How Dark Can You Tint Car Windows in the UK? The Legal Limits

On a car first used on or after 1 April 1985, the front windscreen must let at least 75% of light through and the front side windows at least 70%. There are no rules for tinting the rear windscreen or rear passenger windows.

What are the legal limits for tinted windows?

The rules only cover the glass the driver looks through, and they depend on when the vehicle was first used:

• First used on or after 1 April 1985: front windscreen at least 75% of light, front side windows at least 70%.

• First used before 1 April 1985: front windscreen and front side windows both at least 70%.

The full rules are on GOV.UK.

Can I add tint film to my front windows?

In practice there is very little room. Car glass is not perfectly clear to begin with, so it already blocks some light before any film goes on. Even a light film on the front side windows can take the total below 70%.

If you are having front windows tinted, ask the fitter to measure the finished glass and confirm in writing that it meets the limit.

How dark can rear windows be?

As dark as you like. There is no legal limit for the rear windscreen or the rear passenger windows, which is why many cars and vans leave the factory with dark privacy glass behind the front seats.

What happens if my tints are too dark?

The police and the Driver and Vehicle Standards Agency (DVSA) use light measuring equipment at the roadside. If the windscreen or front side windows are tinted too much, you could get:

• a prohibition notice, which stops you using the vehicle on the road until the extra tint is removed;

• a penalty notice;

• a court summons.

It is also against the law to fit or sell glass, or a vehicle already fitted with glass, that breaks these rules.

What should I check when buying a car with tinted windows?

1. Work out whether the tint is factory glass or film added later. Film usually has a visible edge near the top of a wound-down window.

2. If the front side windows or windscreen have film on them, ask for proof that the glass has been measured.

3. Tell your insurer. Aftermarket tints are a modification, and insurers expect to be told about modifications.

Common questions

Is factory privacy glass legal?

Yes on the rear windows, where there is no limit. Front glass fitted by the manufacturer is made to meet the limits. Adding film on top of it is what causes problems.

Do the limits apply to older cars?

Yes, with one difference. A vehicle first used before 1 April 1985 needs 70% through the windscreen instead of 75%.

Who decides whether a tint is too dark?

The police or DVSA examiners, using a meter that measures how much light passes through the glass. It is not a matter of opinion.

Looking for your next car in Barnsley?

Browse the cars we have in stock at anycolourcar.com in Barnsley, South Yorkshire, or call the sales team on 01226 574410. For looking after the car you already have, see our car care page.

This guide is general information, not legal or financial advice. Updated October 2026.