Every car sold in the UK is assigned to one of 50 insurance groups — 1 being cheapest to insure, 50 being the most expensive. Groups are set by the Thatcham Research Automotive Risk Intelligence (ABI/GTA) system and based on repair costs, new car value, performance, security, and parts availability. A new driver in a group 1–10 car can pay significantly less than the same driver in a group 30+ car — sometimes thousands of pounds a year — so checking the group before you buy is one of the most effective ways to manage insurance costs.
Insurance group rating factors
| Factor | Effect on group rating |
|---|---|
| New car value | Higher value = higher group |
| Repair time and parts cost | Expensive/slow-to-repair cars rated higher |
| Performance (0–60, top speed) | Faster cars consistently rated higher |
| Bumper/safety feature compatibility | Euro NCAP-aligned systems reduce group |
| Security (alarms, immobilisers) | Factory-fitted Thatcham-rated security lowers group |
| Parts price index | Cheaper, widely available parts = lower group |
What insurance groups are and who sets them
Every car model available in the UK — and most variants within a model — is rated by Thatcham Research on behalf of the Association of British Insurers (ABI) and the Group Rating Panel. The result is a number between 1 and 50. Insurers are not legally bound to use this number directly, but virtually all UK insurers refer to it as a primary input when pricing policies. A group 1 car is the benchmark for low insurance cost; a group 50 car is at the extreme of high-cost cover.
Groups changed from a 1–20 scale to 1–50 in 2009 to allow more precision. You will still see some older sources using the 20-group system, so always verify which scale a figure refers to.
The seven main rating factors
Thatcham evaluates each vehicle on a consistent set of criteria. Understanding them helps explain why two superficially similar cars can land in very different groups:
- Damage and parts costs: The biggest driver of group placement. If a car's commonly damaged parts (bumpers, lights, bonnets) are expensive to source or fit, the group rises. Some manufacturers design bumpers that are incompatible with industry-standard repair equipment, pushing up labour time.
- Repair time: Thatcham tests how long standard repairs take at average labour rates. A car that takes twice as long to repair a front-end knock costs twice as much in labour.
- New car price: A higher list price increases replacement cost and theft attractiveness, raising the group.
- Performance: Acceleration and top speed correlate with accident frequency and severity. Sporty variants of the same model sit in higher groups than standard trims.
- Car security: Vehicles with Thatcham Category 1 (alarm + immobiliser) or Category 2 (immobiliser only) security devices are rated lower than vehicles without factory-fitted systems.
- Bumper compatibility: Cars designed so their bumpers align with standard impact heights cause less damage in low-speed collisions with other vehicles, reducing repair claims.
- Safety features: Cars with autonomous emergency braking (AEB) and other ADAS features that reduce accident frequency can be assigned to a lower group as part of the ABI's recognition of active safety technology.
How to find the group for any car
The definitive source is Parkers (parkers.co.uk) or the Thatcham Research website. Both let you search by make, model, year, and trim. When comparing cars to buy, check the specific trim level — a basic model and a sport variant of the same car can sit eight to fifteen groups apart.
Insurance group is a free, pre-purchase check that takes two minutes. On a car in group 40 vs group 20, the annual premium difference for a young driver can exceed £1,000. Always look up the group alongside running costs and fuel economy.
What insurance groups mean for different drivers
- New and young drivers: insurers weight performance risk heavily for drivers under 25. A group 1–10 car does not just save money on the group — it also avoids insurer surcharges that apply when a young driver insures a high-performance model.
- Experienced drivers with a full NCB: the group gap matters less in absolute terms because NCB brings premiums down overall, but moving from group 15 to group 30 still produces a meaningful premium difference.
- Modified cars: modifications that increase performance or change the car's specifications typically push the effective insurance group upward, even if the base model is low-rated. Insurers may decline cover or charge a significant loading.
- Classic and historic vehicles: vehicles pre-dating the group rating system or outside mainstream repair networks are not assigned standard groups; specialist insurers value and price them differently.
Groups and what they typically look like (illustrative ranges)
| Group range | Typical vehicles | Notes |
|---|---|---|
| 1–10 | City cars, entry superminis (e.g. Fiat Panda, VW Polo base trim) | Lowest premiums; best for new drivers |
| 11–20 | Family hatchbacks, standard SUVs | Moderate premiums; wide choice |
| 21–30 | Mid-size estate/SUV, sports-trim hatchbacks | Noticeable premium step for young drivers |
| 31–40 | Performance variants, prestige saloons | High premiums; NCB helps but does not offset group fully |
| 41–50 | Supercars, high-performance exotics, high-value sports cars | Specialist insurers often required |
Frequently asked questions
Can I change the insurance group of my car?
Do insurance groups affect all insurers equally?
Does a car's group change over time?
Is a higher group always a worse choice?
Where can I look up the insurance group of a specific car?
Sources & further reading
- Thatcham Research — Vehicle Security and Group Ratings
- Parkers — Car Insurance Groups Explained
- Association of British Insurers — Motor Insurance
Figures, prices and policy details were current at the last-updated date above. Automotive pricing, incentives and regulations change frequently — verify time-sensitive details with the linked primary sources. Read our editorial policy and fact-checking standards.
