Last Updated on January 28, 2024 by Elizabeth

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Running late? Want to tack on an extra day to your vacation? Need to keep your rental car for a few more hours or a few more days? In general, rental car companies will accommodate you as long as you go about it the right way.

Why You Need a Car Rental Extension

You might think that if you need your rental car for an extra hour or two, it’ll be no problem. After all, the rental car company has your credit card number. They can just charge you for the extra time, right? Unfortunately, it doesn’t work that way.

Returning a rental car late without clearing it with the rental company is a sure way to get stuck with a big fee.

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How late does a car have to be to start accruing fees? Most rental car companies offer a short grace period of 29 minutes from the return time. If you return the car after the grace period ends, the rental car company typically charges an hourly rate until the car is returned. This is usually one-third of the daily rate for the first hour, two-thirds of the daily rate for the second hour, and after 2 hours and 29 minutes, you’ll typically pay a full additional day.

Some companies will charge a per day late fee if you keep the vehicle longer but don’t notify them. For example, Avis and Budget will charge a $10 per day late fee if you don’t call or extend your rental online within seven hours of your originally scheduled return time, and Hertz will charge a fee of $12 per day late fee (up to $60) starting 12 hours after your scheduled return time, so you’ll want to plan accordingly.

How Extending Your Car Rental Can Affect Price

You need to know that changing your return time will almost certainly mean that you will be charged more. But how you handle it can mean the difference between a little more and a lot more.

First, if decide to you return your rental car late, the company will likely charge a Contract Modification Fee in the ballpark of a flat $10. But that’s less than the up-to-$20 per-day late fee you would get hit with if you didn’t notify them.  

Will your base rate change?

Also know that if you extend your car rental, it’s possible that your base rate will change. The price on your rental car is locked in for the time period you reserved. So if you reserve a vehicle for a five-day period, the rate is valid for that window only. If you change the return time, you might also change the base price.

Finally, if you are returning your rental car to an airport location, changing the return time can impact airport taxes. For example, if you extend a six-day weekly rental by one day, your base rate may not change. But you’ll need to pay an extra day’s worth of airport taxes.

How to Get a Car Rental Extension

Many of the major car rental companies are on the same page in terms of how they handle extension requests. The preferred way to get an extension is by phone or in person, and most direct you to contact the specific car rental location where you picked up the car.

Only Fox and Hertz currently offers an option to extend a car rental online. Several companies—including Avis, Hertz, and National—allow customers to extend an existing rental through a mobile app. So if you need an extension, you may have to pick up the phone.

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That said, different companies have slightly different policies if you are returning to an airport location versus a neighborhood location. And be aware that the rental car company may place an additional hold on your debit or credit card to cover any additional expected rental charges. Upon your return of the car, the holds will be released.

If you are extending a car rental by phone, tell the agent how much longer you’ll need the rental. They’ll be able to quote you the revised amount. Have your rental contract handy, since you’ll need the reservation number. If you don’t have that number, have the tag number from the car keys handy. Agents can sometimes look up your rental contract with that information.

Step-by-Step Guide to Extending Your Car Rental

Alamo: Call the Alamo location where you picked up your car and ask for an extension. The national customer service number is (800) 462-5266.

Avis: Call (888) 897-8448 and follow the prompts from the automated operator. Alternatively, you can extend your car rental on the Avis app.

Budget: Call (800) 824-6287 and follow the prompts from the automated operator.

Dollar: Call (866) 434-2226 and press 1 for English, then press 2 for a rental in progress, then press 1 to extend your rental. You can also extend your rental online by visiting

Enterprise: For airport locations, call (844) 515-1345. If you rented from a non-airport location, contact the renting location directly. The phone number for the location is at the top of your rental contract.

Fox: Extend online or call (855) 484-8624.

Hertz: Call (800) 654-4174. You can also extend your car rental online or extend your rental from the Hertz app.

National: Call (844) 393 9989. When prompted by the automated operator, say that you’re calling about a rental extension for a car you already have. You’ll be connected to a human. Alternatively, you can extend your car rental on the National app.

Payless: Call (800) 729-5377, then press option 1, then press option 2 to be connected to an agent.

Sixt: Call (888) 749-8227, then press 1 for English, then press 2 to extend your rental.

Thrifty: Call (877) 283-0898 and press 1 for English, then press 2 for a rental in progress, then press 1 to extend your rental. You can also extend your rental online by visiting

For all other companies, call the local branch or the customer service number on the rental contract to inquire about how to extend your rental.