How Dark Can You Tint Your Car Windows? Legal Limits

There are only a few modifications one can perform on an automobile that is so practical yet non-intrusive, like window tinting. It gives your car an undeniable aesthetic upgrade, making it look a lot more menacing and, of course, the main reason why drivers install films, which is protection from glare and UV rays. Thanks to the massive car culture that exists, it comes as no surprise that car owners are free to tint their car windows. However, just how dark can you tint those windows? Let’s find out how far we can stretch until we hit the legal limit.

The Window Tinting Lingo

Before we talk about things like state laws and how dark car window tinting is allowed, let’s familiarise ourselves with the terminology of the window tinting world. This will be a quick read, we assure you.

1) Visible Light Transmission (VLT) Limits

The very first and arguably the most important term to remember is VLT, which refers to the percentage of light that must pass through the window. The lower the number, the darker the tint. The extremely dark limo tint is 5%, making it the darkest tint available on the market.

2) Reflectivity & Mirror Tints

Reflectivity, as you might have assumed, refers to how much light a tint reflects instead of absorbing. This is done using what is called mirror tints, and while these do look fantastic and serve the purpose of classic films, they end up being a hazard to other drivers as they can blind them.

3) Color Restrictions

The classic tint is usually black, but there are plenty of other colours available as well. However, from a legal standpoint, any color is allowed as long as the tint film maintains the required light transmission (VLT) levels on the regulated windows.

4) Certification & Sticker Requirements

Certain states require certified tint film that meets specific standards. Some also mandate a sticker on the driver’s side window proving legal compliance.

So, How Dark Can The Tints Go?

Let’s address the elephant in the room now, with all the terminology cleared up. How dark can window tints be, legally speaking? Well, in the UK, window tinting is regulated not on a state-to-state basis but by national law (the Road Vehicles (Construction and Use) Regulations 1986).

• Vehicles must allow at least 70% of light through the side windows and 75% of light through the windscreen.

• For the front windscreen, only a small non-obstructive tinted strip (often called a sun visor tint) is permitted at the top; the rest of the windscreen must meet the 75% light transmission requirement.

• There are, thankfully, no legal restrictions on the darkness levels of tinting for the rear side windows or rear windscreen.

Exceptions to the Rule

Exceptions are always there, and it seems car window tinting is no different. Unfortunately, unlike in the US, there is no medical exemption in the UK that allows an individual to install darker tints on their front windscreen or side windows, even with a doctor’s note. The UK has a singular law that applies nationwide, with no exceptions to the minimum Visible Light Transmission (VLT) standards (75% for the front windscreen and 70% for the front side windows), regardless of any medical need.

Manufacturer’s Tints

The only exception is factory-installed tints. Many SUVs, trucks, and vans come with factory-tinted rear windows (even Teslas). You might find yourself wondering about the legality of these tints, but since they are installed only after meeting safety standards and the approval of the government, they are legal. However, adding extra tint on top of the factory tint would result in a violation.

Conclusion

Installing darker-than-legal window tints will result in fines, and repeat offenders can even be asked to appear before a judge, so it's best to install tints that are legally allowed.