Wizz Air could be forced to pay out millions of pounds to passengers after the UK airline regulator started enforcement action against the budget carrier in response to an avalanche of complaints over unpaid refund claims. The Civil Aviation Authority (CAA) said it had been in contact with Wizz Air for several months after it received a high volume of complaints about the airline’s failure to pay passengers what they are owed, particularly in the wake of flight cancellations. Paul Smith, the regulator’s joint interim chief executive, said it had told Wizz Air that the way it had treated passengers over the past year was “unacceptable”. Smith said airlines “must meet their obligations to passengers when they cancel or delay a flight” and the regulator would “not hesitate to step in if we believe that airlines are not consistently doing this”. He said: “Passengers have every right to expect their complaints and claims to be resolved quickly and efficiently and to be treated fairly by airlines, in line with regulations. We will continue to watch the situation closely to check that passengers receive what they are owed and that Wizz Air’s policies have improved, so that consumers have a better experience if things go wrong.” The airline has engaged with the regulator and promise to introduce changes to its policies, procedures and passenger communications. It has agreed to reconsider claims it received for replacement flight costs, transfers when replacement flights were via different airports, and hotel costs. “This will make sure passengers who made claims to Wizz Air in the past but had their claims incorrectly rejected will receive the money they are legally owed,” the CAA said. The action by the regulator will cover claims made for flights due to depart from or arrive into a UK airport on or after 18 March 2022, and cases during this period will be automatically reviewed. Passengers can request for claims outside this period to be reopened as long as the flight was no more than six years ago. In 2022 the regulator took similar action against Ryanair to make the budget airline pay compensation to thousands of delayed passengers. Wizz Air, which earlier this year was named the UK’s worst airline by the consumer body Which?, is frequently criticised over its customer service. As well as being left stranded when flights are cancelled, passengers complain about being charged fees at the airport by the airline when they have been unable to check in due to technical problems with its website. At the end of last year, the CAA said it had “significant concerns” about Wizz Air’s “unacceptable” behaviour, as its passengers were far more likely to make escalated complaints than those of other carriers. The regulator also found that the airline was delaying paying money owed to passengers. At the time the CAA said Wizz Air had the highest number of complaints escalated to either alternative dispute resolution (ADR) schemes or its in-house complaints team. It also flagged the large number of unpaid county court judgments made against it (passengers can seek redress from an airline via a small claim). Wizz Air says it has now cleared the majority of these. Marion Geoffroy, the managing director at Wizz Air UK, said that during 2022, like other airlines, it had faced unprecedented operating challenges. “Flights were too often late or cancelled, disruption management overwhelmed our internal and external resources, and claims took too long to process and pay,” she said. “We have learned from this experience and have taken significant steps to make our operation more robust.” Rory Boland, the editor of Which? Travel, said Wizz Air had an “abysmal” record on meeting its legal obligations under consumer law, racking up millions in pounds in county court judgments after continually failing to appropriately reroute passengers from delayed or cancelled flights and then refusing to reimburse those passengers for its failure.