The Scenic Group has suspended all its operations, including ocean and river cruises and land tours, until August 31.
Scenic Eclipse sailings will be suspended until September 30.
Colin Downing, managing director, UK said: "Our top priority is to ensure that our guests and employees are able to travel safely before we resume operations.
"Although we have seen some easing of national lockdowns, the restrictions on travel still vary considerably from country to country and it is sadly impossible for us to operate our scheduled departures up to 31 August 2020."
Booked guests are being offered a flexible ‘Future Travel Credit’ valued at 110% of any money paid for cancelled river and cruise booking and 100% of any money paid for affected land tours.
Future Travel Credit can be applied to any new or existing booking across the portfolio of brands up to the end of June 2023 and it can be transferred to another gues.
Should a guest be unable to travel by June 30 2023, they will be given a refund.
The Scenic Group said it will protect agent commissions on bookings for cancelled cruises that have been paid in full and for the total amount of the Future Travel Credits.