The holiday firms Late Rooms and York-based Super Break have collapsed, affecting more than 50,000 travellers.
Malvern Group, which owns the booking website LateRooms.com and Super Break, said about 400 Super Break customers were on holiday in the UK or overseas.
The travel trade body ABTA said Super Break was a member and that most customers affected should be able to get a refund for their trip. It added that those already away should be able to continue with their holiday as normal.
The two companies had about 53,000 customers between them, involving 20,000 bookings, with most holidaymakers yet to start their trips.
“The majority of customers are yet to travel and in most cases they should be able to obtain a refund, either through ABTA or another financial protection scheme, depending on the type of booking,” ABTA said. “The vast majority of holidaymakers’ arrangements will be covered.”
However, Malvern Group, which has shut its contact centres for the two businesses, said Super Break holidaymakers who had bought gift vouchers would not be able to use them.
Late Rooms, which is not an ABTA member, said it did not take payments directly from customers and that it anticipated bookings with accommodation suppliers were secure.
“LateRooms.com acted as an agent on behalf of your accommodation supplier, therefore we anticipate that your reservation is secure,” the company said in a statement to customers. “We recommend, however, that you contact your accommodation supplier directly prior to travelling to confirm.”
LateRooms continued to drum up business only hours before the company ceased trading. Late on Wednesday, LateRooms tweeted that it was “never too late for a cheeky weekend up in Manchester”.
The parent company, Malvern Group, which employs about 250 staff, said it had appointed KPMG as administrators.