If you have already picked up your rental truck and wish to extend the reservation, you must contact the company where you picked up the truck. If you have not picked up the vehicle, you can contact the Montreal rental company to modify or cancel your reservation. However, if you happen to alter your rental pickup truck’s drop-off or pick-up location, time, or date, your rates, taxes, or extra charges may be affected. Make sure to read all the fine print when verifying your reservation. Also, if you booked a reservation via a third-party website like KAYAK, you will need it for any modification of the pickup truck rental. Search rental cars on KAYAK