europe . Flights departing from North America and Europe typically see the largest number of fare errors, simply because the higher the number of flights, the more chances of mistakes, says Tarik Allag, founder of Secret Flying. “Additionally, flights which have multiple airlines operating on the same ticket are more susceptible to becoming error fares,” Allag says, explaining that fuel charges are added after commercial airline reservation systems are created, and this often leads to errors on the airline’s complex, outdated systems. When more than one airline is present on the same ticket (in other words, when flights are booked through one airline but operated by another carrier), these types of glitches occur more frequently. Although there aren’t particular airlines that stand out in terms of having the most frequent error fares, a few years ago, United Airlines was flubbing fares about every few days over a two-week period, Allag says. Search for flights through a VPN . A virtual private network allows you to browse the internet anonymously from anywhere – so you can essentially log in from another country, says Johnson, of Nomad Paradise, an online guide to travelling the world as a digital nomad. “Due to exchange rates, booking flights in some countries is far cheaper than others,” he says. When he needed to fly from Singapore to Denpasar, Indonesia, Johnson tried several countries, and when browsing from Thailand, some of the flights were up to US$200 less (it’s not technically a mistake, but this trick lowers the price to mistake fare levels). First, you have to purchase and download a VPN. (Johnson recommends Express VPN, which costs US$9.99 for the monthly plan.) Next, clear your cookies so that the sites cannot detect your strategy. You will also need to find a website in the country you want to search from. For example, if you are using a VPN for an IP address in Spain, you’ll need to go to Expedia.es instead of Expedia.com. Some recommended countries to search “from” are Argentina and Russia, which tend to offer lower fares than other countries. Be aware of currency devaluation . Sometimes, when there’s an overnight currency devaluation, it can be really inexpensive to book a flight in a foreign country when all the systems haven’t caught up to the exchange rate change, Keyes says. It wouldn’t technically be a mistake fare, but it can save a lot of money. For example, in 2012, when Myanmar’s government stopped pegging its currency to the US dollar, causing its value to plunge virtually overnight from 6 kyat per dollar to 800 kyat per dollar, travellers were able to book business- and first-class flights out of Yangon that had previously been more than US$10,000 for as little as US$250, Keyes says. Text: The Washington Post Additional reporting: Staff Writer