[I searched and found this thread, which FLYGVA was maybe a bit prompt in closing ]

Berlin has a new (since January) city tax of 5% payable on non-business hotel stays. Does anyone know if this is charged for award stays (ie where 'price' is zero)? fwiw, it's for a stay at the Grand Hyatt.

I did post in the Hyatt forum but no-one there seems to know. I hope that the cross-post is permissible in this instance...