A company car can look like a straightforward workplace perk, but the real cost is not the same as the monthly lease figure shown in the brochure. Once a vehicle is available for private use, including normal commuting, it is usually treated as a taxable benefit. That means the car with the lowest headline payment may not be the cheapest choice after tax.
This company car tax guide UK drivers can use focuses on the numbers that matter when comparing new vehicles: the car’s official list price, its emissions, the relevant benefit-in-kind percentage and your income tax rate. Understanding those four elements makes it much easier to judge whether an electric car, plug-in hybrid, petrol model or diesel really suits your budget.
What is benefit-in-kind car tax?
Benefit-in-kind car tax, often shortened to BIK tax, is the income tax you pay when an employer provides a car that is available for personal journeys. The employer reports the taxable benefit, and the tax is normally collected through payroll or an adjustment to your tax code.
The annual taxable value is broadly calculated by multiplying the car’s taxable list price by its official BIK percentage. You then pay income tax on that taxable value at your marginal rate. The list price generally includes VAT, delivery and taxable factory-fitted accessories. Importantly, HMRC normally uses the published list price rather than the discounted price your employer or leasing company actually paid.
A simple company car tax calculation
Take a fully electric car with a taxable list price of £40,000. For the 2026/27 tax year, a zero-emission company car has a 4% BIK rate. The taxable benefit is therefore £1,600. A 20% taxpayer would pay £320 a year in income tax, while a 40% taxpayer would pay £640.
Now compare that with a £40,000 petrol car emitting 120g/km of CO2. Its 2026/27 BIK percentage is 30%, creating a taxable benefit of £12,000. That means annual tax of £2,400 at 20% or £4,800 at 40%. The cars have the same list price, but the tax difference is substantial.
How BIK rates 2026 affect your choice
The 2026/27 company car tax bands strongly favour vehicles with zero or very low emissions. Fully electric cars are taxed at 4% of their list price. Plug-in hybrids emitting between 1g/km and 50g/km are placed into bands according to their official electric-only range.
For 2026/27, a qualifying plug-in hybrid with an electric range of 130 miles or more also attracts a 4% rate. The percentage rises to 7% for a range of 70 to 129 miles, 10% for 40 to 69 miles, 14% for 30 to 39 miles and 16% for less than 30 miles. Once emissions rise above 50g/km, the rate is based mainly on the CO2 figure and increases progressively, reaching a maximum of 37%.
Diesel buyers should check the vehicle’s certification as well as its CO2 output. A diesel that does not meet the relevant Euro 6d, also known as RDE2, standard can face a four-percentage-point supplement, subject to the overall 37% cap. Most buyers should confirm the fuel type and emissions data on the employer’s quotation rather than relying on a dealer’s general description.
Do not judge a company car by BIK alone
A low BIK rate can make a vehicle attractive, but it is only one part of the total cost. In a company car scheme UK employees may also give up part of their salary, pay an employee contribution or choose a package with different levels of insurance, servicing, tyres and breakdown cover.
For a fair comparison, add together the salary sacrificed or monthly employee payment, estimated BIK tax, private fuel or charging costs and any items excluded from the package. Then compare that figure with the realistic cost of privately financing, insuring, maintaining and depreciating a similar car.
Salary sacrifice needs a separate check
Many company car schemes operate through salary sacrifice, where you give up gross salary in exchange for the vehicle. This can be efficient for qualifying low-emission cars, but the exact result depends on the scheme, your tax position and the car’s emissions. Cars with higher emissions can be affected by additional optional-remuneration rules, so use the employer’s personalised illustration rather than assuming every vehicle receives the same tax treatment.
Watch the separate private fuel charge
If your employer pays for fuel used on private journeys and you do not repay the full private-use cost, a separate car fuel benefit charge may apply. For 2026/27, the car fuel benefit multiplier is £29,200. It is multiplied by the car’s BIK percentage, and you then pay income tax on the resulting amount.
Because this is a fixed tax calculation rather than a charge based on the fuel you actually use, employer-paid private fuel can be poor value for drivers with modest personal mileage. Fully electric cars are treated differently because electricity is not regarded as fuel for the company car fuel benefit charge. Reimbursement arrangements for business charging still have their own rules and rates.
Questions to ask before ordering
Ask the fleet team for the car’s P11D or taxable list price, official CO2 emissions, electric range where relevant, fuel classification and estimated monthly BIK tax. Confirm whether the quotation uses the correct 2026/27 rate and whether any factory options will increase the taxable price.
Frequently asked questions
How is company car tax paid?
It is usually collected through PAYE, either through payroll or by adjusting your tax code. The amount can change if you swap cars, add private fuel, make contributions or lose access to the vehicle during the tax year.
Are electric company cars tax-free in 2026?
No. Fully electric company cars have a low 4% BIK rate for the 2026/27 tax year, but they are not tax-free. The actual amount depends on the car’s taxable list price and your income tax rate.
Does a more expensive car always mean more company car tax?
Not always. Emissions can have a much larger effect than price. A costly electric car may create less tax than a cheaper petrol or diesel model, although two cars in the same BIK band will generally produce more tax if one has a higher list price.
Is commuting classed as private use?
Yes, ordinary travel between home and a permanent workplace is generally treated as private use. A company car available for commuting will therefore normally create a taxable benefit.
Making the right financial choice
The best company car is not necessarily the model with the lowest lease payment, the longest equipment list or even the lowest BIK percentage. It is the one that delivers the right balance of tax, monthly contribution, practicality and running costs for your circumstances.
Before committing, calculate the annual tax using the current BIK rates 2026, review the full scheme quotation and compare the total net cost with a private purchase or lease. A few minutes spent checking the list price and emissions band can prevent an expensive surprise and help you choose a new car that genuinely makes financial sense.
