Road tax in the UK is officially called Vehicle Excise Duty, or VED. Almost every vehicle used or kept on a public road must be taxed, and the amount you pay depends on a surprising number of factors — chiefly your car's CO₂ emissions and, critically, the date it was first registered.
The reason car tax feels so confusing is that there are effectively three different systems running in parallel, depending on how old your car is. Understanding which one applies to your vehicle is the key to making sense of it all.
The three road tax systems
Cars registered before 1 March 2001
The oldest system is the simplest. Vehicles registered before March 2001 are taxed purely on engine size, with just two bands: one rate for engines up to 1549cc, and a higher rate for engines above 1549cc. CO₂ emissions don't come into it at all.
Cars registered between March 2001 and March 2017
This is where CO₂ emissions entered the picture. Cars in this window are taxed according to 13 CO₂ bands, labelled A to M. The cleaner the car, the lower the band and the cheaper the tax. Band A cars (the very lowest emitters) historically paid nothing, while the highest-emitting Band M cars pay several hundred pounds a year.
This system rewards low-emission vehicles heavily, which is why a small, efficient car from this era can be remarkably cheap to tax — sometimes just £20 to £35 a year.
Cars registered on or after 1 April 2017
The system changed significantly in April 2017. For cars registered after this date:
- There's a first-year rate based on CO₂ emissions, often much higher, paid only in the first year
- After that, most cars move to a flat standard rate regardless of emissions
- Cars with a list price over £40,000 pay an additional premium for five years
This change means the relationship between emissions and tax is now weaker after the first year — a clean and a dirty petrol car registered after 2017 often pay the same standard rate annually.
Why your registration date matters so much: Two seemingly identical cars — same model, same emissions — can have completely different tax costs purely because one was registered in March 2017 and the other in April 2017. Always check the actual registration date.
How CO₂ emissions affect your tax
For the millions of cars on UK roads registered between 2001 and 2017, CO₂ emissions are the single biggest factor in what you pay. The bands work on a sliding scale — every step up in emissions moves you into a more expensive band.
This is why knowing your car's exact CO₂ figure matters. It's printed on your V5C logbook, but it's also held on the official DVLA record — which means you can look it up instantly from the number plate alone.
CHECK YOUR ROAD TAX COST
Enter your reg to see your exact CO₂ band and annual road tax — calculated from official DVLA data.
Check a Vehicle →Electric and low-emission vehicles
For years, fully electric vehicles paid zero road tax — one of the major incentives to go electric. However, this is changing. From April 2025, electric vehicles became subject to VED for the first time, though rates remain relatively modest compared to high-emission petrol and diesel cars. If you're buying an EV, it's worth checking the current rate rather than assuming it's still free.
How to avoid overpaying
Road tax isn't something you can negotiate, but there are still ways to avoid paying more than you need to:
- Check the cost before you buy. Tax can vary from £20 to over £700 a year depending on the car. Factor it into your budget before committing.
- Don't pay by monthly direct debit if you can avoid it. Paying annually in one go is cheaper than spreading it — monthly and six-monthly payments carry a surcharge.
- Declare SORN if the car is off the road. If you're not using a vehicle and keeping it on private land, a Statutory Off Road Notification means you don't pay tax at all.
- Remember tax no longer transfers with the car. Since 2014, when you buy a used car the seller's tax is cancelled — you must tax it yourself before driving away.
Important: Road tax does not transfer when you buy a used car. The moment you become the registered keeper you are responsible for taxing it — driving an untaxed car, even one you've just bought, is an offence.
Checking road tax status and cost
You can check whether any vehicle is currently taxed, when the tax is due, and what it should cost — all from the number plate. carDNA pulls this directly from official DVLA records and calculates the annual cost based on the vehicle's CO₂ emissions and registration date, so you know exactly what you're committing to before you buy.
For the precise figure at the moment of renewal, the official gov.uk vehicle tax service is always the definitive source, since rates are set by the government and updated each April.