Car groups 1 to 50: how they affect your premium

Car insurance groups run from 1 to 50. Cars in group 1 have the lowest price rating and cars in group 50 have the highest price rating, so the group is a shorthand for how expensive a car tends to be to repair and insure¹. The groups range from group 1, the cheapest cars to insure, all the way up to group 50, the most expensive².

The group is a rating of the car, not a quote for you. It feeds into the premium alongside your age, driving history, where you keep the car and the cover you choose. That is why two people driving the same group 20 car can be quoted very different prices, and why a low group does not guarantee a low premium.

This page explains what the 50 groups mean, how a car is placed in one, who decides, where to check your own car's group, and why the group your insurer uses can differ from the published rating.

Car insurance groups 1 to 50: lowest to highest price rating

The 50 groups are a ranking of how much a car is likely to cost an insurer to repair and replace, and how attractive it is to thieves. Group 1 sits at the bottom of that ranking and group 50 at the top¹. A car in a low group is not automatically cheap for every driver to insure, and a car in a high group is not automatically uninsurable, but the group gives a rough sense of where a model sits relative to others.

The rating is built from the car itself: what it costs to repair, how easy parts are to source, how it performs in a crash and how secure it is. A popular model with widely available, cheap parts tends to sit lower than a high-performance car with expensive, specialist components. Because the group is about the vehicle, it stays the same whoever is driving it, which is what makes it useful as a comparison between models before you buy.

Where the group matters most is at the point of choosing a car. Two models that look similar on a forecourt can sit many groups apart, and that gap shows up in quotes. It is one of the few parts of a car insurance premium a buyer can influence before they ever get behind the wheel.

The group is not the only thing that moves a premium. Insurers also price the driver, and the same car can be cheap for one person and expensive for another. For the wider picture of what goes into a quote, see how insurance premiums are worked out.

How a car's insurance group is decided

A car's group is decided by measuring the things that drive repair and theft costs. The panel looks at how much damage a car sustains in a low-speed impact, how much the parts cost, how long repairs take and how secure the car is against theft. Those measures are combined into a single group from 1 to 50.

The result is a rating that reflects the car's design and its parts, not the driver. A model with expensive bumpers, complex electronics or hard-to-source components will rate higher than a simpler car, because a minor bump costs more to put right. Security matters too: a car that is harder to steal rates better than one that is a known target.

Because the inputs change, groups are not fixed forever. Parts prices move, new security technology arrives and repair methods change, so a model's rating can be reviewed and can shift over time. That is one reason a group quoted in an old buying guide may not match the group an insurer uses today.

The group is also only one of the levers on a premium. Insurers reduce premiums for things like parking in a garage or driveway, Thatcham-approved security devices, low annual mileage, a cheap-to-repair popular model, advanced driving training such as Pass Plus, paying annually and a no claims discount⁴. Several of those overlap with what the group is measuring, which is why a low group car plus a secure parking spot can move a quote more than the group alone.

The Group Rating Panel and Thatcham Research

Car insurance groups are broadly set by the Group Rating Panel and administered by Thatcham Research². The Association of British Insurers and others sit on the panel, which decides the groups using monthly information from the Motor Insurance Repair Research Centre in Thatcham¹.

That structure matters to a consumer in one practical way: the group is an industry rating, not a regulator's rule. It is a shared reference point that insurers can choose to follow or depart from. The panel produces the rating; individual insurers decide how much weight to give it when they price your policy.

Thatcham Research is the body that carries out the crash, repair and security testing behind the ratings. Its findings feed the panel, which then places each car in a group. Because the testing is ongoing, the ratings can be updated as new models arrive and as existing ones are reassessed.

The panel's output is published so that buyers and insurers can see where a car sits. But it is a starting point, not a price. The next section explains why the group you see quoted and the group your insurer applies can be two different numbers.

How to find your car's insurance group

There are a few places to look. The Association of British Insurers publishes group ratings, and the group is often listed in a car's specification when it is sold. Insurers also publish the groups they use for the cars they cover, and a broker can look it up for you.

If you cannot find the group, ask. A broker will help you decide what type of insurance and level of cover you need and recommend a suitable policy at a price you can afford⁶. The British Insurance Brokers' Association runs a Find Insurance website that can help you find a broker⁷. For the difference between going through a broker and buying direct, see using a broker or buying direct from an insurer.

When you are comparing cars, the group is one of several things to check alongside the model's repair costs and security. If you are buying used, the group is worth confirming against the insurer you plan to use, because that is the number that will actually feed your quote.

The group is a guideline: your insurer may use a different one

The published group is a guideline only, and the group an insurer uses may be different². Insurers build their own view of a model's repair costs, theft risk and claims experience, so they can rate a car above or below its published group. The group that applies to your policy is the one your insurer quotes on.

This is the single most important thing to understand about the 50 groups. They are a common language for comparing cars, not a price list. Two insurers can place the same car in different groups and quote accordingly, which is why shopping around matters more than the group number alone.

The group also interacts with the driver. A young driver's premium is likely to be higher due to the higher risk posed⁸, and premiums usually start to increase once you are 70 and go up significantly after the age of 80⁴. So the same car can be cheap for one driver and expensive for another, even at the same group.

If you modify your car, the group can change too. Many insurers will insure modified cars as long as the details of the changes made are disclosed³. Anything the insurer says is a modification counts, and where a car is non-standard in any way, the insurer is the one to check with³. Not telling your insurer about modifications could invalidate your insurance³. For more on what must be reported, see changes you must tell your insurer about mid-policy.

What the group does not tell you

The group says nothing about your own risk profile, and that is where most of a premium is decided. Your age, claims history, where you live, how many miles you drive and the cover you pick all sit alongside the group in the calculation. A group 1 car driven by a newly qualified driver can cost more to insure than a group 20 car driven by someone with years of no claims.

The level of cover you choose also changes the price. The minimum level of cover you need is third party insurance, which covers injuring someone or damaging another car but not repairs to your own car⁴. Comprehensive cover costs more because it adds cover for your own vehicle. For the difference, see third party or comprehensive car insurance.

Add-ons sit on top of the group and the cover level. Breakdown cover, legal expenses and GAP insurance are separate products with their own prices, and they are not part of the group rating. GAP insurance covers the difference between a car insurer's payout and the price paid for the vehicle⁹. For how these are priced and sold, see breakdown cover explained and GAP cover.

Finally, the group does not tell you what a claim will cost you. Excess, no claims discount and how a claim is handled are separate from the rating. For the wider picture, see how car insurance works.

Where the group fits in a quote

The group is one input among many, and it is the one tied to the car rather than the driver. When you are choosing between two models, the group is a useful first filter: it tells you which car is likely to cost more to repair and insure before you get a quote. When you are choosing between insurers for the same car, the group is less useful, because each insurer applies its own rating.

The practical approach is to use the group to narrow your shortlist, then get quotes for the cars that make it through. The group will not predict the number, but it will tell you which way the number is likely to move.

If a quote comes back higher than the group suggested, the reason is usually the driver, not the car. Age, claims history and where the car is kept do most of the work. For what drives those differences, see how insurance premiums are worked out and insurance pricing rules.

If you are unhappy with how an insurer has rated your car or handled your policy, you can complain. For how that works and where to take it, see complaining about an insurer and the Financial Ombudsman Service.