ULEZ and clean air zones explained

Four different things with similar names

The word zone is doing too much work in British motoring. There are four separate mechanisms in use, and knowing which one you are driving into tells you whether you are looking at a daily charge, an outright ban or a charge that has nothing to do with emissions.

A charging zone lets a non compliant vehicle in and bills it for the day, which is how London's Ultra Low Emission Zone and the English Clean Air Zones work. A prohibition zone does not let a non compliant vehicle in at all, which is how the Scottish Low Emission Zones work, and there is no way to pay your way through one. A congestion scheme charges for road space rather than for emissions. A zero emission zone charges everything except a zero emission vehicle, which is the model Oxford is piloting on a small number of city centre streets.

Charges are also per calendar day rather than per journey in the charging zones, so two trips in and out on the same day cost one charge, while a trip that crosses midnight costs two. That single detail is worth more to a delivery driver than any amount of general reading.

• London ULEZ: charging zone, £12.50 a day for a non compliant car, van or motorcycle.
• English Clean Air Zones: charging zones, class A to D, only class D can charge cars.
• Scottish LEZs: prohibition, no charge available, penalty from the first capture.
• London Congestion Charge: road space charge, nothing to do with emissions.

How the standards actually work

Nearly every scheme in the country uses the same Euro emissions standards as its test. GOV.UK sets out the minimum standards for the English zones: Euro 6 for a diesel and Euro 4 for a petrol car, van, minibus, taxi or private hire vehicle, Euro 3 for a motorcycle, and Euro VI for a bus, coach or heavy goods vehicle. London's ULEZ uses the same standards for cars, vans and minibuses, and Scotland's LEZs use Euro 4 for petrol and Euro 6 for diesel cars and vans.

The standard is about what the vehicle was certified to when it was built, not about how old it looks or how well it runs. Age is only a rough guide, and the gap between the earliest compliant examples and the last non compliant ones is wide enough that guessing from the registration year is unreliable. Check the vehicle rather than the year: DVLA holds the emissions data, and both GOV.UK's clean air zone checker and TfL's own checker will give you a straight answer from the number plate.

Two details save arguments. A plug in hybrid is judged on its petrol or diesel engine, not on its battery, so an old hybrid can be non compliant while a newer diesel is fine. And a fully electric vehicle meets every standard in every zone, which does not make it exempt from the Congestion Charge, because that scheme is not about emissions at all.

London: three schemes on the same roads

The Ultra Low Emission Zone charges £12.50 a day for a non compliant car, motorcycle, van or specialist vehicle up to 3.5 tonnes and minibuses up to 5 tonnes. It runs 24 hours a day, every day of the year except Christmas Day, and it covers all London boroughs, though not the M25 itself. There is no weekday exception and no overnight let off, which is the difference between it and the Congestion Charge that most drivers assume applies.

The Low Emission Zone is a separate, older scheme aimed at the heaviest diesel vehicles, and it never applied to cars or motorcycles at all. Its penalties are on a different scale from anything else in London: £500 for a non compliant vehicle between 1.205 and 3.5 tonnes, reduced to £250 if you pay within 14 days, £1,000 reduced to £500 for a vehicle over 3.5 tonnes that meets Euro IV but not Euro VI, and £2,000 reduced to £1,000 for one that does not even reach Euro IV.

The Congestion Charge is the one that is not about emissions. It is £18 a day if you pay on the day or in advance, or £21 if you pay by midnight on the third day after travelling, and it applies from 07:00 to 18:00 Monday to Friday and from 12:00 to 18:00 at weekends and on bank holidays. A brand new petrol car pays it in full. Miss it and the penalty is £180, halved to £90 if you pay within 14 days, and it rises by half again to £270 if it is still unpaid after 28 days.

English Clean Air Zones and the four classes

Outside London, England's charging zones are built from a national framework with four classes, and the class tells you which vehicles are in scope. Class A covers buses, coaches, taxis and private hire vehicles. Class B adds heavy goods vehicles. Class C adds vans and minibuses. Class D adds cars, and the local authority has the option to include motorcycles as well.

That means the single most useful question about any English zone is which class it is. In a class B or class C zone, a private car is never charged no matter how old it is. Only a class D zone can charge you for driving your own car, and only some of them extend that to motorcycles. Bath, Bradford, Portsmouth, Sheffield and Tyneside run zones that leave private cars alone. Birmingham and Bristol are class D, so an old car does pay there.

The charges themselves are set locally rather than nationally, and so are the penalties, the exemptions and the local discount schemes for residents and workers. That is why two class C zones can charge different amounts for the same van. GOV.UK's clean air zone service is the place to check a specific plate against a specific city, and each zone page on this site carries the charges, the standards, the exemptions and the boundary for that zone.

Scotland does not let you pay

Glasgow, Edinburgh, Aberdeen and Dundee run Low Emission Zones, and they are not charging schemes. There is no daily rate to pay and no way to buy your way in. If a vehicle does not meet the standard it is not allowed into the zone, and the first time a camera records it there you get a penalty charge.

The penalties escalate in a way no English scheme does. The first charge is £60, reduced to £30 if you pay within 14 days. It then doubles for each further contravention by the same vehicle in the same zone within 90 days, capped at £480 for a car or light goods vehicle and £960 for a minibus, bus, coach or heavy goods vehicle. Once 90 days pass with no contravention the amount resets to £60. Four unlucky trips in a fortnight is therefore a great deal more expensive than the arithmetic most drivers do in their heads.

The standards are the familiar ones, Euro 4 for petrol and Euro 6 for diesel cars and vans, and the exemptions are set nationally rather than city by city. Blue Badge holders, emergency vehicles, military vehicles and historic vehicles over 30 years old are outside the rules, and councils can grant time limited exemptions for specialist vehicles.

Checking before you drive

Two free checkers cover the country between them. GOV.UK's clean air zone service checks a plate against the English zones and lets you pay the daily charge, and it cannot check vehicles registered outside the UK. TfL runs its own checker for the ULEZ, LEZ and Congestion Charge. Scotland publishes a vehicle checker for the LEZs. Doing it once for your own car is a five minute job that settles the question for years, because a vehicle's Euro standard never changes.

If you are buying a car, do the check before you buy rather than after. An otherwise sensible diesel that fails the Euro 6 test is a car you will pay £12.50 a day to use in London and cannot take into Glasgow at all, and that shows up in what it will be worth when you come to sell it.

One habit saves money over time. When you pay a charge for a vehicle that is not yours, whether a hire car or a relative's, use the number plate on the vehicle rather than the one on the booking, and keep the confirmation. Camera enforcement matches the plate, and a payment against the wrong plate is a penalty waiting to arrive.