What voids a car warranty?

Keep up with maintenance and avoid aftermarket modifications to get the most from your coverage

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Your car's warranty, whether it's from the original manufacturer or a third-party vehicle service contract company, is a contract between you and the provider. You must take care of routine maintenance to keep your car in good condition and prevent future mechanical problems, and the company providing warranty coverage promises to take care of any repairs due to the failure of one of the car's covered parts or systems.

If you don't stick to the manufacturer's recommended maintenance schedule, you may have your warranty claims denied. Voiding a warranty means that even though you paid for an extended auto warranty or your car is still covered by the original manufacturer's warranty, your unwillingness to adhere to a preventive maintenance schedule or follow the rules about aftermarket changes to your vehicle frees the warranty provider from the contract.

What could void your warranty?

There are several actions that can void an auto warranty, so be sure to take care of your car and and avoid the following:

Salvage title

If your car was in an accident and the cost to repair the damage is high enough that your state requires a salvage title or your insurance company deems your vehicle a total loss, your warranty is voided.

When shopping for a used car, it's important to avoid vehicles with a salvage title if you know you’ll want an extended auto warranty to help pay for future repairs.

Follow the manufacturer's maintenance schedule to avoid warranty issues.

Vehicle misuse

Off-roading, racing or competing with your car — generally, any actions outside of normal day-to-day use — could be interpreted as misuse. If your car shows signs of abuse from such activities, your warranty provider could void your coverage entirely.

Even if your car or truck was designed for off-roading (or if advertisements feature the vehicle in off-road conditions), the terms of your warranty may exclude repairs due to "excessive wear," so read your coverage details carefully before you leave well-traveled roads in pursuit of off-road adventures.


Failing to take your car in for routine maintenance is a sure way to void your warranty. Make sure to adhere to the maintenance schedule created by the manufacturer and published in your owner's manual.

Aftermarket modifications

Though putting aftermarket parts on your car or modifying it may not automatically void your warranty, it could complicate matters when you need coverage for a repair. According to the Magnuson-Moss Warranty Act of 1975, a dealer must provide proof that the aftermarket part or system caused the need for repairs before it can deny a warranty claim.

How to get the most out of your car warranty

Here are some tips on how to get the most value out of your vehicle warranty:

  • Read your warranty documents or third-party warranty provider plan. Pay special attention to the "What is not covered" section to make sure you understand exactly which repairs you'll pay for on your own.
  • Service your car and document everything. If you have your car serviced at a dealership, it may recommend fluid changes and other maintenance in accordance with the manufacturer's schedule. Many people have an independent repair shop they like, which may not be tapped into a specific manufacturer's recommended maintenance schedule.

    Take the recommended maintenance schedule seriously and keep receipts and other forms of documentation for each service appointment.

  • Remember that warranties are often open to interpretation. If your claim is denied, don't panic. Ask questions and go through the warranty company or manufacturer's process to appeal a decision. A service advisor may have made a simple clerical error, or a customer service representative may have unfairly denied your eligible claim.
  • Set up a separate auto maintenance fund. One of the simplest and most justifiable reasons for a denied claim is improper maintenance. If you’re on a budget, plan for regular maintenance by building the costs into your plan. If you set aside a bit of each paycheck in a separate account, when it's time to pay for an oil change, timing belt replacement or new tires, you won't be tempted to put it off due to a lack of funds.

Quick and easy. Get matched with an Auto Warranty partner.

    What if your claim is denied?

    If your warranty isn't honored, talk with the mechanic or service advisor to make sure the repair was properly labeled and the reason for the repair was explained in the paperwork you submitted to the warranty company.

    Call the customer advocacy number in your car's manual if your claim was denied by the manufacturer. If you have a third-party warranty, resubmit the claim with a letter detailing why you believe your claim is valid. Include paperwork that proves you've kept up with the manufacturer's routine maintenance schedule.

    Call the customer advocacy number in your car's manual if your claim was denied by the manufacturer.

    If you suspect you've purchased a useless warranty or if you think you’re working with a company that routinely denies claims, look into canceling your coverage and getting a prorated refund.


    Does missing an oil change or changing your own oil void a warranty?
    Maybe. If you missed a single oil change or were late changing the oil, the warranty may not be void, but it could lead to denied claims. To be safe, pay attention to your car's mileage and when you get close to the date or number of miles for a recommended oil change and make an appointment to have the work done on time.
    Can aftermarket exhaust void my warranty?
    It can. If you have a third-party extended auto warranty, check the listed reasons for a voided warranty included in the contract. If your car is covered by an original manufacturer's warranty and your aftermarket exhaust caused problems in need of repair, the manufacturer might deny your claim.
    Can I take my car to a different dealership for warranty service?
    In general, you can choose any of your manufacturer’s dealerships as long as it has a service department equipped to handle warranty claims. If you have a third-party warranty provider, check for restrictions regarding where you can go for service.
    What should I do if my warranty isn’t honored?
    If the car's manufacturer or a third-party warranty company isn't honoring your warranty, find out why. Ask for the reasons in writing and talk with your dealership's service manager or a warranty company representative to try to resolve the situation. You may have a low-quality aftermarket policy, or there may be a misunderstanding with a customer service provider. Remain calm and be polite, but persist until you understand exactly why you aren't getting the coverage you thought you had on your car.

    Bottom line

    If you’re fortunate enough to have a manufacturer's warranty or good third-party auto warranty, it can help you avoid the financial stress associated with high car repair bills. For you to get the most out of your warranty, it's crucial to understand your coverage limits, how to make a claim and what actions void your warranty. Read your warranty details to get insight into what to do and what not to do to get the maximum value from your warranty.

    ConsumerAffairs writers primarily rely on government data, industry experts and original research from other reputable publications to inform their work. To learn more about the content on our site, visit our FAQ page.
    1. Federal Trade Commission, “Magnuson Moss Warranty-Federal Trade Commission Improvements Act.” Accessed Dec. 16, 2021.
    2. Edmunds, "What Voids Your Vehicle's Warranty?" Accessed Dec. 16, 2021.
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