Huddersfield-based Air Parade, which traded as Luxury Villa Escapes and Villa Parade, ceased trading yesterday. It mainly sold packages to Spain and Portugal.
The Association of British Travel Agents (Abta) estimates the firm has up to 70 customers currently abroad, but their holidays should go ahead as normal.
Abta said the firm has around 1300 bookings for future holidays with villa accommodation only. These will be cancelled, although customers will get their money back via Abta's financial protection scheme.
Around 400 bookings for flight packages will also be cancelled, with refunds paid via the Air Travel Organisers' Licence scheme.
Villa Parade's website has been replaced with a page telling customers to contact Abta, or the Civil Aviation Authority if their booking involves a flight.
The firm has been locked in a legal battle with holiday rentals firm Travelopo.
Details emerged after some Villa Parade customers received emails from Travelopo telling them their villa bookings were not valid.
Last month, the firm stated that the majority of bookings were "secure and will be fulfilled".