Remember the last time you made a hotel reservation? Do you remember when they asked for your credit card number? There is a reason for that. Unless you cancel your reservation, you will be paying for that room, even if you don't show up.
Different hotels have different policies concerning cancellation. But you should always assume that you need to cancel your reservation the day before. The hotel I work in is fairly nice, in that they only charge "no shows" on nights when they are sold out. Some hotels however always charge no shows.
Tonight I charged various accounts and credit cards over $1300, for rooms where the people never showed up. Most of this was to various corporate accounts. Boeing alone pays our hotel about $4000 a month for rooms they reserve and then never show up for. That doesn't bother me very much. What bothers me is the people who make reservations for a vacation, and then don't show up.
Mr. Walsh made his reservation 2 weeks ago (I remember because I took the call). He was taking his family to Michigan and would be staying in our hotel for one night. (Why anybody would go to Michigan on a vacation I will never know.) He reserved 3 rooms for his family of 6 (at $129 plus tax, per room). However, Mr. Walsh and family never showed up. I had to charge $440.17 to this man's credit card for the rooms he didn't bother to cancel. I know what happened: the Walsh family decided that our hotel was too expensive, so they probably stayed at a cheaper one. The kids are going to be heartbroken when they get to scenic Detroit and find out that they can't afford to do anything, because daddy's credit card is maxed out, since he had to pay for the hotel they never stayed in.
Don't let this happen to you. If you are not going to the hotel, remember to cancel your reservation.