Hey, life is unpredictable – not that knowing that is any comfort when your flight home is canceled or your business trip is extended. Of course, not all unexpected plan changes are bad; maybe your vacation is proving so wonderful that you simply can't bear to go home yet. Whatever the reason for your change in plans, you're going to need to keep your rental car longer than you anticipated. Rental companies are generally happy to accommodate that request if you make it in the right way.

Why Bother Getting an Extension?

If the event that triggered your change in rental car plans derailed other travel plans too, calling the rental company might not be at the top of your to-do list. You've got the car, and they've got your credit-card number; they'll just charge you for the extra day or two, right?

Right – but they'll add late fees too. It's customary for companies to charge $10 to $20 per day on top of other rental fees when a customer doesn't call to get an extension. It's important to be aware of late fees on the day that you eventually return the car, too. Rental car companies generally give passengers a very short grace period, usually 29 minutes from the return time on the customer's rental contract.

If a car is returned even one minute past that grace period, usually the company will charge the customer an hourly rate until it's returned. And if the car still isn't returned by the end of the late window (anywhere from two to seven hours after the initial return time, depending on the company), the renter is charged the full amount for an entire additional day. So when you do get your new return time established, be careful to stick to it.

How to Extend the Return Date

The major car rental companies are pretty consistent across the board in terms of how they handle extension requests. The main thing to know is that customer service reps will almost always say that extending the return date is no problem – it's more money for the company, after all – but the only way to get an extension is by phone or in person. No major companies currently offer an option to extend a return date online.

That said, different companies have slightly different policies. For example, getting a ‌Budget car rental extension‌ might be easier than getting one from Enterprise. ‌Budget car rental customer service‌ asks customers to speak to a representative at 800-824-6287 to change a return date. In contrast, customers only have to call ‌Enterprise to extend a rental‌ (844-377-0169) if they rented from an airport branch. Customers who rented their cars at non-airport branches have to go to the renting branch in person.

Keep These Things in Mind

Making a change to your return date is usually a free service, but company policy varies on this. Dollar car rental charges a $10 flat fee to make any changes, in addition to any other fees.

Before you finalize your plans to extend your rental, make sure you understand exactly what you'll be charged for. That may take a quick reading of the fine print on your contract. If you return your car a few minutes late, but within that 29-minute grace period, you might not be hit with a late charge, but you may be billed for an extra day's worth of fees and surcharges.

Also keep in mind that the daily rate you locked in for your original rental period may not be the same rate you're charged for extra days. If you got a low price for a midweek rental and want to keep it through Sunday, expect to pay more for those weekend days than you do for the weekdays.