Someone wanting to cancel last minute because of corona virus

They wish to cancel a booking for this Monday I don’t know if they have corona virus or not I have told them they can cancel with a £100 cancellation fee as I think I will need to still pay booking.com there commission 

Isle of Wight … 1 year ago

Coronavirus is a known risk - they should have travel insurance to cover them for illness, which includes coronavirus.

But of course, if you don't refund them, you do have the risk that they'll post a negative review .....