UK window tint law, explained simply

The legal limits

UK rules are written as VLT — visible light transmission, meaning the share of light that must pass through the glass. The higher the number, the lighter the glass.

What happens if it's too dark

Front glass below the limit is a major fault at MOT, so the car fails until the film comes off. It is not a note or an advisory — the test is failed on that point alone.

On the road, an officer can issue a fixed penalty with points, and in serious cases a prohibition notice, which stops the car being used until the film is removed and the glass re-checked. Removing badly fitted film costs more than fitting it correctly in the first place.

Why "film plus glass" matters

A meter does not read the film on its own. It reads the film and the glass together. Modern cars already leave the factory with lightly tinted glass, so a film sold as 70% fitted onto glass that already reads 78% will not give you 70% — it will read lower.

That is why we do not promise a pass. We fit a high-clarity ceramic film at the front, then put a light meter on the finished glass and tell you the reading. Measured beats promised.

What we do

Front side windows and the windscreen strip are fitted within the legal limit and measured after fitting. Rear side windows and the rear screen are fitted as dark as you want them, because the law sets no limit behind the front seats.

If a car comes in with film that is already too dark at the front, we can take it off and refit it inside the limit. That is often the cheapest way out of a failed MOT.