Booking into a hotel?

Question

Does it matter how old you are when you book into a hotel or is it 18+

Answer 1

It depends on what country you are in. Many hotels in the US won't let you get a room unless you are 21. They have had to much room damage and people dodging bills with the younger crowd. They just plain don't want the younger business. They can be nasty about it as well.
Most places over seas don't care so much about age. If you have your passport you can get a room. They hold your passport so they know that you can't leave without paying or after trashing the room. Money talks in most places.