An anti-theft device is a vehicle security system that deters car theft or helps recover a stolen vehicle. Insurers recognize three anti-theft device groups: passive systems, active devices, and tracking systems. Vehicle theft creates three financial risks for drivers: an uninsured vehicle loss, lost personal belongings, and the deductible. According to the NICB, thieves stole 850,708 vehicles across the U.S. in 2024. Only comprehensive coverage pays to replace a stolen vehicle. Insurers take 5% to 30% off the comprehensive premium when the vehicle carries a qualifying device. Insurance Navy helps drivers find the right insurance at the right price. This guide explains anti-theft device types, discount eligibility, savings amounts, discount duration, and participating insurers.
Table of contents
- Does Car Insurance Cover Theft?
- What Are The Best Types of Car Anti-Theft Devices?
- Passive Anti-Theft Systems
- Smart Keys and Relay Attacks
- Active Anti-Theft Systems
- GPS Tracking Systems
- Remote Disabling Systems
- VIN Etching
- Audible Vehicle Alarm Anti-Theft Systems
- How to Tell If Your Car Already Has an Anti-Theft Device
- How to Get an Anti-Theft Device Discount on Car Insurance
- What Qualifies as an Anti-Theft Device for a Car Insurance Company?
- How Much Can Anti-Theft Devices Save on Auto Insurance Rates?
- How Long Does an Anti-Theft Discount Last?
- Which Insurers Offer Anti-Theft Discounts?
- Do Factory Installed Car Alarms Qualify for Anti-Theft Insurance Discount?
- Frequently Asked Questions
- Will anti-theft devices raise your insurance rates?
- What is the best anti-theft tracking device for car insurance discounts?
- How much does a GPS tracker reduce your insurance premiums?
- Is it worth putting GPS trackers in my cars?
An anti-theft device in car insurance is a factory-installed or aftermarket system that deters vehicle theft or helps recover a stolen vehicle, such as an alarm, an engine immobilizer, a steering wheel lock, or a GPS tracker. Insurers treat an anti-theft device as a risk reducer. Insurers take a percentage off the comprehensive portion of the premium when a qualifying device is installed on the vehicle.
Thieves stole 659,880 vehicles in the United States in 2025, a 23% drop from 2024 and the lowest total in decades, according to the National Insurance Crime Bureau. One vehicle is still stolen every 48 seconds.
Does Car Insurance Cover Theft?
The only type of auto insurance that covers vehicle theft is comprehensive coverage. This is usually optional for personal vehicle owners.
If you don't have comprehensive coverage, your car insurance provider will not pay to replace a stolen vehicle. A car with no anti-theft device is an easier target for thieves.
Car Insurance does not cover the theft of personal belongings inside a stolen vehicle. You can file a claim with your home or renter's insurance provider to recover the loss.
Remember that if your deductible exceeds the value of the stolen items, filing a claim may not be worth it.
What Are The Best Types of Car Anti-Theft Devices?
Anti-theft devices fall into 3 groups that insurers recognize. Passive systems arm themselves, such as immobilizers, transponder keys, and alarms. Active devices require the driver to engage the device each time, such as steering wheel locks and kill switches. Tracking or recovery systems locate the car after a theft, such as GPS trackers and LoJack. Layering 1 device from each group gives the strongest protection and, with most carriers, the largest discount.
Passive Anti-Theft Systems
Automatic anti-theft devices, also known as passive devices, don't require you to do anything to activate them.
Many newer vehicles have built-in systems that engage when you turn off the ignition or lock the car. These devices improve vehicle security by preventing unauthorized access and deterring theft.
The most common types of passive anti-theft devices are listed below.
Engine Immobilizers: An immobilizer is an electronic system that stops the engine from starting unless the system reads the correct coded key or fob. A factory immobilizer works through the transponder key or smart key described below.
Alarm Systems: These engage when you turn off the ignition or close the car door. Some alarms have additional disabling features, like a computer chip in the ignition key, to prevent a thief from bypassing the key. However, while alarms can deter theft, frequent false alarms have reduced their effectiveness.
Dash Cams: Some dash cams offer continuous surveillance and can detect motion or impact while the vehicle is parked, recording evidence in case of theft or vandalism.
Vehicle tilt and Glass Break Sensors: These sensors trigger an alarm if they detect movement (e.g., someone trying to tow the car) or a broken window, alerting the owner and the thief.
Transponder Keys: These keys have a microchip that must be inside the vehicle for the ignition to start. The car can't be hot-wired without the correct key, making it much harder to steal.
Having these automatic security features gives you extra protection without lifting a finger, and you may even qualify for a car insurance discount on your policy.
Smart Keys and Relay Attacks
Smart keys, also called keyless entry systems, let the car start only when the car detects an authentic key fob. Most new cars come with smart keys. A dealership or locksmith can add smart keys to older models. Thieves defeat smart keys with relay attacks. A relay attack amplifies the fob's signal from inside your home so the car unlocks and starts. A Faraday pouch blocks the fob's radio signal and is the cheapest defense for a keyless car. Insurers treat the factory smart-key immobilizer as a qualifying device. The Faraday pouch itself does not earn a discount.
Active Anti-Theft Systems
Active anti-theft devices, also known as manual disabling devices, require driver activation each time they are used.
While Active devices demand regular engagement, they offer strong security measures that can deter thieves and prevent vehicle theft.
Common Active Anti-Theft Devices are listed below.
Steering Wheel Locks: These devices physically prevent the steering wheel from being turned, making it impossible for a potential thief to drive away. A steering wheel lock is a strong visual deterrent and easy to install and remove.
Brake Locks: A brake lock clamps onto the brake pedal, which prevents the pedal from being used. This makes the car undrivable even if a thief is able to start the engine.
Kill Switches: A kill switch cuts off the flow of electricity to essential engine components, like the ignition system or fuel pump, making it impossible for the car to start unless the owner deactivates the switch. A kill switch can be discreetly installed for added security.
Battery Disconnect Switches: This type of simple device cuts off the battery's power supply, preventing the vehicle from starting. They are cost-effective, easy to use, and highly effective against theft.
Tire Clamps (Wheel Clamps): Tire clamps attach to the car's wheel, preventing rotation and making the car undriveable.
Remote Locks: These locks allow vehicle owners to lock their cars using a key fob or mobile app, preventing anyone from entering or starting the car.
Drivers can add more security to their vehicles by installing active anti-theft devices. Active devices require manual activation but are highly effective at making vehicles more complicated to steal.
These devices can save you money on your monthly car insurance premiums.
GPS Tracking Systems
Tracking devices help find and recover stolen cars by sending real-time location data to the owner or the police.
Unlike other anti-theft devices, these tracking systems help recover the vehicle after it's stolen. Many offer remote monitoring, alerts, and even immobilization to prevent thieves from stealing the car.
Some Common Tracking and Recovery Systems are listed below.
GPS Trackers: GPS trackers provide real time location updates and allow you to track your vehicle through a mobile app. Some GPS trackers also send alerts via text or email if the car moves unexpectedly. Thieves will usually be discouraged if they see a GPS tracker inside the vehicle.
Vehicle Recovery Systems (LoJack): These systems use radio frequency technology to help police find stolen vehicles. Unlike GPS, which requires a clear satellite signal, LoJack works in underground parking garages and other hard to track areas. Some vehicle recovery systems will send an alert if the car is moved without the key fob inside. Vehicle recovery systems are expensive.
Subscription Based Tracking Services (OnStar): These services provide GPS tracking, remote engine disablement, and theft alerts. If a theft is reported, the system can prevent the engine from starting and give police the exact location of the vehicle. OnStar is the best-known subscription service, starting at $25 per month.
A tracking or recovery system raises the chance of getting your car back after a theft. More than 85% of stolen vehicles were recovered in 2023, and 34% were recovered the same day when the theft was reported within 24 hours, according to the Insurance Information Institute citing NICB data.
Remote Disabling Systems
A new type of theft prevention is a remote disabling system. These systems connect to your smartphone and can slow the car down, downshift gears, or lock the brakes.
While these systems can be effective, they are pricey and mainly used in commercial vehicles, not private cars.
VIN Etching
VIN etching is a simple and low cost way to deter vehicle theft. Using a stencil and chemical solution, you can permanently etch a vehicle's ID number onto the car's windows.
This helps the police identify stolen vehicles, and the thief can't sell the car without replacing the windows.
The effectiveness of VIN etching is that it makes the car traceable, so the thief has to replace the windows before they can sell it.
Audible Vehicle Alarm Anti-Theft Systems
Audible alarms are another subcategory of anti-theft devices. You have the choice between a passive car alarm or an active auto alarm.
You'll also be able to decide what you want the car alarm to do once it's activated.
One of the two options is a typical car alarm blare. It's a reliable car theft deterrent, but the auto insurance discounts are less than options like LoJack.
How to Tell If Your Car Already Has an Anti-Theft Device
Most cars built since the late 1990s left the factory with an immobilizer, and many also have a factory alarm. Check for a factory device before you buy an aftermarket device. The owner's manual lists factory security equipment under "security" or "immobilizer". A security light that blinks on the dash when the car is locked signals an active factory system. The window sticker or build sheet lists a security package. A VIN lookup with the manufacturer or a dealer's parts department also lists factory-fitted security equipment. Your insurer can confirm a factory device from the VIN.
How to Get an Anti-Theft Device Discount on Car Insurance
If your vehicle is equipped with a theft-prevention device, you may be eligible for an anti-theft discount on your car insurance policy, if your insurer offers it.
Availability and the amount of the discount vary by car insurance company and state, so check your insurance provider's website or speak with an insurance agent to confirm eligibility.
Some insurers require proof of installation before they apply the discount and may restrict eligibility to specific approved anti-theft devices.
Some states require insurers to offer an anti-theft discount to drivers who carry comprehensive coverage and have a qualifying device. State law sets the mandated minimum in those states. In every other state the discount is voluntary.
If your current insurer doesn't offer an anti-theft discount, you may want to shop for quotes from other providers to find the best deal.
Reviewing your car insurance policy regularly ensures you're getting the best rate and maximizing additional discounts.
What Qualifies as an Anti-Theft Device for a Car Insurance Company?
Car insurers recognize passive systems such as factory immobilizers and alarms, active devices such as steering wheel locks and kill switches, and tracking or recovery systems such as GPS and LoJack as eligible anti-theft devices, provided the device is permanently installed in the vehicle.
How Much Can Anti-Theft Devices Save on Auto Insurance Rates?
Anti-theft discounts range from about 5% to 30% off the comprehensive portion of your premium, depending on the insurer and the device. Basic alarms and immobilizers usually earn a discount at the low end of that range. Tracking and recovery systems such as LoJack earn the larger discounts.
Anti-theft discounts usually apply to comprehensive insurance policies only.
There is some debate about whether policyholders with only basic liability insurance will get similar discounts on their auto insurance premiums.
How Long Does an Anti-Theft Discount Last?
The anti-theft discount stays on the policy at every renewal for as long as the device remains installed and the vehicle keeps comprehensive coverage. The discount is a rating factor on each vehicle, not a one-time credit. The discount carries over when you renew or switch to a car with the same equipment. Each car on the policy needs its own qualifying device. Tell your insurer if you remove the device or drop comprehensive coverage, because the insurer removes the discount with it. Confirm the discount again when you change insurers.
Which Insurers Offer Anti-Theft Discounts?
Most major carriers offer an anti-theft discount. The discount amount and the eligible-device list differ by carrier.
Ask your Insurance Navy agent which of your quotes already includes the discount.
Do Factory Installed Car Alarms Qualify for Anti-Theft Insurance Discount?
Yes. Factory-installed alarms and immobilizers qualify for the anti-theft discount with most insurers. The manufacturer records factory equipment against the VIN, so the insurer can usually apply the discount without an installation receipt. An aftermarket device usually needs an installer's receipt.
Many drivers replace their original alarms with aftermarket systems that qualify them for additional anti-theft insurance discounts.
Check with your insurance agent today to see if you're eligible and how much you can save.
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