ULEZ-Friendly Cars
ULEZ (Ultra Low Emission Zone) compliance affects whether you pay a daily charge to drive in London's ULEZ and similar clean air zones in other UK cities. It's worth understanding clearly before you buy, especially if you regularly drive into an affected area.
What 'ULEZ compliant' actually means
Petrol cars generally need to meet the Euro 4 emissions standard, which covers the vast majority of petrol cars first registered from 2006 onwards.
Diesel cars need to meet the stricter Euro 6 standard, which generally means registered from around September 2015 onwards — this catches out many otherwise perfectly good used diesels.
Fully electric and most hybrid cars comply automatically, since the standard is based on tailpipe emissions.
How to check before you buy
Transport for London provides a free vehicle checker where you enter a registration number to confirm ULEZ compliance for London specifically — worth using before committing to a car if this matters to you.
Other UK cities (including Birmingham, Bristol, and others) run their own clean air zones with broadly similar Euro 4/Euro 6 rules, though it's worth checking the specific scheme for the city you'll be driving in.
If a used car's exact registration date is close to the Euro 6 cutoff for diesel, ask the seller to confirm the Euro standard listed on the V5C or check via the vehicle's registration.
What it costs if a car isn't compliant
Non-compliant cars are charged a daily fee to drive within the relevant zone (£12.50 per day in London's ULEZ at the time of writing) — worth factoring into running costs if you'll be driving into the zone regularly.
Whatever you're looking at, it's worth reading our guide on what to check before buying a used car before you view anything in person.