Many holidaymakers affected by XL's collapse will be able to claim a full refund - but it depends on how they booked their trip.
Those who paid by credit card or used a tour operator affiliated to the Air Travel Organisers' Licensing (Atol) scheme should get their money back.
But people who used a debit card to book directly with XL Airways through the website XL.com or an XL call centre will probably not be protected.
Those who organised their holiday through XL-owned Medlife Hotels will also not be covered by the Atol scheme.
A terse statement posted on XL's website by the company's administrators warns that some Britons currently abroad on holiday could have to pay for their flights home.
The Atol-protected travel operators owned by XL trade under the names Cruise City, Excel Holidays, The Florida Skytrain, Transatlantic Vacations, Travel City Direct, Travel City International, Kosmar Holidays, Freedom Flights and Aspire Holidays.
People who booked with one of these companies should be able to stay in their hotel or villa and complete their holiday.
The Civil Aviation Authority (CAA) will arrange for them to be flown home.
But those who booked directly with XL Airways or through Medlife Hotels will have to pay again to get home, whether on one of the CAA's specially organised flights or by making their own arrangements.
They can make a claim for their expenses through the stricken company's administrators - but there is no guarantee this will be successful.
People who have yet to set out on their holidays are advised not to travel to airports.
They should contact their tour operator if they booked with an Atol-affiliated company.
But those who organised their break through XL Airways or Medlife Hotels are facing the prospect of losing their holidays - and possibly their money too.
XL's administrators added that passengers may be covered by their travel insurance, credit card or Visa debit card.