A clean air zone is an area where the most polluting vehicles are charged or restricted to improve air quality. Operating in several English cities, it targets older, higher-emission vehicles that fail set Euro emissions standards.
In one line: A clean air zone charges or restricts the most polluting vehicles entering certain UK city areas to cut emissions.
How a clean air zone works
Clean air zones are established by local authorities under the Environment Act 1995 framework and apply in cities such as Birmingham, Bristol and Bath. Charges depend on the zone class and the vehicle's emissions rating.
Compliant vehicles, typically petrol cars meeting Euro 4 and diesels meeting Euro 6, pay nothing. A non-compliant car entering a charging zone might pay around 9 GBP per day, so a week of daily trips could cost roughly 63 GBP before any penalty for non-payment.
Some zones charge only buses, taxis and lorries, while others include private cars, so the rules vary sharply between cities.
Clean air zone vs the ULEZ
A clean air zone is the general scheme used across several English cities, while the ULEZ is London's specific version with its own boundary and daily charge. Both penalise older vehicles, but rates, classes and exemptions differ by location.
Emissions standards, not a vehicle's age alone, decide whether a charge applies, so a well-specified older diesel can still be compliant.
Primary source: GOV.UK: Clean air zones