Why was I double-charged after paying in full when making the reservation? When I went to the car rental office in the US to pick up the car, I had to pay the full amount again. The car rental website charges the full amount automatically from the bank at the time of booking, not upon pick-up. The time in between should be enough for the rental website and its US partner company to communicate and process the payment as per their agreement. However, when I arrived at the office to pick up the car, I was charged again.