I find this interesting. I booked my rental at Zurich last November and unbeknownst to me using my debit card (saved on file). When I went to pick up my vehicle, I gave the representative a credit card, but told me they did not need it as I had a card on file. They never swiped it. I don't know what happened, but I got away with renting a car in Europe using only my debit card with no hold on it.