Turkey specialist Mert Selim, based in North London, has ceased trading.
The company, which traded as Gezinet London and Parade Travel, was ATOL protected.
Customers had earlier been posting on TripAdvisor of deals that were ‘too good to be true’ and voicing concern that they hadn’t received tickets for their holidays.
The company sold luxury all-inclusive holidays, culture tours and city breaks to Turkey.
All future holidays booked with the company have now been cancelled but customers will be able to claim a full refund for their trip.
There are not believed to be any customers currently overseas.
Andy Cohen, head of ATOL at the CAA, said: "We understand this will be concerning news for anyone who has booked to travel with the company. However, the ATOL scheme exists for exactly this kind of situation and we are making immediate arrangements so all ATOL protected customers can claim full refunds as quickly as possible.
"So while this situation is very disappointing for the customers affected, it is also a timely reminder of the importance of remembering to check for ATOL protection when booking holidays."
