Thomas Cook collapsed on Monday after it failed to secure $250 million in rescue funding, stranding thousands of holidaymakers around the globe.
In a statement, the British travel operator said its board "concluded that it had no choice but to take steps to enter into compulsory liquidation with immediate effect".
The UK government said it had hired planes to fly home an estimated 150,000 holidaymakers to the UK, in an operation starting on Monday.
"All customers currently abroad with Thomas Cook who are booked to return to the UK over the next two weeks will be brought home as close as possible to their booked return date," a separate statement said, describing it as the largest repatriation in peacetime history.
The firm ran hotels, resorts and airlines for 19 million people a year in 16 countries.

Nakheel unveils new sustainable community beside Palm Jebel Ali
Dubai showcases latest innovations in electric, smart mobility
US sues Lyft, alleges discrimination against disabled riders
ADNOC Distribution reports $791 million net profit in first 9 months
Tesla to pull the plug on Cybertruck after years of poor sales
