What Does an ISO Rating Mean (for Car Insurance)?

Last Updated on February 5, 2026

In car insurance, an “ISO rating” usually refers to the vehicle symbol (sometimes called an ISO Symbol) used in many insurers’ pricing formulas. These symbols come from the former Insurance Services Office (ISO), which is now part of Verisk and provides rating data that insurers and rating bureaus use to help price risk.

Important: this is not the same “ISO” as the International Organization for Standardization. In auto insurance, an ISO/Verisk symbol is basically a way to say: “For this make/model/year, how expensive are the claims compared to other vehicles?”

Below is what an ISO rating means for car insurance, what impacts it, what doesn’t, and how you can use it to shop smarter.

• An “ISO rating” in auto insurance usually refers to a vehicle symbol used to estimate expected claim costs for a specific make/model/year.
• Higher vehicle symbols generally mean higher premiums—especially for collision and comprehensive—because the car is more expensive to repair, replace, or insure based on real-world losses.
• Your driving record, ZIP code, and garaging location affect your overall premium, but they don’t change the vehicle’s ISO symbol itself.
• The best way to “use” ISO symbols is to quote cars before you buy and compare similar vehicles, since insurance costs can vary widely even at similar sticker prices.

What Is an ISO Rating Symbol in Auto Insurance?

An ISO (Verisk) vehicle symbol is a code tied to a specific vehicle (usually by make, model, and model year). Insurers use that symbol to estimate expected losses—then convert that into part of your premium.

Think of it like a “cost index” for your vehicle. If a car tends to cost more to repair, gets stolen more often, or has higher claim payouts, its symbol relativity will typically be higher—so the vehicle portion of the rate goes up.

How an ISO Symbol Affects Your Car Insurance Price

Insurers don’t price a policy with only one number. Instead, they combine multiple pricing pieces—driver, location, coverages, and vehicle. The ISO symbol is mainly part of the vehicle piece.

In practical terms, ISO symbols commonly influence pricing for:

• Physical damage coverage (comprehensive and collision) — see collision and comprehensive coverage
• Liability coverage — see auto liability insurance
• Injury-related coverages like PIP/MedPay — see personal injury protection

That’s why two drivers with identical records can still get very different quotes if they drive different cars—your vehicle’s expected claim costs can shift the premium even when your “driver risk” is the same.

What Goes Into an ISO Rating Symbol?

ISO/Verisk symbols are built to reflect real-world loss experience for a vehicle series, not just the sticker price. While the exact formulas aren’t “consumer-facing,” these are the kinds of factors that typically push vehicle symbols up or down:

• Repair costs and parts pricing (including how complex the vehicle is to fix)
• Vehicle value and the cost to replace it after a total loss
• Claim frequency and severity for that make/model/year (how often it’s in claims and how expensive those claims are)
• Theft risk and how desirable the vehicle is to steal — see car insurance theft coverage
• Body style and performance (for example, some sports/performance trims are rated higher) — see do convertibles cost more to insure?
• Vehicle size and crash dynamics (for example, pricing often differs across sedans vs. SUVs) — see sedan vs. SUV insurance costs

If you’re shopping for a vehicle with lower insurance costs, start with models known for low repair costs—because repair severity is one of the most common drivers of higher premiums.

What Does NOT Affect Your Vehicle’s ISO Symbol?

An ISO symbol is about the vehicle, not you personally. It does not change because of:

• Your individual driving history (tickets, accidents, claims)
• Your “risk tier” or underwriting category
• Where you live and drive — see why your ZIP code matters for auto insurance
• Where the car is parked/garaged — see garage parking and insurance rates

Your insurer still uses those factors to price your policy—just not as part of the vehicle’s ISO symbol itself.

Do Cars Have More Than One ISO Symbol?

Often, yes. A vehicle can have different symbols (and different “relativities”) tied to different coverage types—because the loss patterns for liability aren’t always the same as the loss patterns for physical damage.

This is why you might see a bigger price jump for collision and comprehensive than for liability when you switch vehicles (or vice versa).

How to Use ISO Ratings to Get Cheaper Car Insurance

You usually can’t “change” a vehicle’s ISO symbol—but you can use the idea behind symbols to make smarter choices:

• Quote the car before you buy it. Use the VIN if possible (trim level matters).
• Compare similar vehicles. Two cars with similar MSRPs can have very different insurance costs depending on real-world losses.
• Choose safety + theft-deterrence wisely. Anti-theft features and safer designs can help, and some insurers offer anti-theft device discounts.
• Adjust coverages as your vehicle ages. Older cars may not need as much physical damage coverage, depending on value and finances.

And remember: the vehicle is only one part of the total premium. If you’re paying high rates due to your driving record, focus on improving your overall profile so you can move from high-risk to standard insurance over time.

Quick Note: ISO Ratings for Home Insurance (PPC)

ISO is also known in home insurance for the Public Protection Classification (PPC), which grades a community’s fire protection on a 1–10 scale. That PPC can influence home insurance pricing (and it may matter more if you bundle home and auto).

FAQs on ISO Ratings for Car Insurance

Final Word

An ISO rating in car insurance is a shorthand way to describe how insurers estimate vehicle-related claim costs. You can’t control your car’s symbol, but you can control how you shop: price the vehicle before you buy, compare similar models, and pick coverage levels that match your car’s value and your budget.