How Do Auto Insurance Companies Determine Fault?

How auto insurance companies determine fault only applies if you live in an at-fault state. In at-fault states, the person responsible for the accident will pay for injuries and damages sustained by the other party. Auto insurance companies determine fault by analyzing police reports, witness testimony, and vehicle damage. You can contest how a car insurance company determines fault, but you will be responsible for your own legal fees.

Free Auto Insurance Comparison

secured lock Secured with SHA-256 Encryption

Rachel Bodine graduated from college with a BA in English. She has since worked as a Feature Writer in the insurance industry and gained a deep knowledge of state and countrywide insurance laws and rates. Her research and writing focus on helping readers understand their insurance coverage and how to find savings. Her expert advice on insurance has been featured on sites like PhotoEnforced, All...

Full Bio →

Written by Rachel Bodine
Insurance Feature Writer Rachel Bodine

Leslie Kasperowicz holds a BA in Social Sciences from the University of Winnipeg. She spent several years as a Farmers Insurance CSR, gaining a solid understanding of insurance products including home, life, auto, and commercial and working directly with insurance customers to understand their needs. She has since used that knowledge in her more than ten years as a writer, largely in the insurance...

Full Bio →

Reviewed by Leslie Kasperowicz
Farmers CSR for 4 Years Leslie Kasperowicz

UPDATED: Mar 11, 2022

Advertiser Disclosure

It’s all about you. We want to help you make the right coverage choices.

Advertiser Disclosure: We strive to help you make confident auto insurance decisions. Comparison shopping should be easy. We are not affiliated with any one auto insurance provider and cannot guarantee quotes from any single provider.

Our insurance industry partnerships don’t influence our content. Our opinions are our own. To compare quotes from many different companies please enter your ZIP code on this page to use the free quote tool. The more quotes you compare, the more chances to save.

Editorial Guidelines: We are a free online resource for anyone interested in learning more about auto insurance. Our goal is to be an objective, third-party resource for everything auto insurance related. We update our site regularly, and all content is reviewed by auto insurance experts.

In most states, fault is a crucial part of the auto insurance claims process. When two or more vehicles collide, insurance companies will investigate the accident to determine who is at-fault. In some cases, one driver is entirely at-fault while the other driver is not at-fault. In other cases, fault is split between drivers.

How do car insurance companies determine fault? Keep reading to find out.

No-Fault States Versus Tort States

12 states in America are no-fault states, which means that drivers are required to carry personal injury protection insurance. This insurance covers your medical expenses regardless of whether or not you were at-fault. If someone rear-ends you in a no-fault state, for example, and causes injuries, then you would use your own car insurance to cover your medical expenses, even though the other driver would be entirely at-fault.

Most states in America, however, are ‘tort’ states. In a tort state, the at-fault driver’s car insurance will be used to cover the car repairs, medical expenses, and other damages following an accident. Most states in America are tort states.

Compare over 200 auto insurance companies at once!

secured lock Secured with SHA-256 Encryption

How Car Insurance Companies Determine Which Driver is At-Fault

Car insurance companies use a number of different strategies and investigative techniques to determine which driver was at-fault in an accident. These strategies vary widely from accident to accident, but generally include the following:

Reading Police Reports

Insurance companies will use a police report as one of the most important pieces of evidence when determining who is at-fault. The police report is the official summary of what transpired. It tends to be more reliable than the versions provided by other drivers involved with the collision.

After an accident, drivers often have two different versions of the same accident. One driver might be deliberately lying to avoid blame, for example. Or, it’s entirely possible that drivers recollect the accident in two different ways. One driver might have been blinded by the sun when driving through an intersection, for example, while another driver might have seen a green light and a clear intersection.

The police report summarizes the incident according to trustworthy law enforcement officials. It gives a clear idea of who erred, free of any conflicts of interest or personal biases. After many accidents, the police report breaks the “my story versus their story” tie, giving insurance companies the best idea of who actually caused the accident.

Analyzing Gathered Evidence

Drivers, police officers, and pedestrians gather evidence after a car accident. You might take photos of the other driver’s front bumper, for example, or photos of the intersection. You might have recorded an interview with pedestrians at the scene, collected their names and contact information, and gathered other evidence.

All of this evidence could play a role in determining fault. Generally, it’s a good idea to collect as much evidence as possible. Sometimes, even the smallest photo – like the photo of skid prints beginning 50 feet before the site of the accident – can vindicate a driver who would otherwise have been declared at-fault.

After an accident, we recommend doing the following:

  • Get the names and contact information of any witnesses
  • Take pictures before leaving the scene
  • Call the police and have them write a police report

Ultimately, it’s a good idea to provide any evidence to the insurance company that supports your story of how the accident occurred. The insurance company will use your evidence – and all other gathered evidence – to ultimately determine who was at-fault.

Analyzing Vehicle Damage

In some cases, car insurance adjusters will analyze the site of vehicle damage to determine who is at-fault.

If the other driver hits you on the passenger side, for example, then the other driver may be more likely to be found at-fault. Alternatively, if you have damage to your front bumper and nowhere else, then you might be declared at-fault.

Or, consider a situation where a driver makes a dangerous left turn in front of you. Most drivers in this situation will attempt to swerve right to avoid hitting the driver cutting in front of them. That means the damage will be on the left front corner of your vehicle or left front side. The insurance company could use this damage to prove that you attempted to swerve out of the way and that the other driver wasn’t paying sufficient attention.

Shared Fault and Fault Percentages

Fault percentages can break down in a number of different ways:

100% / 0%: One driver was entirely at-fault for the accident, while the other driver was entirely not-at-fault.

50% / 50%: Both drivers are equally at-fault for the accident.

XX% / XX%: There are all different types of fault percentage breakdowns possible after an accident, ranging from 90 /10 to 60 /40 to anything else.

When fault in an accident is shared, it means insurance companies will be charging their respective drivers increased insurance premiums after the accident. If fault is not equally split, then drivers will be awarded compensation based on their at-fault percentage.

What Happens If I Disagree with Fault Determination?

In many cases, drivers will disagree with the fault determination of their insurance company. As part of your insurance policy contract, you have the right to disagree with a fault determination and appeal the decision.

Insurance companies have different procedures for appealing a decision. Sometimes, a mediator or an attorney may need to be brought in to resolve the dispute. You might even have to file a complaint with your insurer or your state’s insurance department. Contact your insurance company to discover the dispute resolution process.

Compare over 200 auto insurance companies at once!

secured lock Secured with SHA-256 Encryption

Conclusion: What Happens If I’m At-Fault?

After their investigation, the insurance company will determine which driver is at-fault and which driver is not at-fault. If you are at-fault, then your car insurance policy will be used to cover the medical expenses, property damage, and other expenses of the other driver. If you are not at-fault, then the other driver’s car insurance will cover your own expenses.

An at-fault accident may raise insurance prices, while a not-at-fault accident may not. Consider comparing car insurance quotes after an at-fault accident to ensure you’re getting the best deal on car insurance.

Free Auto Insurance Comparison

Compare over 200 auto insurance companies at once!

secured lock Secured with SHA-256 Encryption