Calculate the tax you pay on company benefits in kind reported on form P11D.
This calculator provides estimates for guidance only. BIK rules are complex and may vary by benefit type. Always verify with HMRC or a qualified tax adviser.
A P11D is an official HMRC form that employers use to report the taxable benefits and expenses provided to employees during the tax year. If you receive any company benefits -- such as a company car, private medical insurance, gym membership, or an interest-free loan -- you are required to pay income tax on the cash equivalent value of those benefits. This is known as a Benefit in Kind (BIK), and the amount of tax you owe depends on both the value of the benefit and your marginal income tax rate. Understanding your P11D liability is important because it directly affects your take-home pay. The tax on benefits is usually collected through an adjustment to your PAYE tax code, meaning you pay a little more tax each month rather than receiving a separate bill. However, if the amounts are significant -- such as with a high-value company car -- the impact on your monthly pay can be substantial. Knowing the true cost of your benefits helps you make informed decisions about which ones to accept. This calculator covers the most common types of P11D benefits and uses the correct HMRC rates for the 2026-27 tax year. For company cars, the BIK percentage is based on CO2 emissions. For interest-free loans, the BIK is calculated using the HMRC official interest rate. For other benefits, the full cash equivalent value is treated as the BIK.
Follow these steps to calculate the tax on your company benefit: 1. Select the type of benefit you receive. Choose from company car, private medical insurance, gym membership, interest-free loan, or other benefit. The type affects how the BIK value is calculated. 2. Enter the benefit value. For a company car, enter the list price (P11D value) including any optional extras. For medical insurance, enter the annual premium your employer pays. For a loan, enter the total loan amount. For other benefits, enter the cash equivalent value. 3. Select your tax band. Choose basic rate (20%), higher rate (40%), or additional rate (45%) based on which band the majority of your income falls into. This determines how much tax you pay on the benefit. 4. For company cars, expand the advanced options and enter the CO2 emissions in g/km. This determines the BIK percentage applied to the car's list price. You can find this figure in your car's V5C log book or the manufacturer's specifications. 5. View the results. The calculator shows the BIK value, annual and monthly tax, and the net value of the benefit after tax. The pie chart breaks down the benefit into the tax portion and the net value you receive.
Benefit in Kind tax is calculated differently depending on the type of benefit. For most benefits (private medical insurance, gym membership, other), the BIK value equals the full cash equivalent -- the amount it would cost you to buy the benefit yourself. The tax is then simply the BIK value multiplied by your marginal tax rate. For company cars, the BIK value is the car's list price multiplied by a BIK percentage that depends on CO2 emissions. Zero-emission electric cars have a BIK rate of just 2%. For petrol cars, the rate starts at 15% for vehicles emitting 1-50g/km of CO2 and increases by 1% for every additional 5g/km bracket, up to a maximum of 37%. Diesel cars that do not meet the RDE2 standard attract a 4% surcharge, also capped at 37%. For interest-free or low-interest loans from your employer, the BIK is calculated using the HMRC official interest rate, which is 2.25% for the 2026-27 tax year. The BIK value is the loan amount multiplied by this rate. If you pay some interest, only the difference between the official rate and what you pay is taxable. The net benefit value represents what the benefit is effectively worth to you after accounting for the tax. This helps you compare the true cost of a benefit against paying for it yourself from post-tax income.
Not all employee benefits are taxable. Common exempt benefits include: employer pension contributions, workplace parking, mobile phones (one per employee), workplace canteen meals available to all staff, cycle-to-work scheme bikes, and the first GBP 8,000 of qualifying relocation expenses. For company car benefits, if you make a personal contribution towards the cost of the car (capital contribution), this reduces the P11D value used to calculate the BIK. However, contributions towards running costs (fuel) do not reduce the BIK value. The tax on P11D benefits is normally collected by adjusting your PAYE tax code. HMRC reduces your Personal Allowance by the BIK value, which spreads the tax evenly across the year. You should see this reflected in your tax code notice (form P2) and on your payslip. If you stop receiving a benefit during the tax year, contact HMRC to update your code and avoid overpaying tax.