Examine your rental agreement. Find the extra-day price to see how much it will cost you for the first extra day. If you plan to return the car only one day late, this is the only cost you will incur and you don't need to call Hertz.
Dial the Hertz rental extension line at 800-654-4174 to extend your rental agreement for more than one day. The line is staffed 24 hours a day.
Give the Hertz agent the confirmation number on your rental agreement.
Tell the agent how many additional days you'd like to keep the car.
Stay on the line until the agent tells you that your new rental agreement has been confirmed.
