Originally Posted by choptliva
Hotels frequently place a "block" of a certain amount (usually one night plus taxes) on your credit card's limit, just so it (the blocked amount) won't get used and they can be sure to recover at least the one night's revenues if you don't show. You are not being charged for it in advance. I wouldn't worry about it.
A "block" is not a charge but it does eat up your credit line. I found out the hard way when a rental car company put a "block" on a major chunk of the minimal remaining credit line on the card I gave them (which was more than sufficient to cover the car, hotel and incidentals on this trip). Very embarassing when a waiter came back to the table and asked if I had another card (I didn't).
Scrounged enough cash to cover the bill and leave a disappointing tip.