A car is ULEZ compliant if it meets specific Euro emissions standards for its fuel type (mainly Euro 4 for petrol and Euro 6 for diesel), which means it produces low enough NOx and particulate emissions to avoid the daily ULEZ charge in London.

Core ULEZ rules

  • Petrol cars must meet at least Euro 4 emissions standards, which most cars registered from about January 2006 onwards do.
  • Diesel cars must meet Euro 6 standards, typically applying to cars registered from about September 2015 onwards.
  • Electric cars are always treated as ULEZ compliant because they have zero tailpipe emissions.

What “ULEZ compliant” means technically

  • ULEZ standards are built on the European “Euro” emissions rules, which limit pollutants like nitrogen oxides (NOx), carbon monoxide (CO), hydrocarbons, and particulate matter (PM).
  • For London ULEZ, the practical test is whether the car’s official type‑approval data shows it at or above the required Euro standard (Euro 4 petrol, Euro 6 diesel) so it falls below the set NOx and PM limits.

How to check if your car is compliant

  • You can use official or reputable online checkers by entering your registration number; these services query DVLA‑linked databases and confirm whether your vehicle is classified as compliant for ULEZ charging.
  • On the V5C log book, some newer vehicles list the Euro standard in section D.2, which can help you confirm compliance without using an online tool.

Other vehicle types and exemptions

  • For vans and minibuses , petrol models generally need Euro 4 and diesel models Euro 6 to be ULEZ compliant, similar to cars.
  • Certain vehicles with a historic vehicle tax class or specific disabled tax classes can be exempt from ULEZ charges even if they do not meet the usual Euro standard thresholds.

Practical tips if your car isn’t compliant

  • Consider:
    • Switching to a compliant used petrol Euro 4+ or diesel Euro 6 car.
    • Moving to a hybrid or fully electric model to avoid charges and future restrictions.
  • Some areas and times have offered scrappage or upgrade schemes to help owners replace non‑compliant cars, so checking current local schemes can reduce the cost of changing vehicle.

Information gathered from public forums or data available on the internet and portrayed here.