You check into a hotel expecting a $400 bill, then open your banking app and discover $550 or more temporarily tied up. That surprise is usually a hotel credit card hold, not an extra charge, and it can affect how much credit or cash you have available during your trip. Hotels use these authorizations because the amount you ultimately owe may not be known when you arrive.
Understanding where the practice came from—and what happens to your money—can prevent an unpleasant vacation-budget surprise.