Ryanair has agreed to make sure all passengers affected by flight cancellations are “fully aware” of their rights and entitlements.
The company says it has met with Ireland’s aviation regulator and is now issuing a “clarification email” to thousands of affected customers.
The email will outline people’s right to a refund, explain how they can be booked on to another flight and whether they can claim expenses.
But Ryanair has hit out at the UK’s Civil Aviation Authority, complaining that British Airways was not held accountable in the same way when an IT meltdown stranded 75,000 passengers in May.
If an airline cancels a journey it must offer passengers an alternative flight under European Union law, according to CAA guidelines.
Customers “may have the right” to be booked on to flights by an alternative airline if it would mean reaching their destination “significantly sooner”.
If it cannot offer a flight on the same or the next day from the original airport or a “suitable alternative”, Ryanair says it will book passengers on to services operated by easyJet, Jet2, Vueling, CityJet, Aer Lingus, Norwegian or Eurowings.
Should these options not be possible, it will offer “comparable alternative transport” which may be a flight, train, bus or car hire, with costs “assessed on a case-by-case basis”.
Ryanair said its statement met the requirement of the CAA to clarify the airline’s obligations according to EU261 rules.
Kenny Jacobs, Ryanair’s chief marketing officer, said: “We apologise again sincerely for the disruption and inconvenience our rostering failure has caused some of our customers.
“We have taken on extra customer service staff and are moving now to process and expedite all EU261 claims from affected customers.
“We are committed to processing all such claims within 21 days of receipt and hope to have all such claims settled before the end of October.”
Andrew Haines, CAA chief executive said: “Our job is to protect passengers’ rights and ensure that all airlines operating in the UK are fully compliant with important consumer laws.
“Where we find that an airline is systematically flouting these rules, we will not hesitate to take action, to minimise the harm and detriment caused to passengers, as we have done with Ryanair in recent days. It appears that Ryanair has now capitulated.
“We will review their position in detail and monitor this situation to ensure that passengers get what they are entitled to in practice.”
Mr Haines added that the CAA has been “consistent” in its approach – securing 22 legal undertakings from airlines and travel companies on a range of issues to protect consumers.
The CAA intervened after the airline cancelled another 18,000 fights for the winter season on Wednesday, affecting 400,000 customers.
The new cancellations include several popular routes used by UK passengers, such as Stansted to Edinburgh and Glasgow, Gatwick to Belfast, Newcastle to Faro, and Glasgow to Las Palmas.
It fuelled further fury with Ryanair, which was already coming under heavy criticism after scrapping up to 50 flights a day earlier this month.
Passengers have been furious with the carrier after being left out of pocket because of a lack of alternative flights and accommodation bookings they can no longer use.
The carrier said the cancellations were due to an error with pilot holiday rosters.