Are LED Upgrade Bulbs Road Legal?

Let’s start with the short answer: Technically, LED upgrade bulbs are not road legal.

To find out why, we need to delve into the specifics of the legislation…a boring job but we’ve done it for you! (section 4 & 5) states that dipped beam and main beam headlights are required to have an approval mark (usually E mark) or a British Standard mark. For nearly every other application on your vehicle, an approval mark is also required.

The legislation is quite detailed and in-depth so we won’t go into it all here. But for example, stop lamp bulbs are required by law to operate between 15 and 36 watts. The full legislation that covers halogen and filament bulbs is ECE Regulation 37 and is 217 pages long!

This may feel like the legislation is a bit pedantic but it’s worth noting that these rules are in place for your safety and the safety of others on or near the roadside.

That’s Fine, Just E Mark the LED Upgrade Bulbs…right?

Unfortunately, not. LED upgrade bulbs can’t be classed as road legal because they cannot be E marked or have the British Standard mark.

The reason that LED upgrade bulbs can’t be E marked is simply because no legislation exists for the use of LED technology in a headlight unit built for halogens.

Headlight units are manufactured around a specific technology. Let’s say that the bulbs for your dipped beam are H7. The "H" stands for Halogen meaning the headlight unit has been purposely built for a halogen bulb. The number that follows the "H" indicates that only a H bulb with the same number can be installed.

The aftermarket LED bulbs that are available have only ever been designed to replace their halogen counter parts and without supporting legislation, they can’t achieve an E mark.

What is the difference in E marks?

E marking is a very strict process that involves a series of rigorous tests and criteria that a bulb will have to meet.

The number that follows the 'E' represents the country that has approved the mark for that product. That doesn’t mean it was manufactured or tested in that country, it just means that the country signed it off as meeting the requirements.

Technically any product that has an E mark should all be up to the same standard, regardless of the country approval, as they all follow the same rules of the ECE regulation. However, in practice, how strict countries uphold their E mark standards varies massively.

Germany is by far the strictest country for allowing products to be marked with their "E1". This means products with this number tend to be more reliably up to standard. Other countries don’t hold such strict standards and checks, so it’s more common for those to be less reliable.

If you’re interested in learning more about E marks, then Truck Electrics has written a fantastic explanation..

There Is Still Hope for Change

Unfortunately, the legislation is old and outdated. Written in 1986, there are still many things that need to be changed.

For example, the legislation doesn’t take new technologies into account. It was written at a time when the idea of replacing one technology for another within the same headlight unit just wasn’t a thing.

According to the legislation – in order to get enough light output for a stop light, you would need a minimum of 15 watts. This would make sense for a filament bulb however an LED would produce an immense amount of light at 15 watts. Every time you press the brakes, you would be blinding the person behind you.

Perhaps a better way to set the standards is to use metrics that transcend technology. For example, instead of a minimum or maximum wattage, lumens would be a better metric. Lumens is a measure of the total amount of light emitted.

With a better thought out set of rules, ensuring safety and reliability standards are met, without restricting it to one light technology, should absolutely be possible.

Can LED Bulbs Still Pass An MOT?

Regulations regarding lighting and MOTs is a completely different kettle of fish.

The Road Vehicles Lighting Regulations states a bulb needs to be E marked, approved or have the correct wattage in order to be road legal. However, this is not a requirement that is checked by an MOT testing station. This is probably due to it being an almost impossible (or at least insanely lengthy) task. If they have to check approval marks on bulbs, they would have to do this for every component on the car! That’s just not going to happen.

Instead, the MOT stations adhere to the MOT Testing Guides.

What do the MOT Guides say about LED bulbs

"Check HID and LED headlamps for mandatory levelling and cleaning devices" and the assessor needs to check the lighting for "Operation", "Security"and "Condition" which essentially means that they need to make sure that they work and are fitted correctly.

That’s it. Nothing else is mentioned regarding the use of LED headlight bulbs.

Now you would be forgiven for thinking that aftermarket LED bulbs would therefore fail an MOT as you would not have a self-levelling or headlight cleaning system installed. However Section 4.1.5 of the MOT inspection manual states that not all vehicles are fitted with a levelling device so if your vehicle doesn’t have one, it would not be tested.

Brexit 2021 Update

Please note that since January 2021, the MOT Inspection manual has been updated to include LED bulbs.

Section 4.1.4 now states the following:
"Existing halogen headlamp units should not be converted to be used with high intensity discharge (HID) or light emitting diode (LED) bulbs. If such a conversion has been done, you must fail the headlamp."

This is a brand-new update that seems to only focus on headlights.

There are no mentions to fail other LED bulbs such as brake lights, tail lights or reversing lights.

With no other mention of after-market LEDs in the MOT guidelines, all that is left is for them to check is that the beam pattern is correct and the colour of the light is predominantly white, white with a blue tint or yellow. Any good quality after-market LED bulbs will meet this criterion.

As long as the beam pattern and the colour of the light is correct – then there is no reason an LED upgrade bulb will fail an MOT.

Should I Try Sealed LED Headlight Units?

Many people looking to purchase a new car or van will soon be offered the chance to have sealed LED headlight units as an option from a dealership.

Newer models might even have this as standard.

What Is A Sealed LED Unit?

A sealed LED headlight is a unit where the LEDs are completely integrated with the headlight unit itself. It cannot be repaired, opened or modified. Therefore, you cannot replace the LED’s if one fails like you can with current halogen and HID bulbs. The entire unit will need to be replaced!

To us this seems like a very wasteful idea.

As I’m sure you’ve guessed, these types of headlights are extremely costly. If you do have one fail or break for any reason, your bank balance might be in trouble!

If one bulb goes then the whole headlight will need to be replaced which will likely cost between £500 – £1000. As with all lighting technology, the colour and brightness will shift over time. Therefore, depending on how old the unit is, you may even need to buy 2 units to ensure matching performance from both sides.,/p>

Not only is cost an issue but you have no choice to change the light output performance. Some bulbs inside the unit could still be under-performing, basic LED bulbs. We are already getting calls from people looking to upgrade them as the light output is inadequate. It’s very disappointing to break the news that no upgrades are possible.

The only option would be to upgrade your sealed LED headlights entirely with another after-market set. But currently the cost to do this can fall between £1,000 to £2,500. These costs are reflective of this technology being fairly new to the automotive market. Of course, as the demand increases, the costs should reduce but it will always be a more expensive upgrade than is available for halogen and HID units.

Why Do LED Bulbs Blind Other Road Users?

We’ve all experienced blinding lights from other road users before. It’s definitely not something new.

Aftermarket LED bulbs tend to get the blame a lot on forums, Facebook or blog articles. Unfortunately, a lot of the blame is out of ignorance.

There are a number of factors that could be at fault:

Cheap aftermarket bulbs

Purchasing cheap bulbs can be dangerous for you and other road users.

These cheap bulbs might be dangerously bright or throw out the wrong beam pattern that can blind oncoming traffic and get you pulled over by the police.

Always aim to purchase any aftermarket bulbs from reputable brands such as OSRAM, Philips or Twenty20.

Incorrectly fitted bulbs

Sometimes the person who has fitted the bulbs has done so incorrectly. The beam pattern might be wrong and in turn, blinds other drivers. We’ve seen bulbs put in upside down and at all sorts of funny angles. Just because it’s clipped in place, it doesn’t mean it’s definitely in correctly.

Vehicle Height Difference

With so many 4×4’s and SUV’s on the road, there is a greater chance to get caught out with a height difference.

This is typically due to the manual-levelling of the drivers’ headlight bulbs. In most modern vehicles, a small dial can be adjusted that raises or lowers the beam pattern of your headlights. When vehicles that are high off the ground adjust this setting, it can often blind other road users.

There is a surprising number of negative reviews and articles from reputable platforms that are simply misinformed or unaware why there is an issue with their bulb.

For example, a review back in 2018 told readers not to buy aftermarket LED’s because "They will dazzle, because the light source is in the wrong place relative to the reflector…." – While this viewpoint reflects the poor quality and cheaper end of the market, it doesn’t take into account the performance improvements you would see from quality brands.


As we conclude this article – aftermarket LED bulbs are not road legal according to the Road Vehicles Lighting Regulations as they are not E marked.

MOT testing centres will now fail LED upgrade bulbs in your headlights but the guidelines state nothing about other LED bulbs in your vehicle.

There is never a guarantee that your vehicle will pass an MOT if you purchase cheap or faulty products so always ensure that you purchase quality branded LED bulbs from reputable sellers.

We believe that the system for car bulbs is vastly outdated. The Road Vehicles Lighting Regulations 1989 is based on old technology and doesn’t account for newer technologies like LED’s. The regulations are not in-line with current MOT testing guidelines and creates a confusing message for people looking to purchase these products.

Sealed LED units might seem like a good option when buying a car or van but consider the costs for the future.