Euro Emissions Standards Explained: What Euro 1 to Euro 7 Mean for Your Car

If you're thinking about buying your next car, you've probably heard about Euro emissions standards. They were introduced to help improve the air quality across the UK and Europe, and they're worth getting your head around before you decide on a vehicle.

Since they first appeared in 1992, these standards have made a real difference to our air and our health. But what exactly are they, and what do they mean for you when you're looking for a used car?

Let's dive into the world of Euro emissions standards and find out why they're so important.

What are the Euro emission standards?

Think of Euro emissions standards as a set of rules for car manufacturers. Their main job is to limit the harmful stuff that comes out of a car's exhaust, making vehicles cleaner and kinder to the environment.

The first standard, Euro 1, rolled out in 1992. It meant that all new cars had to have a catalytic converter fitted. Since then, the rules have been updated several times, with each new standard getting a bit stricter on vehicle emissions.

Why were the Euro emission standards introduced?

The standards were brought in to cut down on the harmful toxins in the exhaust fumes from petrol and diesel cars, vans, and motorbikes. These fumes contain things like nitrogen oxides (NOx), carbon monoxide (CO), and other tiny particles that aren't great for the planet or for us.

And the good news is, it's working! Data shows that since the early 90s, carbon monoxide levels from cars have dropped significantly. We've also seen big reductions in nitrogen oxides and other particulate matter, which is great for our lungs. For example, modern diesel cars are now fitted with diesel particulate filters (DPFs) that capture almost all of the sooty particles from the exhaust. It's a huge step forward for cleaner air.

What Euro standard is my car?

The Euro standard your car meets usually depends on when it was first registered. If your car is older than the standard it was meant to meet, it doesn't have to comply.

Here's a quick way to work it out, based on when a car was first registered:

Why do I need to know my car's Euro emission standard?

Knowing your car's Euro standard is useful for a couple of reasons. First, it gives you a better idea of what to expect from the car. For example, knowing that all Euro 5 and 6 diesel cars must have a DPF helps you know what to look for when checking a used car, as these can sometimes be a point of failure on an MOT.

More importantly, it affects where you can drive without paying a charge. London's Ultra Low Emission Zone (ULEZ) charges non-compliant vehicles £12.50 a day, and it's worth being clear that ULEZ is specifically a London scheme. Other UK cities, including Birmingham, Bristol, Bradford, Portsmouth and Sheffield, run their own separately branded Clean Air Zones instead, generally using similar Euro-standard thresholds but with their own boundaries and charges, so it's worth checking before you travel rather than assuming the same rules apply everywhere.

As a general rule, petrol cars that meet Euro 4 standards and diesel cars that meet Euro 6 standards are exempt from these charges. Fully electric cars are exempt too, of course. If your vehicle doesn't meet these standards, you'll need to pay a daily fee to drive in these zones.

How to get proof of your vehicle's Euro emission standards

Besides using the registration date, there are other ways to confirm your car's Euro standard. Newer V5C logbooks include a Type Approval Number in section D.2, but it isn't as simple as reading "Euro 6" straight off the document — that number has to be cross-referenced against the manufacturer's data to work out the actual Euro standard. Sometimes you'll also find a Euro rating on a sticker inside the driver or passenger door frame.

For a quicker answer, especially if you just need to know whether you'll pay a charge, TfL runs its own vehicle checker where you enter your registration number and it tells you directly whether you're ULEZ compliant. If you're buying a car from a dealer, they'll also be able to give you this information. While our guide is a good starting point, checking the official documents, or a car registration check, is always the best way to be certain.

Euro 1 emission standards

Introduced in 1992, Euro 1 was the game-changer. It required all new petrol cars to use unleaded fuel and be fitted with catalytic converters to slash carbon monoxide emissions.

Euro 1 emission limits

Euro 2 emission standards

In 1996, Euro 2 arrived and set different limits for petrol and diesel cars. It tightened the rules on carbon monoxide and other pollutants for both fuel types.

Euro 2 emission limits

Euro 3 emission standards

January 2000 saw the arrival of Euro 3. The testing process was updated, and for the first time, separate limits were set for nitrogen oxides (NOx) in diesel engines and for hydrocarbons and NOx in petrol engines.

Euro 3 emission limits

Euro 3 split hydrocarbons and NOx into separate figures for petrol cars for the first time; diesel cars kept a combined HC+NOx limit alongside a standalone NOx figure:

Euro 4 emission standards

By 2005, diesel cars were becoming very popular. The Euro 4 standard brought in tougher limits specifically for diesel emissions. This is also when many diesel cars started being fitted with particulate filters to trap soot.

Euro 4 emission limits

Euro 5 emission standards

Euro 5, introduced in 2009, put an even bigger focus on diesel cars. The limit on NOx was cut significantly, and DPFs became a requirement for all new diesel cars to meet the rules, capturing 99% of nasty particles.

Euro 5 emission limits

Euro 5 cut diesel NOx significantly and, for the first time, added a particle number (PN) limit alongside the particulate mass (PM) limit, effectively requiring a diesel particulate filter to meet the rules:

Euro 6 emission standards

Euro 6 emission limits

Euro 6 applied to newly type-approved cars from September 2014 and to all new registrations from 1 September 2015. It brought another major cut to diesel NOx, down to 0.08g/km, a 67% reduction on the Euro 5 diesel figure, and extended the particulate mass and particle number limits to direct-injection petrol engines too:

Many modern diesel cars use AdBlue to help hit that 0.08g/km NOx limit. Our AdBlue guide explains exactly how it works, if you want the detail.

Euro 7 emission standards

The next chapter, Euro 7, takes a two-stage approach. It applies to newly launched vehicle types from 29 November 2026, with all new cars and vans needing to comply by November 2027 or be withdrawn from sale.

Rather than just tightening tailpipe limits further, Euro 7 broadens the net to cover pollution sources that older standards ignored entirely, including particles thrown off by brakes and tyres, and it will require electric and plug-in hybrid batteries to be tested for their long-term durability and performance. Manufacturers will also need to show that cars keep meeting the rules for 10 years or 124,000 miles (200,000km) of real-world driving, not just in a lab when the car is new.

As with every previous update, cars already on the road won't be reclassified under Euro 7. New safety and diagnostic sensors should also make it easier to catch emissions-related faults early, so problems get fixed rather than ignored.

Frequently Asked Questions

What is the current Euro emission standard?

Right now, the latest Euro emissions standard in force is Euro 6 for both petrol and diesel cars, though that's due to start changing from November 2026 as Euro 7 begins applying to newly launched models. If you're planning on driving in London's ULEZ, you'll need at least a Euro 4 petrol or Euro 6 diesel vehicle to avoid paying the daily charge.

What cars are ULEZ compliant?

For London's Ultra Low Emission Zone specifically, petrol cars need to meet the Euro 4 standard and diesel cars need to meet Euro 6 to avoid the £12.50 daily charge. Electric vehicles are exempt entirely. Other UK cities run their own separate Clean Air Zones rather than a ULEZ, generally using similar thresholds but with their own boundaries and charges, so it's worth checking the specific scheme for wherever you're driving.

Can I make my car Euro 6 compliant?

Not really, in most cases. A car's Euro standard is fixed by its original type approval and recorded on its V5C, and fitting aftermarket emissions equipment doesn't change that official record. The government's Clean Vehicle Retrofit Accreditation Scheme does allow certified retrofits for buses, coaches, HGVs, vans and minibuses, but there's currently no accredited retrofit route for ordinary private cars, whatever a garage might offer to fit. If your current car doesn't meet the standard you need, the realistic options are paying the daily charge when you need to drive into a zone, or changing to a compliant car.

Does Brexit have an impact on Euro emission standards?

No worries here, Euro emissions standards are sticking around in the UK, even after Brexit. The UK is still committed to keeping our air clean, so these regulations remain in place.

Find your next compliant car with Cazoo

Whether you're chasing a Euro 6 diesel to dodge ULEZ charges, or simply want a clearer idea of what you're buying, it's worth checking a used car's Euro standard before you commit. Our guides to petrol vs diesel cars and should I buy a diesel car are worth a read if you're still deciding, and our car maintenance tips guide covers the other checks worth doing on any used car. When you're ready, you can browse our full range of used cars, including plenty of ULEZ-compliant used diesel cars.

Information correct as of August 2026. Euro 7 dates, Clean Air Zone charges and ULEZ pricing can all change, so check current guidance before you buy or travel.