LONDON — For travel bargain hunters, the first day of 2019 was a spectacular one.
On routes between Asia and North America, Cathay Pacific, the Hong Kong-based airline, offered seats in its exclusive business and first classes for less than the economy fare. A round-trip flight in business class from Vietnam to New York cost as little as $674.63, a small fraction of the usual price, according to One Mile at a Time, a travel blog that documented the fares.
“Cathay Pacific does actually do some quite aggressive fare sales from Asia,” said Rob Burgess, the editor of a frequent flier website, headforpoints.com. Business class seats from Asia to the United States can be found for around $5,000.
But not this aggressive.
The low prices, offered by mistake for several hours on Monday in North America, caught Cathay Pacific itself by surprise.
On Wednesday, the airline acknowledged the error but said it would honor the fares. On Thursday, the trip that had briefly cost less than $700 appeared on the Cathay Pacific website for about $16,000 for a fully flexible fare.
Mr. Burgess said that ticketing errors happen often when airlines deal with bookings to hundreds of destinations and in dozens of currencies. These processes work automatically but, “somewhere in the system there’s a human typing a number in,” he said, which can lead to mistakes like mixing up currencies or leaving a zero off a price.
Cathay Pacific did not say how many people had been quick enough to take advantage of the accidental bargain.
“Yes — we made a mistake but we look forward to welcoming you on board with your ticket issued,” the airline wrote on Twitter, with the hashtags “#promisemadepromisekept,” and “#lessonlearnt.”
Airlines tend to catch such glitches in a matter of hours, leaving the opportunity open to only the most up-to-date shoppers. Carriers that do not honor such tickets refund the purchase prices, so there is little downside to snapping them up.
“These tickets are always booked by the same people,” Mr. Burgess said — travel enthusiasts who, he said, often monitor travel websites obsessively. ”There’s no risk at all as long as you are smart enough not to book a hotel” or other nonrefundable travel associated with the tickets.
A competing carrier, Hong Kong Airlines, made a similar mistake last August, selling $600 business-class seats on flights from Asia to North America. The airline honored the fares, possibly setting an example for Cathay Pacific to follow, travel writers commented.
For Cathay Pacific, this wasn’t the first glitch in the past year. In October, the airline said a data breach had exposed the personal details and travel histories of as many as 9.4 million people.
While the airline has so far kept the cause and cost of the glitch quiet, the mistake may result in a six-figure loss or more, The South China Morning Post reported. Along with the tickets themselves, the rare bargain included the accompanying mileage credit, giving buyers discounted credit toward frequent flier status, with lounge access and other benefits.
Cathay Pacific, known for its long-haul routes from its hub in Hong Kong, is regularly rated among the world’s best airlines. Its flatbed business and first-class seats with big-screen entertainment and fine dining have received praise from frequent travelers. But the carrier has been facing growing competition in Asia and recorded losses in 2016, 2017 and the first half of 2018.