The now-defunct Holidays 4 UK

British tour operator Holidays 4 UK Limited, which also traded as Aegean Flights, has gone under, leaving 12,000 travelers stranded abroad and up to 50,000 ticket holders without a vacation after running into financial difficulties due to the downturn in the travel industry in the past few years.

The company was established in 1994 and described itself as an "independent specialist in providing cheap Turkish holidays." The tour company specialized in package deals and flights to Turkey, but can now no longer help the thousands of customers who have booked with them.

Customers of Holidays 4 UK are protected under the Civil Aviation Authority's (CAA) Air Travel Organisers' Licensing (ATOL) protection system, which means those currently abroad on vacation will be able to complete their trips and return the UK, mostly on time.

The Istanbul-based airline Onur Air, used by Holidays 4 UK, has indicated it will fly passengers home. They advised travelers to arrive at the airport as planned to catch their flight home- though the CAA warned that they may not be able to return all passengers to their original airports.

Those who have booked a future trip are not so lucky. Starting immediately, all bookings have been canceled. The CAA warns ticket holders to not go to the airport as their tickets will no longer be valid, but rather to contact CAA (0844 4933 037; ) to start the process of refunding their trips.

The sudden announcement during the height of the summer booking season has left many travelers in a lurch to scramble for refunds and alternative travel plans. Sadly, this is not the first travel agency to succumb to the harsh economy and dwindling vacation funds- and it may not be the last.

If you are currently in Turkey and have booked with Holidays 4 UK, call the CAA at 0044 (0)161 444 5810.