ULEZ, CAZ and Low Emission Zones: What UK Drivers Need to Know

What Are Low Emission Zones?

Low emission zones are designated areas in UK cities where vehicles that do not meet certain exhaust emission standards face daily charges or restrictions. Their purpose is to reduce harmful air pollution — particularly nitrogen dioxide (NO₂) and particulate matter (PM) — which contribute to respiratory illness, cardiovascular disease, and thousands of premature deaths in the UK each year.

These zones target the most polluting vehicles and incentivise drivers to switch to cleaner alternatives. They have become an increasingly significant factor in the cost of running a car, particularly for owners of older diesel vehicles.

Purpose of ULEZ and CAZ Schemes

The key aims of emission zones are:

• Improve urban air quality — reducing concentrations of NO₂ and PM to within legal limits
• Protect public health — air pollution contributes to an estimated 28,000 to 36,000 early deaths per year in the UK
• Accelerate the shift to cleaner vehicles — by making it financially disadvantageous to drive the most polluting cars
• Meet legal obligations — the UK government has been ordered by courts to meet EU-derived air quality standards in the shortest possible time

The zones do not ban non-compliant vehicles outright. Instead, they impose a daily charge for entering or driving within the zone. The charge is intended to discourage use rather than prohibit it entirely.

Key Types of Emission Zones

ULEZ (Ultra Low Emission Zone)

The Ultra Low Emission Zone is London-specific and is operated by Transport for London (TfL). Originally introduced in central London in April 2019, it was expanded to the North and South Circular roads in October 2021 and then to all London boroughs in August 2023.

Key facts:

• Operating hours — 24 hours a day, 7 days a week, 365 days a year (including weekends and bank holidays)
• Daily charge — £12.50 for non-compliant cars, motorcycles, and vans; £100 for lorries, buses, and coaches
• Penalty for non-payment — £180 (reduced to £90 if paid within 14 days)
• Who pays — vehicles that do not meet the required emission standards
• Who is exempt — vehicles that meet the standards, registered disabled tax class vehicles, military vehicles, and certain historic vehicles

ULEZ is enforced by Automatic Number Plate Recognition (ANPR) cameras positioned throughout the zone. Your vehicle's registration is checked against the TfL database automatically. If your car is non-compliant and you drive within the zone, the charge applies — whether you are a London resident or a visitor.

CAZ (Clean Air Zone)

Clean Air Zones operate in cities outside London and are managed by local councils rather than TfL. Each city sets its own rules, charges, and boundaries.

CAZ zones are classified into four categories:

Class	Vehicles charged
A	Buses, coaches, and taxis only
B	Buses, coaches, taxis, and heavy goods vehicles (HGVs)
C	Buses, coaches, taxis, HGVs, and light goods vehicles (vans)
D	Buses, coaches, taxis, HGVs, vans, and private cars

Only Class D zones charge private cars. As of 2026, the following cities have active Clean Air Zones that affect private car drivers:

• Birmingham — Class D; non-compliant private cars charged £8 per day
• Bristol — Class D (small central zone); non-compliant private cars charged £9 per day
• Bradford — Class C (HGVs, buses, taxis, and vans only; private cars not charged)
• Bath — Class C (private cars not charged)
• Portsmouth — Class B (private cars not charged)
• Sheffield — Class C (private cars not charged)
• Newcastle / Gateshead — Class C (private cars not charged)

More cities are considering or planning Clean Air Zones. The status of these zones changes periodically, so always check the latest position before travelling.

LEZ (Low Emission Zone)

The London Low Emission Zone is a separate, older scheme from ULEZ. It covers most of Greater London but only applies to larger vehicles — lorries, buses, coaches, and heavier vans (over 3.5 tonnes). Private cars are not affected by the LEZ.

The LEZ charges are significantly higher than ULEZ: £100 per day for vehicles that do not meet the required standards, with a penalty of £1,000 for non-payment.

For private car drivers, the LEZ is not relevant. The ULEZ is the scheme that matters.

Cities with Active Zones in the UK

Here is a summary of the zones that affect private car drivers as of early 2026:

City	Zone type	Private cars charged?	Daily charge
London (all boroughs)	ULEZ	Yes	£12.50
Birmingham	CAZ Class D	Yes	£8.00
Bristol (central zone)	CAZ Class D	Yes	£9.00
Bath	CAZ Class C	No	—
Bradford	CAZ Class C	No	—
Sheffield	CAZ Class C	No	—
Portsmouth	CAZ Class B	No	—
Newcastle / Gateshead	CAZ Class C	No	—

If you do not drive in London, Birmingham, or central Bristol, your private car is currently unaffected by emission zone charges. However, other cities may introduce Class D zones in the future.

Vehicles Affected by Emission Zones

Emission zones use Euro emission standards to determine which vehicles are compliant:

Euro Standards Explained

Euro standards set limits on the pollutants a vehicle can produce. Each new standard tightens the limits. The key standards for emission zone compliance are:

Standard	Approximate years	Applies to
Euro 3	2000–2006 (petrol), 2000–2006 (diesel)	Older vehicles
Euro 4	2006–2011 (petrol), 2006–2011 (diesel)	ULEZ petrol threshold
Euro 5	2011–2015 (petrol), 2011–2015 (diesel)	—
Euro 6	2015 onwards (petrol and diesel)	ULEZ diesel threshold

The dates above are approximate. Some vehicles meet later Euro standards earlier than the typical dates, and some later vehicles were still manufactured to earlier standards. The exact Euro standard your car meets is determined by its type approval, not simply its registration year.

Petrol vs Diesel Compliance Rules

The compliance requirements differ significantly between petrol and diesel:

Petrol cars:

• Must meet Euro 4 or later
• In practice, this means most petrol cars registered from approximately 2006 onwards are compliant
• Many petrol cars from 2005 also meet Euro 4
• Petrol cars registered from 2001 to 2005 may or may not comply — it depends on the specific model and engine

Diesel cars:

• Must meet Euro 6 or later
• In practice, this means most diesel cars registered from approximately September 2015 onwards are compliant
• Some diesel cars registered from 2014 meet Euro 6 if the manufacturer adopted the standard early
• Diesel cars registered before 2015 are almost certainly non-compliant

This difference means diesel cars face much stricter requirements. A 2010 diesel car that runs perfectly well is non-compliant for ULEZ purposes, while a 2010 petrol car of similar age is usually fine. This is because diesel engines produce significantly more NOₓ, which is the primary pollutant these zones target.

Electric and Hybrid Vehicles

• Pure electric vehicles — always compliant; zero exhaust emissions
• Plug-in hybrids — compliant if they meet Euro 4 (petrol engine) or Euro 6 (diesel engine), which virtually all modern PHEVs do
• Self-charging hybrids — same rules as their engine type (usually petrol, so Euro 4 or later)

Daily Charges Explained

How Charges Work

• Charges apply per day, not per trip. Whether you drive through the zone once or ten times in a day, you pay one daily charge.
• The "day" runs from midnight to midnight for ULEZ and varies by city for CAZ zones.
• Payment must be made by midnight on the third day after driving in the ULEZ. For CAZ zones, check the specific city's rules.
• Payment is made online, by phone, or via the TfL app (for ULEZ) or the specific city's CAZ portal.

Auto Pay

For London's ULEZ, you can register for Auto Pay through TfL, which automatically charges the daily fee to your payment card whenever your vehicle is detected in the zone. This prevents accidental non-payment and the associated penalties.

Cost Over Time

For regular commuters, daily charges add up rapidly:

Frequency	ULEZ (£12.50/day)	Birmingham CAZ (£8/day)
5 days per week	£62.50/week — £3,250/year	£40/week — £2,080/year
3 days per week	£37.50/week — £1,950/year	£24/week — £1,248/year
1 day per week	£12.50/week — £650/year	£8/week — £416/year
Occasional (2x/month)	£300/year	£192/year

At these rates, the cost of a non-compliant car becomes very significant very quickly. For a five-day-a-week London commuter, ULEZ charges alone exceed the cost of many other running expenses combined.

How to Check If a Car Is Compliant

TfL Vehicle Checker (ULEZ)

Transport for London provides a free online tool at tfl.gov.uk/modes/driving/check-your-vehicle. Enter the vehicle registration number and it will tell you whether the vehicle meets ULEZ standards, the daily charge (if any), and the vehicle's emission standard.

Clean Air Zone Vehicle Checker (CAZ)

For cities outside London, the government provides a centralised checker at gov.uk/clean-air-zones. This tool lets you check whether your vehicle is compliant for any UK Clean Air Zone, see which zones affect your vehicle, and identify the charges that would apply.

Before Buying a Used Car

If you live in or regularly travel through an emission zone, always check compliance before buying. A seemingly bargain-priced diesel car becomes far less attractive when it costs an additional £3,000+ per year in emission charges.

Options If Your Car Is Not Compliant

If your vehicle does not meet the emission standards, you have several options:

Pay the Daily Charge

The simplest option if you enter a zone infrequently. For occasional visits, paying £12.50 or £8 per day may be cheaper than the alternatives.

Best for: Drivers who enter emission zones fewer than 2–3 times per month.

Upgrade the Car

Replacing your non-compliant vehicle with one that meets the standards eliminates the charges entirely.

• Compliant petrol cars can be found from as little as £2,000–£3,000 on the used market (2006+ models)
• Compliant diesel cars start from around £5,000–£7,000 (2015+ models)
• Electric vehicles are always compliant and are dropping in price on the used market
• Scrappage schemes — some zones offer financial support to help owners of non-compliant vehicles upgrade

Best for: Regular zone users, especially commuters. The cost of upgrading often pays for itself within 1–2 years through avoided charges.

Use Alternative Transport

For specific journeys into emission zones, consider public transport, cycling or e-bikes, car sharing or hire, or park and ride schemes.

Best for: Drivers who only occasionally need to travel into emission zones and have practical alternatives.

How Emission Zones Affect Resale Value

Emission zones have created a two-tier used car market:

Compliant Vehicles

Cars that meet ULEZ and CAZ standards are worth more because buyers know they can drive anywhere without charges. This is particularly true in London and the South East, where ULEZ compliance is a significant selling point.

Non-Compliant Vehicles

Non-compliant cars — especially older diesels — have lost value disproportionately. A pre-2015 diesel that would have been worth £5,000 may only fetch £3,000–£4,000 because potential buyers factor in the emission zone limitations.

This effect is strongest in London and surrounding areas, cities with Class D CAZ zones (Birmingham, Bristol), and areas where new zones are planned or expected.

Buying Advice

When buying a used car:

• Always check ULEZ/CAZ compliance — even if you do not currently drive in a zone, you may need to in the future, and it affects resale value
• Diesel pre-2015 carries significant risk — emission zones may expand, and the compliance gap makes these vehicles harder to sell
• Petrol post-2006 is generally safe — Euro 4 compliance covers all current and planned UK emission zones
• Electric and newer hybrids are future-proof — zero-emission vehicles will remain compliant regardless of how standards tighten

Running a full vehicle check before buying helps you verify the car's emission standard and ensures there are no other hidden issues such as outstanding finance, write-off history, or mileage discrepancies.