As part of the enforcement action, Wizz Air will also be required to provide information to the UK Civil Aviation Authority about its review of closed expenses claims. The regulator will also review a sample of the claims that Wizz Air relooks at, so it is satisfied that passengers receive what they are owed. Paul Smith, Joint-Interim Chief Executive at the UK Civil Aviation Authority, said: 'This enforcement action sends a clear message that airlines must meet their obligations to passengers when they cancel or delay a flight. We will not hesitate to step in if we believe that airlines are not consistently doing this. '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 made it clear to Wizz Air last year that the way it was treating passengers was unacceptable.