Peru is another country that does not charge taxes if your a foreigner. The hotel takes a bunch of photocopy of your passport along with the immigration card and also the page where your entry stamp was placed during checkin. I guess if you don't want to show your passport, you can pay the tax which is substantial. During my stay in Miraflores, the tax and no tax difference was about $100US! Back in SPG days, when you booked your room, it showed the price with the local tax but it was not charged at the hotel. It was a nice little surprise at the end to see such big drop in price.