Upvote:2
Some hotels do, some don't. I dont think anyone has statistics on if this is most or not. Hotels charge per room, per guest or a base rate for n-guests plus fee for additional guests. All these are common options and, depending where you travel, you might see more of one type or other. There are also a number of other rules such as children under Y age stay free with paying parents.
While this makes a lot of options, once booked for the correct number of guests, this should not be a surprise. The booking should have the full price, sometimes excluding local taxes and tourism fees, for the room given the number of people requested. Many online booking sites also specify which fees are excluded below the price on the booking confirmation.
Upvote:3
Most hotels charge different rates for the same room depending on how many gusts will be using it.
But this should not be a surprise. If you book the room through somewhere like hotels.com and enter "1 room, 4 occupants", it ought to show you the hotel's rates for that occupancy, not something else that a surcharge will later be added to.
If you have already booked a room, but made the booking for fewer people than you will actually be, you should contact the hotel now and ask about changing your booking to be for more occupants. This may involve an increase in rates, of course.