The departures to Switzerland have been suspended due to new rules on arrival.
The UK was put on a red list by Switzerland, meaning that visitors must stay for 10 days.
The ski operator said that customers could now move their booking free of charge or cancel their booking and get a full refund.
Those transiting to ski resorts in other destinations such as France are not affected by the situation.
Customers travelling through Switzerland for less than 24 hours can travel to another country without being required to stay in Switzerland.
Ski holidays in Switzerland account for around 6% of Ingham's winter programme and the operator said bookings had to-date been strong for the ski season.
The operator said that they were disappointed for their customers who were looking forward to a ski holiday in Switzerland.
The operator is allowing ski holidaymakers to change their ski break to a later date or different destination.
Many of our customers remain eager to return to the slopes, but we understand that some customers with later departure dates may be feeling a bit uneasy about their holiday.
We offer flexibility via our 'No Fee to change up to 28 days before departure' policy.
