Participation in international trade fairs requires hotel accommodation for staff for the duration of the fair and is often organised and paid for well in advance. Recently, due to the health risks associated with the new corona virus, there has been an increasing number of postponements or cancellations of events by the various trade fair organisers in Germany, which causes quite a few difficulties for the participating companies. One of these is the question of hotel costs, which many hotels refuse to reimburse on the grounds of their cancellation policy, withholding part of the full charge as a cancellation fee, otherwise a percentage of between 90% and 60% depending on the service booked (with/without breakfast/half board etc.). However, the normal cancellation conditions of the individual hotel are not applicable if participation in the fair can be regarded as the basis for the accommodation contract, especially if it turns out that the fair was the decisive reason for the booked service for both parties. In such cases, the BGB provides for a right to amend the contract or, if a rebooking is impossible or unreasonable, a right of withdrawal in favour of the host company, which may therefore demand that the Hotel reschedule the reservation to another date or refund the full amount paid.