Flight operations at Austrian carrier Niki have been suspended, leaving thousands of passengers stranded.
Passengers who booked their flight through a tour operator should contact them directly, the carrier said, as the they are responsible for getting them home.
Niki filed for insolvency protection earlier, grounding its near two dozen aircraft.
It had offered leisure flights to resorts in southern Europe and north Africa.
Niki advised passenger who booked their flight directly that several airlines have organised repatriation flights from overseas to Germany, Austria and Switzerland.
These are expected to take place until December 31st.
Condor, Eurowings, Germania, Lufthansa, Austrian Airlines, Swiss, and TUIfly are all involved in the efforts to get passengers home.
Around 5,000 passengers are believed to need assistance following the collapse, with many in Majorca.
Austrian authorities are trying to get them transferred to other flights.
Lufthansa has earlier scrapped plans to buy Niki after the European Commission expressed “deep competition concerns” about the possible deal.
The German giant was in discussions to purchase 81 planes from the failed airberlin and former subsidiary Niki.
However, the commission suggested the deal could limit choice for air travellers in Germany, Austria and Switzerland.
Niki - founded by former F1 driver Niki Laudar - was planning to operate at least 145 flights per week during the winter holiday season, from Austria, Switzerland and Germany.