ULEZ & Clean Air Zone Checker
Diesel cars registered from 2015 are generally Euro 6, which meets ULEZ standards.
ULEZ rules in plain English
London’s Ultra Low Emission Zone covers all 32 boroughs — effectively everything inside the M25 — and operates 24 hours a day, every day except Christmas Day. To drive in without paying, a petrol car must meet Euro 4 emissions standards (generally cars registered from 2006 onwards) and a diesel must meet Euro 6 (generally registered from September 2015 onwards). Electric and hydrogen vehicles are always compliant.
Anything else pays £12.50 a day — and ignore it and the penalty is £180 (reduced to £90 if paid within 14 days). Note this sits on top of the £15 Congestion Charge if you enter central London.
Other UK clean air zones
London isn’t alone. Birmingham, Bath and Bristol run Class D clean air zones with similar emission thresholds (Euro 4 petrol, Euro 6 diesel) but their own daily charges and exemptions. Other cities have zones targeting buses, taxis and lorries rather than private cars. Rules differ by city, so check the GOV.UK clean air zone checker for the specific place you’re driving.