--- title: "Car rental agreement" description: "A car rental agreement is the contract behind every rental car. What it covers, what shows up as line items and what to check before you drive off the lot." canonical: https://engine.com/glossary/car-rental-agreement updated: 2026-11-02 author: "Engine Editorial" --- # Car rental agreement A car rental agreement is the contract between a renter and a rental car company that sets who may drive, when and where the car goes back, and what the renter owes for fuel, fees and damage. Also called: rental agreement Updated November 2, 2026 by Engine Editorial ## What is a car rental agreement? A car rental agreement is the contract you accept when you pick up a rental car. This cheat sheet covers how to think about one and what to check before you drive off. The detail is further down. ### How to think about it - **You agree by renting.** Taking the car means accepting the terms of the rental agreement. Hertz's UK agreement, for example, combines its terms and conditions with the details on the rental record. - **Only authorized drivers drive.** The car may be driven only by the renter or someone the company has authorized first. An unauthorized driver can void a damage waiver. - **Return time and place are terms.** The car goes back at the location, date and time in the agreement. Under Hertz's UK terms, each overdue day or part-day costs an extra day's rental. - **Extras show up as line items.** An optional damage waiver can appear as a separate line item on the rental agreement, and so can location fees. ### What to check before you drive off - **Fuel and mileage.** Verify that the fuel level and mileage match the rental agreement. Hertz's UK terms add a refueling charge when a car comes back with less than a full tank. - **Existing damage.** Photograph scratches, dents and equipment mounts with the rental agent present, so a damage charge weeks later has an answer. - **Mileage caps.** Some contracts cap mileage at 150 miles a day, which is only 750 miles over a five-day rental. - **Extra charges.** Enterprise lists possible mandatory charges such as a customer facility charge, airport concession fee and vehicle license recovery fee. ## How it works on Engine On Engine's [rental car booking](https://engine.com/features/rental-car-booking), you assign a driver, complete the required company fields and traveler details and review the payment options for that reservation. You can add an eligible rental loyalty number, which Engine passes to the rental supplier. Reservation terms, payment timing, pickup requirements and cancellation fees vary, so review the details shown for the selected rental before booking. ## Book the car, assign the driver On Engine, you can book a rental car, assign the driver and fill in your company's required fields in one flow. Free to use. [Get started](https://engine.com/sign-up) ## Questions ### Who can drive a rental car? The renter and anyone the rental company has authorized first. Drivers under 25 often face added fees or vehicle restrictions. ### What happens if I return a rental car late? It depends on the agreement. Under Hertz's UK terms, you are charged an extra day's rental at the daily rate for each day or part-day the car is overdue. ### What if the rental car is damaged? Hertz's UK terms ask renters to report accidents, theft or damage to the police right away where possible, and to Hertz within 24 hours. Under the same terms, the renter is responsible for any loss or damage to the car, and an optional Collision Damage Waiver reduces that. ### Can I change a rental car reservation booked on Engine? The documented workflow on Engine is to cancel the existing rental and create a new reservation. Cancellation costs and refund eligibility depend on the reservation terms. ## Go deeper - [Field crew car rental guide](https://engine.com/blog/car-rental-tips) - [Rental car booking on Engine](https://engine.com/features/rental-car-booking) - [Collision damage waiver](https://engine.com/glossary/collision-damage-waiver) - [One-way car rental](https://engine.com/glossary/one-way-car-rental) ## Sources 1. Hertz (U.K.) Limited, "Terms and Conditions of Rental," https://www.hertz.com/rentacar/reservation/reviewmodifycancel/templates/rentalAgreement.jsp, accessed November 2, 2026. 2. Enterprise Rent-A-Car, "Rental Rate Details," https://www.enterprise.com/en/business-car-rental/business-car-rental-terms.html, accessed November 2, 2026. 3. Wisconsin Department of Agriculture, Trade and Consumer Protection, "Car Rentals and Collision Damage Waivers," https://datcp.wi.gov/Pages/Publications/MV-CarRentalCollisionDamage260.aspx, accessed November 2, 2026. 4. Engine, "Field Crew Car Rental Guide: Save Money, Skip the Hassles," https://engine.com/blog/car-rental-tips, accessed November 2, 2026. 5. Engine, "Rental Car Mileage Fees: What You Need to Know For Crew Travel," https://engine.com/blog/rental-car-mileage-fees, accessed November 2, 2026. 6. Budget, "What is an Airport/Premium Location Surcharge?," https://faq.budget.co.uk/question-category/fees/, accessed November 2, 2026. 7. Engine, "Rental Car Booking for Business Travel," https://engine.com/features/rental-car-booking, accessed November 2, 2026.