On most cars, excise duty is the largest single charge, often larger than the customs duty. It is set by the Excise (Special Provisions) Act and by gazettes that list a rate for each engine size, so it depends on the vehicle and not on its price.
What decides the rate
- The tax class. Petrol, diesel, hybrid, plug-in hybrid and electric cars each have their own table. See import tax by vehicle type.
- The engine capacity in cc for petrol, diesel, hybrid and plug-in hybrid cars. A larger engine falls in a higher band with a higher rate for every cc.
- The motor power in kW for electric vehicles, and for them the age of the vehicle as well.
- The age or the weight for some vans, trucks and buses.
How to read a band table
Each row of a table is a band, for example "1,001 – 1,300 CC", with a rate per cc or a fixed amount. You find the band your engine falls in, and the duty is the engine capacity multiplied by that band's rate. The whole engine is charged at the rate of its band: it is not split between bands.
The Petrol class page shows the whole table for petrol cars with a worked example for every band, and the walkthrough in how the tax is calculated follows the excise duty of a 1,000 cc car through to the total.
An engine exactly on a limit
The gazette words every band as "exceeding X but not exceeding Y". So a limit belongs to the band below it: if a band ends at 1,000 cc, an engine of exactly 1,000 cc is in that band, and 1,001 cc is in the next one. Electric vehicles follow the same rule for kW, and vehicle age is read the same way ("not more than one year old" includes a vehicle of exactly one year).
Fixed amounts and "higher of"
Some bands do not charge per cc. They charge a fixed amount, or the higher of a fixed amount and a per-cc figure. The table shows which. The calculator applies whichever the gazette sets for that band.
Electric and hybrid vehicles
An electric vehicle has no engine capacity, so its excise duty comes from kW bands and an age bracket instead. Hybrids and plug-in hybrids are charged by engine capacity like petrol and diesel cars, in classes of their own. See hybrid and electric vehicles.
Where the rates come from
The rates come from Extraordinary Gazette 2418/43 and the gazettes that amend it. The list of gazettes behind every charge is at the end of the calculator page, with links to the official copies.