How a card is charged

The credit card sale process works as follows: The vendor sends an authorization request for the value of the sale. The credit card company checks the card limit and reduces the credit limit by that amount (it puts a “hold” or a “block”) and sends the vendor electronic confirmation that the card is good. The vendor sends a deposit transaction or a sale transaction. The credit card company sends the money. This process is usually quick and painless…
# Hotels and rental car agencies usually send an authorization request for the estimated cost of your stay or rental and they keep this “block” on your card for 10 to 15 days (independent of how long you actually stay there) even if you pay with something else.
# When you use a credit card at a gas pump, the pump authorizes the purchase for something in the neighborhood of $50 first. So if you have less than $50 left on your limit, the pump will reject your purchase attempt.