Ryanair has apologised after a number of compensation cheques issued to passengers bounced.
The budget airline blamed an “administrative error” for cheques being sent out without a signature in July.
Consumer complaints service Resolver said it was aware a number of Ryanair passengers had encountered problems with unsigned cheques issued when flights had been delayed or cancelled.
The cheques were issued after the airline had to cancel flights due to striking Irish pilots in July.
Uo to 30 flights were cancelled, affecting 5,000 passengers.
Another strike in August by pilots in five European countries saw hundreds of flights cancelled.
Ryanair said the cheques had been re-issued to customers with a letter of explanation on August 15.
“We apologise again for any inconvenience caused to customers,” the airline told the BBC.
A number of passengers complained they had been delayed in receiving compensation because their cheques had failed to clear.
Another passenger wrote on Facebook on July 28:
“Ryanair sent me a cheque for compensation then BOUNCED the cheque..ended up costing me 32 eu (£29) for the privilege. SHAME ON YOU RYANAIR. won’t respond to EMAILS and OPERATOR just put the phone down on me”.
The airline told the BBC: “Ryanair complies fully with EU261 legislation, under which no compensation is payable to customers when the (strike) delay/cancellation is beyond the airline’s control.
“If these strikes, by a tiny minority of Ryanair pilots, were within Ryanair’s control, there would have been no strikes and no cancellations.”
Additional reporting by the Press Association.