More than 1,000 British tourists were facing a difficult journey home from Spain after travel company Sun4u collapsed on Friday, reports AFP.
The firm is believed to have been a victim of the Icelandic volcanic ash cloud crisis which shut down British airspace earlier this year.
British travel organisation ABTA said most Sun4u customers should be able to continue with their holidays as planned.
But it warned people who simply booked flights through Sun4u might have trouble getting back from Spain.
A spokesperson said: “There are approximately 1,200 people away at the moment and most of them are in Spain.
“Anyone who has booked a package holiday must contact the Civil Aviation Authority (CAA) or contact the supplier named on their invoice.”
The collapse of Sun4U follows the recent failure of tour operator Goldtrail Holidays, affecting 16,000 customers on holidays to Greece and Turkey.