How we work

We use the rates GOV.UK and HMRC publish, and show every step of every sum.

Our rules

Vehicle tax rates come from GOV.UK's vehicle tax rate tables. Company car percentages come from HMRC's Employment Income Manual, and mileage rates, the car fuel benefit multiplier and the van benefit charge from HMRC's published rates and allowances. Income Tax rates come from HMRC, the same records our sister site Work Calculators uses. Each figure is recorded with its source and the date we checked it, and the site will not build if one is missing. You can see them all.

Keeping rates up to date

Vehicle tax changes every April, and company car percentages and mileage rates can change with each Budget. A script reads GOV.UK's and HMRC's own pages and checks every table against the headings it expects, so a change in their layout stops the update instead of slipping a wrong figure in. Old rates are kept, not edited.

Our calculators give information, not advice. They work from what you enter. For your own tax, HMRC's records and your tax code are what count.

How we test the sums

Every calculation is tested against GOV.UK's and HMRC's own tables: a new electric car pays £10 and then the standard rate, a car over the list price threshold pays the supplement for five years, a diesel's company car percentage stops at HMRC's maximum, and 12,000 business miles come to the approved amount at both mileage rates.

Corrections

We have not had to correct any figure yet. If you spot a mistake, email max@youellsystems.co.uk.