The UK’s Clean Air Zones Explained


The United Kingdom is on a seemingly unending quest to ensure that the air its citizens breathe is as clean as possible. From London to Edinburgh, cities and towns across the country are taking steps to reduce air pollution, which is linked to respiratory illnesses such as asthma, bronchitis, and even lung cancer. One of the most recent measures put in place is the creation of clean air zones. 

What Is a Clean Air Zone?

Clean air zones are designated areas within an urban environment where vehicles are subject to strict emissions standards. The government sets these standards and requires vehicles to meet certain emissions levels to be allowed within the zone. These zones aim to improve air quality in areas with high pollution levels and lessen the effect of diesel emissions on the environment.

How Do They Work?

Clean Air Zones work by imposing charges on high-polluting vehicles entering the designated area. The aim is to discourage such polluting vehicles, decrease air pollution, and ultimately improve public health. Drivers of older, heavily polluting diesel vehicles with higher levels of nitrogen oxide (NOx) and particulate matter (PM) will be most affected. To get more information on diesel emissions, go to

The effectiveness of Clean Air Zones is also subject to debate. Some critics argue that Clean Air Zones are ineffective enough to significantly reduce air pollution, while others argue that they unfairly target drivers of older diesel vehicles.

Clean Air Zone Categories

There are two main types of clean air zones:

  • Non-Charging Clean Air Zones

Non-charging clean air zones work by encouraging the use of low-emission vehicles. They impose restrictions on higher-emitting vehicles, such as taxis and buses.

  • Charging Clean Air Zones

Charging clean air zones, on the other hand, requires vehicles to pay a fee before entering the zone. This fee is known as a Clean Air Zone charge. This zone type aims to reduce the number of high-emitting vehicles on the road. The charges apply to all vehicle types, including cars, buses, and HGVs. However, various exemptions and discounts are available, depending on the vehicle and its emissions standards.

Classes of Clean Air Zones

The Clean Air Zones (CAZ) are classified into four categories: A, B, C, and D. Each class includes different types of vehicles exempted, but all classes adhere to the emissions standards set by the London Ultra Low Emission Zone (ULEZ). 

The classification of a CAZ is determined by the local authority responsible for its implementation. At the same time, the UK government established the regulations governing these zones through the national Clean Air Zone framework introduced in February 2020.

Which Cities Have Clean Air Zones in the UK?

London is home to its own Ultra Low Emission Zone (ULEZ), which stands apart from the Clean Air Zone legislation. However, similar initiatives have been planned for other cities in the UK.

  • Bath

The Bath Clean Air Zone was implemented on March 15, 2021. This zone, categorised as class C, does not charge private cars and motorbikes for entry. However, buses, coaches, minibuses, light goods vehicles, and trucks are subject to a fee.

  • Birmingham

The Birmingham Clean Air Zone was launched on June 1, 2021. Classified as class D, non-compliant vehicles are charged a fee ranging from £8 to £50. Electric and hybrid cars, as well as motorcycles, are exempt from charges. However, the petrol or diesel engines in hybrid vehicles must meet specific criteria.

  • Bristol

The Bristol Clean Air Zone was implemented on November 28, 2022. This class D zone will charge £9 to £100 on all high-emission vehicles, including private cars, to drive through the city centre.

  • Manchester

A comprehensive evaluation is currently being conducted on the Greater Manchester Clean Air Zone. Initial plans involved charging private hire vehicles, vans, buses, and HGVs for entry. However, a lack of compliant vehicles and the increase in living costs has led to its postponement. 

  • Portsmouth

The Portsmouth Clean Air Zone was launched on November 29, 2021. This class B zone exempts private cars, motorcycles, and vans from charges. However, non-compliant taxis, private hire vehicles, HGVs, buses, and coaches incur daily fees.

  • Southampton

Classified as B, Southampton has a non-charging CAZ.

Consequences of Non-Compliance with CAZ Regulations

Non-compliance with clean air zone regulations can result in a fine. These fines can be significant, ranging from small, fixed penalties to larger fines for repeated non-compliance. In addition to fines, vehicles that fail to meet the requirements of clean air zones can also be banned from entering the zone altogether.

It is hoped that CAZs will significantly impact air quality, benefiting those who live and work in those areas and the wider environment. In addition to improving public health, reducing air pollution can help mitigate climate change, making Clean Air Zones a crucial part of any long-term strategy to protect the planet.