Airlines stand accused of using “rip-off” no-show clauses to cash in when a passenger misses the first leg of a return flight.

Cases of passengers left stranded and hundreds of pounds out of pocket by carriers exploiting the little-known clauses that are often buried deep in the terms and conditions, are highlighted by consumer group Which?

All their connecting or return flights are then cancelled, typically with no refund given.

In some cases airlines are effectively able to double their money by reselling the seats they cancel, with no refund given to passengers.

Which? is urging the Civil Aviation Authority to put an end to the practice by enforcing an outright ban on the clauses.

The consumer champion wrote to nine airlines in December, including British Airways and Virgin Atlantic, informing them that the practice is potentially in breach of both the Consumer Rights Act and the Unfair Terms in Consumer Contracts Directive.

This is because the clause creates a “significant imbalance” between the airline, which stands to profit from the term, and passengers who face having to pay out considerable sums of money to rebook.

Flybe was the only carrier that pledged to make some changes in response, but it has not removed its no-show clause completely.

Which? had already secured commitments from Thomas Cook Airlines and Aurigny to scrap the terms, which have recently been ruled unlawful in Austria, before it wrote to the other airlines.

In one case reported to Which?, a theatre director and her child were stuck in Malaysia and had to hand over £600 to Malaysia Airlines to return to the UK, leaving the young mother suffering from anxiety around flights and travelling.

In another, a musician from Bristol had to buy a new return flight from Portland in the US to Heathrow for nearly £700 with Virgin Atlantic after work commitments meant that she was unable to take her scheduled outbound flight.

The consumer champion also heard from a holidaymaker who has vowed never to fly with BA again after having to pay more than £600 to get home when the airline cancelled return tickets from Pisa for him and his wife.

The CAA concluded in a report released last week that a policy of automatically cancelling a passenger’s return if they do not take the outbound flight is “disproportionate”.

It also said that no-show clauses used by some airlines fell short of its expectations on “fairness and transparency” for consumers.

But Which? complained that the regulator stopped short of taking any enforcement action to prevent passengers from getting ripped off by the practice.

Which? advocacy director Caroline Normand said:“It’s totally unreasonable for an airline to cancel a passenger’s return flight – often without warning – simply because they’ve missed the first leg of their journey.

“Airlines have been able to cash in with this tactic for too long – leaving people miserable, stranded and hundreds if not thousands of pounds out of pocket.

“If airlines are not going to do the right thing and stop this disgraceful practice on their own, the Civil Aviation Authority should step in and ban these rip-off clauses.”

BA said: “Many of our tickets allow customers to make changes to their flights if they inform us before they travel.

“We believe that being upfront with customers is essential, so we work hard to give them the information they need when travelling with us, and ensure that our terms and conditions are very clear on our website, ba.com.

“This policy is common practice in the industry and designed to stop the abuse of our fares.”

Virgin Atlantic said: “Having worked with the CAA and listened to our customers we have now updated our policy on no-shows.

“We always encourage customers to get in touch as soon as they think they are going to miss their flight. If they arrive too late at the airport we will rebook them on the next available flight and their inbound flight won’t be cancelled.

“If a customer can’t make their flight due to a legitimate change in circumstances we will not cancel their inbound flight if they get in touch with us before the flight. If the customer can’t contact us before they miss their flight they will need to contact us as soon as they can and if there has been a legitimate change in circumstances we will reinstate their inbound ticket.

“As soon as customers know that they may miss their flight, we would always urge them to get in touch with us or their travel agent, so they can make alternative arrangements as quickly as possible.

“We would also like to emphasise that if customers are unable to take their outbound flight due to an event beyond their control, we will honour any onward or return journeys if we are provided with proof of such an event.”

Malaysia Airlines said: “As with most airlines, Malaysia Airlines has its own policies, which in our case is guided by Iata’s “General Conditions of Carriage” Article 6 and 7 regulations whereby the airline reserves the right to refuse travel for passengers who fail to check-in or board their confirmed aircraft sufficiently in advance of their flight departure.

“The carrier may cancel the space reserved; including that of onward or return travel; without liability for passenger loss or expense, and will not delay the flight.

“In addition, the airline’s no-show policy automatically cancels an onward booking when a passenger fails to reconfirm their intent to travel onto onward segments.

“For commercial reasons, if a passenger does not board one sector of their journey, the airline assumes that the passenger will not be travelling onto onward segments of their itinerary, unless the passenger informs the airline otherwise.”

tw3