How Does Black Box Insurance Calculate Your Score?
Updated 16 October 2026 · 6 min read
What a black box or telematics app measures, how insurers turn it into a driving score, and simple ways to improve yours.
Quick answer: How Does Black Box Insurance Calculate Your Score?
Black box insurance scores you on how you drive, using a device or phone app that records speed, braking, acceleration, cornering, the time of day you drive and how far you go. Smooth, steady driving at sensible times earns a higher score, which can lower your premium.
Key takeaways
- Scores are based on speed, braking, acceleration, cornering, time and mileage.
- Each insurer weights these differently, so check your policy.
- Good scores can earn discounts; poor ones can cost you.
This guide is part of our full guide to car insurance for young and new drivers. You may also find these useful: black box insurance explained: is it worth it? and cheapest cars to insure for an 18 year old male.
What the black box records
A telematics device fitted to your car, a plug-in unit or a smartphone app tracks how the car is driven. Most record:
- Speed, compared with the speed limit for the road.
- Harsh braking and hard acceleration.
- Sharp cornering.
- The time of day you drive, with late-night trips often seen as higher risk.
- How many miles you drive and on what types of road.
How the score is worked out
The insurer turns this data into a score, often shown in an app. Each insurer uses its own formula and weights the factors differently, so one company might care most about speed while another focuses on night driving.
Your policy documents and app should explain what's measured. Read them so you know what counts against you.
What your score affects
Depending on the insurer, a good score may bring a lower renewal price, a refund or monthly rewards. A poor score can mean a higher renewal price, extra charges, or in serious cases the insurer cancelling the policy. Check your terms.
How to improve your score
Simple habits make a big difference:
- Stick to speed limits, including on fast roads.
- Brake and accelerate gently, and leave space ahead.
- Take corners and roundabouts smoothly.
- Avoid late-night driving where you can, especially if your policy has a curfew.
- Keep the app or device connected so trips are recorded properly.
This guide is general information, not financial advice.