A travel company has gone bust after more than 50 years of trading, leaving customers scrambling to salvage their holidays.
Ickenham Travel Group stopped operating in November, according to the Civil Aviation Authority.
Peter Reglar established the business in 1970. Over the decades it expanded to include Abu Dhabi Holidays, Ras Al Khaimah Holidays and Letsgo2.
Holidaymakers who were abroad on November 20 have been told to get in touch with the airline listed on their tickets.
Anyone due to fly since that date faces uncertainty over whether their package remains valid. It depends on the booking terms and ATOL protection status.
The CAA said: "If the airline confirms you have a valid ticket for travel, you may have the option to travel.
"However, other services may not have been paid to the local suppliers, and you will be required to re-arrange and pay for these services again."
Affected passengers face a choice between two routes forward.
They can board their flight as planned, then reclaim costs for replacement hotel rooms, transfers and other services they're forced to book again.
Any substitute arrangements must be of comparable quality to what was originally reserved, according to ATOL rules.
But travellers taking this approach lose the safety net their original package provided. If something goes wrong, they're on their own.
The regulator warned: "You will therefore be responsible for any risks arising from each individual element of your trip which would have previously been protected."
The other option is scrapping the trip entirely and claiming back the full cost.
Anyone whose holiday was scrapped before the firm entered administration can apply for compensation through ATOL.
LetsGo2 began life as a chain of high street shops with locations in Harrow, Hillingdon, Rickmansworth and Northwood. It shifted to online-only operations in 2005.
The failure adds to mounting casualties in the struggling travel sector.
Great Little Escapes shut down earlier this year, ATOL confirmed.
That followed the demise of Balkan Holidays, a Bulgaria specialist that once flew customers from more UK airports than any rival. Passenger numbers had plummeted from a high of 130,000.
