If you drive into one of the UK’s major cities, you may enter a Clean Air Zone (CAZ). This is defined as an area, usually within an urban centre, where targeted action has been taken to improve air quality.
Clean Air Zones aim to address all sources of air pollution, including nitrogen dioxide and particulates, reducing the likelihood of pedestrians and other road users breathing them in.
Scotland does things differently with its own Low Emissions Zones, while London and Oxford also go their own ways with an Ultra Low Emissions Zone (ULEZ) and a Zero Emission Zone (ZEZ) respectively. Read on to discover what all these zones mean.
Let’s start by explaining the different categories of Clean Air Zones and how they could affect you – including the charges for driving into each city.
Non-charging Clean Air Zones
These are geographic areas, normally city centres, used as a focus for action to improve air quality. The are various measures open to the local authority, but charging a fee for entry into the CAZ isn’t one of them.
Charging Clean Air Zones
These are zones where motorists are required to pay a fee to enter or move within an area if they are driving an older vehicle that does not meet a particular ‘Euro’ exhaust emissions standard.
Classes of Clean Air Zones
There are four classes of Clean Air Zone: A, B, C and D. Each local authority can decide what level of restrictions to apply. However, note that Class D is the only CAZ to include cars.
The list below shows the vehicles and emissions standards that are relevant for each level of CAZ. The easiest way to determine your car’s Euro exhaust emissions category is to use the official GOV.UK vehicle tax and MOT checker tool.
Enter the car’s registration number and the information should be displayed next to ‘Euro status’.
- Class A: buses, coaches, taxis and private hire vehicles:
- Buses and coaches: Euro 6
- Taxis and private hire vehicles: Euro 6 (diesel) and Euro 4 (petrol)
- Class B: buses, coaches, taxis, priviate hire vehicles and HGVs:
- Buses, coaches and HGVs: Euro 6
- Taxis and private hire vehicles: Euro 6 (diesel) and Euro 4 (petrol)
- Class C: buses, coaches, taxis, private hire vehicles, HGVs and LGVs:
- Buses, coaches and HGVs: Euro 6
- Large vans, minibuses, LGVs, taxis and private hire vehicles: Euro 6 (diesel) and Euro 4 (petrol)
- Class D: buses, coaches, taxis, private hire vehicles, HGVs, LGVs and cars:
- Cars: Euro 4 (petrol), Euro 6 (diesel)
- Buses, coaches and HGVs: Euro 6
- Large vans, minibuses, LGVs, taxis and private hire vehicles: Euro 6 (diesel) and Euro 4 (petrol)
- Motorcycles and mopeds (optional): Euro 3
This is just an overview of the different classes. For a more in-depth description, read the UK Government’s framework.
Where are Clean Air Zones?
A number of cities were required by the UK Government to either reduce air pollution or carry out feasibility studies to determine whether or not a CAZ was required.
Here, we list all the schemes that are currently live at the time of writing (July 2026).
Bath
Bath has a Class C Clean Air Zone, meaning charges only apply to taxis, vans, buses, coaches and HGVs that do not meet the required standards. Depending on emissions, these fees can be up to £100. Drivers of private cars and motorcycle riders don’t have to pay, though, even if using their vehicle for work.
Birmingham
The Birmingham Clean Air Zone has been in operation since June 2021. It covers everywhere within the A4540 Middleway ring road – but not the Middleway itself.
Non-compliant cars, taxis and LGVs are subject to a daily charge of £8, rising to £50 per day for HGVs, coaches and buses. Failure to pay the charge results in a £120 fine, which is reduced to £60 if paid within 14 days.
The city initially worked with car supermarket Motorpoint to offer those who live or work within the CAZ a £2,000 scrappage discount to trade in their non-compliant vehicle. However, applications for this scheme have since closed
Bradford
Bradford maintains a Class C+ Clean Air Zone. It covers the area inside – and including – the Bradford outer ring road. It also extends out along the Aire Valley corridor to include Shipley and Saltare.
Private cars can drive in the city for free, but taxis and motorhomes face a £7 daily charge if they fail to Euro 6 diesel or Euro 4 petrol standards. Drivers of coaches and HGVs could pay up to £50 if they are deemed too polluting.
Bristol
The Bristol Clean Air Zone is the strictest Class D variety. Non-compliant cars (i.e. those below Euro 4 for petrol and Euro 6 for diesel), along with light goods vehicles and taxis, will be charged £9 to enter the city centre. The heaviest vehicles, such as buses and lorries, could face a daily fee of £100.
The CAZ covers a relatively small area of Bristol city centre, from the Avon gorge in the west to Temple Meads train station in the east.
Portsmouth
The Portsmouth Clean Air Zone launched on 29 November 2021. It is a Class B Zone, so the daily charges of £10 and £50 only apply to non-compliant taxis and HGVs respectively.
Sheffield
Sheffield’s Class C Clean Air Zone covers the city centre, including the A61 inner ring road. Private cars won’t be charged but taxi, bus and goods vehicle drivers should check if they face a fee. This ranges from £10 for cars to £50 for lorries.
Tyneside
Like Sheffield, Newcastle and Gateshead operate a Class C CAZ. The charge is £12.50 for non-compliant taxis or £50 for heavy vehicles.
There are many car parks around the edge of the Clean Air Zone if you prefer to leave your vehicle and take public transport.
Other Low Emission Zones in the UK
London’s Ultra Low Emission Zone (ULEZ) came into force in April 2019. It stretches across all boroughs in the capital, but excludes the M25 orbital motorway. Non-compliant vehicles are currently charged £12.50 for entry into the city. For more information, read our separate London ULEZ guide.
Oxford’s Zero Emissions Zone only covers nine streets in the historic city centre, but its criteria are more complicated. Electric car drivers can enter the area for free, those emitting up to 75g/km of CO2 must pay £2, while vehicles that meet the typical Euro 4 (petrol) and Euro 6 (diesel) standards are liable for a £4 charge.
Those in older, more polluting cars have to pay £10 to drive into Oxford. Automatic number plate recognition (ANPR) cameras are used to enforce the zone.
Scotland has a different system of Low Emission Zones. Put simply, unless your car is electric, or it meets the Euro 4 (petrol) and Euro 6 (diesel) standards, you are not allowed to drive into certain city centres. Doing so will earn you a fine of £60, which is reduced to £30 if paid within 14 days.
The Scottish cities with Low Emission Zones are Aberdeen, Dundee, Edinburgh and Glasgow. These operate 24 hours a day and 365 days a year. The main exemptions are for disabled Blue Badge holders and classic cars that are deemed ‘of historic interest to the United Kingdom’.
Will Clean Air Zones become the norm?
With the government under pressure to improve air quality, other towns and cities are expected to introduce Clean Air Zones or their own interpretations of the schemes.
Dirty air is linked to 40,000 early deaths every year in the UK, and 70 percent of people want the government to take some form of action. In the future, paying a fee to enter an urban area might become the norm rather than the exception.
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