Bath-based Groupia, which also offered golf and school trips, traded as Groupia Golf, GoHen, StagWeb, Groupia School Trips and Company Away Days.
It entered administration on 16 June, with Nigel Fox and Christopher Marsden of S&W Partners LLP appointed joint administrators.
Groupia was bonded with Abtot, which has confirmed the 16 June failure and will provide support with any claims.
"The company has now ceased taking new bookings, and arrangements are in place with Abtot to support customers with existing bookings," said Groupia.
Groupia was founded in 2002 and offered trips, including stag and hen dos, golf and spa breaks, and team events, to range of European destinations.
All bookings departing on or before 31 August 2026 will proceed as planned, said Groupia. All bookings departing on or after 1 September 2026 will be cancelled and subject to a refund claim.
For those booked to travel on or before 31 August, Groupia advised: "Abtot have arrangements in place and your event is expected to go ahead as planned. Please continue to use the company's existing VIP booking system to manage your booking."
Those booked to travel on or after 1 September are advised to make a claim, depending on how they paid.
Anyone who paid by credit or debit card have been advised to seek a refund from their card issuer; those who paid by other methods should submit an online claim to Gallagher Bassett, who are acting for Abtot.
Abtot said its aim was to complete all claim payments "as soon as possible" and confirmed it had employed additional resource to process them.
Abtot also confirmed several types of booking not protected by its bond, which will require customers to pursue via the administrators.
These include flights, day trips and activities without overnight accommodation, travel insurance costs, and gift vouchers and vouchers given as a goodwill gesture.