Company Car Tax UK: A Fleet Manager's Guide

How company car tax is calculated

When an employer provides a car that an employee can use privately, HMRC treats the private use as a Benefit in Kind. Unlike the flat rate used for vans, company car tax is calculated as a percentage of the car's P11D value — broadly its list price including VAT and most factory-fitted options — with that percentage set according to the car's CO2 emissions (and electric-only driving range for some plug-in hybrids). The resulting 'benefit' figure is then taxed at the employee's normal income tax rate through PAYE, so the same car costs a higher-rate taxpayer more per year than a basic-rate taxpayer.

Why commuting doesn't get you out of the charge

This is the single biggest difference from company van tax. A van used only for business journeys and ordinary commuting has no tax charge at all, but a company car made available for any private use — including the daily commute — triggers the Benefit in Kind charge in the normal course of events. The only realistic way to avoid it is a car that's genuinely unavailable for private use, such as being kept and used exclusively on business premises, which is impractical for most standard company car arrangements.

Key points every fleet manager should know

• Three inputs decide the bill

  P11D value, the CO2-based BIK percentage, and the employee's personal tax rate combine to set the annual Benefit in Kind charge.

• Commuting counts as private use

  Unlike vans, simply driving a company car to and from work triggers the charge — there's no 'work-only' exemption in normal circumstances.

• Electric cars sit at the bottom of the scale

  Zero-emission cars carry the lowest BIK percentages, though HMRC has published scheduled year-on-year increases — always confirm the current rate for the tax year in question.

• Fuel benefit is a separate, fixed charge

  A second charge applies if private fuel is provided without reimbursement, based on a fixed multiplier rather than actual fuel used — often avoided by requiring repayment instead.

• Reported via P11D or payrolling

  Employers report the benefit either through an annual P11D form or by 'payrolling' the benefit through real-time PAYE — the choice affects when and how the employee sees the tax deducted.

Why electric company cars are so much cheaper to tax

Government policy has deliberately used the BIK percentage scale to make electric company cars significantly cheaper from a tax perspective than an equivalent petrol or diesel model, with zero-emission vehicles sitting at the bottom of the scale and higher-CO2 vehicles at the top. HMRC has published a schedule of gradual year-on-year increases to the zero-emission rate running through the mid-2020s, so the gap narrows slightly each tax year rather than staying fixed — always check gov.uk for the confirmed percentage for the specific tax year in question before advising an employee or modelling costs, since Budget announcements can adjust the published schedule.

Reporting the benefit correctly

Employers report company car benefits either through an annual P11D form after the tax year ends, or by 'payrolling' the benefit so the tax is deducted through PAYE in real time across the year — the latter avoids employees receiving an unexpected tax code adjustment the following year. Whichever method is used, getting the underlying vehicle data right — accurate P11D value, correct CO2 figure, and the exact dates a vehicle was available to each employee — is what keeps the calculation correct. FleetGS's reporting keeps vehicle records and assignment history in one place, making that data easy to pull together at year end.

Related reading

For the equivalent rules on vans, see our company van tax UK guide. For salary sacrifice EV schemes, read our EV salary sacrifice guide. And for the full cost picture across a mixed fleet, see fleet whole life cost UK.