Short answer: before you buy a used car you plan to drive in London, check its number plate on TfL’s official vehicle checker. If you will drive in an English city with a Clean Air Zone, also use the GOV.UK Clean Air Zone checker. Both are free and run by the authorities that set the charges. Do this before you pay a deposit, not after.
Last reviewed: 22 October 2026. Rules, zones and charges are set by Transport for London (TfL) and local councils and can change. Always confirm with the official checker for the exact car you are buying.
What ULEZ is and where it applies
The Ultra Low Emission Zone (ULEZ) is run by TfL. According to TfL, it:
- operates 24 hours a day, 7 days a week, every day of the year except Christmas Day (25 December)
- covers all London boroughs, but does not include the M25
- applies to cars, motorcycles, vans and specialist vehicles up to and including 3.5 tonnes, and minibuses up to and including 5 tonnes
If a vehicle does not meet the ULEZ emissions standards and is not exempt, the driver has to pay a daily charge to drive within the zone. TfL publishes the current charge and penalty amounts on its ULEZ page. We don’t repeat them here because they can change.
Other Clean Air Zones in England
Outside London, some councils run Clean Air Zones (CAZs). GOV.UK lists zones in Bath, Birmingham, Bradford, Bristol, Portsmouth, Sheffield and Tyneside (Newcastle and Gateshead).
Not every zone charges private cars. GOV.UK sorts zones into four classes, and only Class D zones include cars. In the GOV.UK list, Birmingham and Bristol are Class D. Bath, Bradford, Sheffield and Tyneside are Class C, and Portsmouth is Class B. Those zones cover vehicles such as buses, taxis, lorries and, for Class C, vans and minibuses, but not private cars. Councils can change their schemes, so check the zone you will actually drive in.
GOV.UK says Clean Air Zones operate 24 hours a day, 7 days a week. Scotland has separate low emission zones with their own rules. See Low Emission Zones Scotland.
How to check a vehicle
- Get the registration number from the seller before you travel to a viewing.
- For London: enter it in TfL’s Check your vehicle tool. TfL says the tool checks ULEZ, the Low Emission Zone, the Congestion Charge and other London charges. It also says that results are based only on the emissions standard and type of vehicle, so discounts and exemptions linked to you as the driver are not included.
- For English Clean Air Zones: use GOV.UK’s Drive in a clean air zone service. GOV.UK notes it cannot check vehicles registered outside the UK.
- Check the details match the car. Use the free DVLA vehicle enquiry service to confirm the make, colour, fuel type and date of first registration match the advert and the car in front of you. A checker result only means something if it is for the right car.
What makes a car ULEZ compliant
ULEZ compliance depends on the car’s official Euro emissions standard. For cars, TfL’s minimum standards (checked 22 October 2026) are:
| Fuel | TfL minimum standard for cars |
|---|---|
| Petrol | Euro 4 (NOx) |
| Diesel | Euro 6 (NOx and PM) |
TfL says ULEZ is enforced on the car’s declared emissions, not its age. As a general guide, TfL says that:
- petrol cars that meet the standards are generally those first registered as new with DVLA after 2005, although cars meeting the standard have been available since 2001
- diesel cars that meet the standards are generally those first registered as new after September 2015
Those dates are a rule of thumb, not a guarantee. A car near either cut-off could go either way, so use the checker.
The GOV.UK guidance gives the same minimum standard for cars in Clean Air Zones: Euro 6 for diesel and Euro 4 for petrol.
Is ULEZ the same as the congestion charge?
No. They are separate TfL schemes:
- ULEZ is about emissions. It covers all London boroughs and runs all day, every day except Christmas Day.
- The Congestion Charge is about traffic in central London. It applies in a smaller central zone at set times. See TfL’s Congestion Charge page for the current hours and charge.
A car that meets the ULEZ standards can still have to pay the Congestion Charge. TfL says ULEZ charges are in addition to any Congestion Charge that applies.
Before buying: questions and paperwork
- Look at the V5C (log book). TfL says the Euro emissions standard may be listed on the V5C. If it isn’t, TfL suggests using the date the car was first registered (section B of the V5C) and checking GOV.UK’s vehicle enquiry service.
- Ask whether the car has been modified. Changes such as an engine swap or fuel conversion must be recorded on the V5C. Make sure the record matches the car.
- Run the official checker yourself. Don’t rely on a screenshot or an “ULEZ compliant” line in the advert.
- Think about where you will drive. Check the London zones and any Clean Air Zone on your regular routes.
- Do the usual used-car checks too. ULEZ is one detail among many. Our used car buying checklist covers the rest, and our guides to the vehicle registration check and free official checks explain the GOV.UK services.
Frequently asked questions
Is ULEZ 24/7?
Yes. TfL says ULEZ operates 24 hours a day, 7 days a week, every day of the year except Christmas Day.
Is ULEZ the same as the congestion charge?
No. ULEZ is an emissions scheme covering all London boroughs. The Congestion Charge is a separate charge for driving in central London at set times. A car can be liable for one, both or neither.
How do I know if my car is ULEZ compliant?
Enter the registration number in TfL’s official vehicle checker. The V5C may also show the car’s Euro emissions standard.
Do petrol cars from a given year pass?
TfL says petrol cars that meet the standards are generally those first registered as new after 2005, and diesels generally after September 2015. Compliance is based on the car’s declared emissions rather than its age, so always check the specific car.
Do I need to check Clean Air Zones if I don’t drive in London?
Only if you drive in a zone that charges cars. Check the GOV.UK service for the cities you visit, and Low Emission Zones Scotland if you drive in Scottish cities.
Sources checked 22 October 2026: Transport for London, Ultra Low Emission Zone, ULEZ standards for cars, Check your vehicle and Congestion Charge; GOV.UK, Clean Air Zones and Drive in a clean air zone; GOV.UK, Change vehicle details on a V5C.