P11D and Benefits in Kind Explained: What Your Employer Reports and What It Costs You

A benefit in kind is never deducted from your pay, and that is exactly why it confuses people. Your employer reports it to HMRC on a form P11D, HMRC takes the value of the benefit off the tax-free amount in your tax code, and your employer’s payroll then taxes a larger slice of the same salary. Gross pay does not move. No new line appears on the payslip. Take-home pay falls anyway. The cost to you in 2026/27 is the cash equivalent of the benefit multiplied by your marginal rate, so 20%, 40% or 45%. Your employer pays a separate charge on top of that, Class 1A National Insurance at 15%.

What counts as a benefit in kind

A benefit in kind is something your employer gives you that has a money value but is not paid to you as money. HMRC keeps an A to Z of them: company cars and vans, private medical and dental insurance, interest-free loans, living accommodation, gym and club memberships, school fees, home phone bills paid by the company, holidays, credit cards you use for personal spending, and non-cash vouchers.

Two distinctions decide whether anything happens to your tax.

• Cash versus non-cash. Anything paid to you in cash, including a round-sum allowance or a cash bonus, is treated as earnings. It goes through payroll, is taxed at source and has employee National Insurance taken off it in the normal way. It is not a benefit in kind at all.
• Taxable versus exempt. A large number of things your employer pays for are specifically exempt, so they never reach a P11D. Business travel, one annual health screening, eye tests required by health and safety rules for screen users, and workplace canteen meals are all in that group.

Everything left over is taxable, and each benefit has its own valuation rule. That valuation is the number that drives your tax code, and it is rarely the price your employer paid.

The P11D and the P11D(b): two forms doing two different jobs

People use “P11D” as shorthand for the whole process, but there are two forms and they do different jobs.

The P11D is per person. It lists the benefits and expenses one named director or employee received in the tax year, each in its own lettered section, with a cash equivalent for every entry. It is a tax return of your benefits, filed by your employer on your behalf, and it is what HMRC uses to set your tax code.

The P11D(b) is per employer. It is a single declaration for the whole payroll that says how much Class 1A National Insurance the employer owes on all those benefits added together. HMRC describes it as the form used “to declare the amounts of Class 1A National Insurance contributions you’re due to pay for the year”.

Both must be filed by 6 July after the end of the tax year, so the 2026/27 forms are due by 6 July 2027. Both must go in online, through PAYE Online for employers or commercial payroll software. Paper is only accepted if the employer has stopped trading or is formally digitally exempt, which is a change a lot of small employers still get caught by. If you run a payroll yourself, our P11D generator will lay out the cash equivalents section by section before you key them into HMRC’s service.

Your employer must also give you the information on your P11D by 6 July. Ask for it: it is the only place the figures are itemised.

Class 1A National Insurance: your employer’s bill, not yours

This is the part that gets mixed up most often. On a benefit in kind you pay income tax and no employee National Insurance. Your employer pays employer-only Class 1A National Insurance instead, at 15% for 2026/27, on the same cash equivalent HMRC taxes you on.

So a £2,000 benefit costs a basic-rate employee £400 in income tax and costs the employer £300 in Class 1A. Nothing at all comes off your National Insurance. If you want to see how your own NI is worked out on the cash part of your pay, the rules are in our guide to National Insurance rates for 2026/27.

Class 1A is due by 22 July if the employer pays electronically, or 19 July by cheque. Filing the P11D(b) late costs £100 per 50 employees for each month or part month it is late, which is why payroll departments get twitchy in late June.

How a benefit actually reaches your tax code

Here is the mechanism, in the order it happens.

• Your employer values the benefit under HMRC’s rules and reports the cash equivalent on your P11D.
• HMRC starts with your Personal Allowance, £12,570 in 2026/27, and takes the benefit off it. GOV.UK gives exactly this worked example: a medical insurance benefit of £1,570 taken off the Personal Allowance leaves a tax-free amount of £11,000, so the code becomes 1100L.
• HMRC issues that code to your employer. Payroll applies it, usually on a cumulative basis, so the correction for the months already gone catches up in the first pay packet the new code touches.
• Because HMRC assumes the benefit continues, the same deduction is carried into the following year’s code as an estimate.

Notice what does not happen. Nothing is deducted for “medical insurance”, gross pay is unchanged, and only the tax line moves. If your code is a mystery to you, start with what UK tax codes mean and why most people have 1257L.

Worked example: Nadia, private medical insurance

Nadia earns £34,000 and her employer starts paying £1,410 a year for private medical cover from 6 April 2026. Her salary does not change.

The tax: £1,410 × 20% = £282 for the year, or £23.50 a month. Her tax code drops from 1257L to 1116L, because £12,570 minus £1,410 is £11,160. Her employer pays Class 1A of £1,410 × 15% = £211.50, which never appears on Nadia’s payslip at all.

Now the bit that causes the phone calls. HMRC does not always get the code out on 6 April. Say the new code reaches payroll in September, month 6. Because it is cumulative, September’s pay carries six months of catch-up at once: 6 × £23.50 = £141 extra tax in that single month, on top of nothing having changed in her gross pay. From October she is back to £23.50 a month more than she used to pay. Over the full year she pays exactly £282, but she felt it as one bad September.

Worked example: Sam, company car and free fuel

Sam earns £58,000, so he is a higher-rate taxpayer. He has a petrol company car with a list price of £34,000 and CO2 emissions of 175g/km, which sits in the top band, and his employer also pays for his private fuel.

• Car benefit: £34,000 × 37% = £12,580
• Fuel benefit: the 2026/27 multiplier of £29,200 × 37% = £10,804
• Total cash equivalent: £23,384

Sam’s income tax on that is £23,384 × 40% = £9,353.60 a year, about £779 a month. His employer’s Class 1A is £23,384 × 15% = £3,507.60.

His benefits are larger than his Personal Allowance: £12,570 minus £23,384 is minus £10,814. That produces a K code, here K1080. A K code is a negative allowance, so instead of sheltering pay it adds an amount to be taxed. HMRC applies a hard stop: the tax taken on any one pay day cannot exceed 50% of that period’s gross pay. Before you sign a company car order form, run the numbers through our company car tax calculator, and look hard at the free fuel. Sam is paying £4,321.60 a year in tax for fuel that would have to cost more than that in personal mileage to be worth taking.

Worked example: Ravi, an interest-free loan from work

Ravi borrows £22,000 from his employer, interest free, and holds it all year. Loans are only exempt if the combined outstanding balance stays under £10,000 throughout the whole tax year, so this one is reportable.

The benefit is the interest he did not pay, at HMRC’s official rate of 3.75% from 6 April 2026: £22,000 × 3.75% = £825. As a higher-rate taxpayer Ravi pays £825 × 40% = £330 in tax, and his employer pays £123.75 in Class 1A. Had the loan been £9,500 and never gone above it, there would have been nothing to report at all. Directors borrowing from their own company have a second problem on top of this one, covered in our guide to director’s loans and the S455 charge.

How the common benefits are valued

Exempt benefits and the trivial benefits rule

Plenty of things your employer buys you are not taxable and never touch your code: one health screening or medical check-up a year, eye tests required by health and safety law for display screen users, glasses or contact lenses prescribed solely for screen work, and up to £500 of medical treatment paid for to help you return to work.

Then there is the trivial benefits exemption, which is genuinely useful and widely misunderstood. A benefit is exempt if all four of these are true:

• it cost your employer £50 or less to provide
• it is not cash or a cash voucher
• it is not a reward for your work or performance
• it is not in the terms of your contract

Break any one of those and the whole thing is taxable, not just the excess above £50. A £52 hamper is a £52 benefit. If you are a director of a close company there is an extra ceiling: no more than £300 of trivial benefits in a tax year.

Payrolling benefits: the alternative to a P11D

An employer can choose to tax benefits through the payroll instead of reporting them at the year end. This is called payrolling, and it changes what you see: the cash equivalent is added to your taxable pay each period and taxed there and then, so the tax is spread evenly, your code is not reduced for that benefit, and no P11D is issued for it.

Two things stay the same. The employer still has to work out Class 1A and file a P11D(b). And two benefits cannot be payrolled at all: living accommodation and interest-free or low-interest loans. Those still go on a P11D.

Employers must register to payroll before 6 April of the tax year in question, and cannot switch method part-way through a year. From April 2027 the choice largely disappears: HMRC is mandating real-time reporting through payroll software for medical benefit, company cars, vans, and car and van fuel, with employer loans and accommodation continuing through the existing end-of-year process until April 2028. We have set out the detail in our guide to payrolling benefits in kind from April 2027.

The practical upshot for employees: if your benefits are payrolled, your tax code should not be reduced for them. If it has been reduced as well, you are being taxed twice on the same benefit. That is the single most common payrolling error and it is worth checking with our tax code checker.

The trap: your code drops mid-year and you assume HMRC is wrong

The classic sequence: you join a scheme in May, nothing happens for months, then in November a coding notice arrives, your code falls, November’s net pay is noticeably down, and you conclude HMRC has blundered. The following April your code changes again and you conclude they have blundered twice.

Usually neither is a mistake. The first drop is the benefit being priced in plus the catch-up for the months already run. The second change is HMRC carrying the estimate forward, sometimes alongside collecting an underpayment from the year that has just closed. HMRC lists “your employer tells HMRC you have started or stopped getting benefits from your job” as a standard reason a code changes.

What to do instead of assuming an error:

• Get your P11D copy from your employer and check each cash equivalent against reality. A car you handed back in August should be time-apportioned, not charged for a full year.
• Sign in to HMRC’s Check your Income Tax service and look at the benefit figures held against you. You can correct estimates there yourself.
• Watch for benefits that have ended. HMRC keeps taxing an estimated benefit until someone tells it the benefit stopped, and that is money out of your pocket every month until you do.
• If a change is needed, HMRC says it will tell you and your employer the new code within 15 working days, and it will show on your next or the following payslip if you are paid monthly.
• Model the effect before you panic. Put your salary into our take-home pay calculator with the reduced code to see what the monthly figure should be.

One more thing worth knowing when you change jobs. Your P45 carries your pay and tax to date but says nothing about benefits, so a benefit from the old job can keep sitting in your code at the new one until HMRC is told otherwise. Our guide to what a P45 actually contains explains what does and does not transfer.

Key dates and rates for 2026/27

Rates and thresholds are from HMRC’s rates and thresholds for employers 2026 to 2027, the deadlines from GOV.UK expenses and benefits deadlines, and the tax code mechanism from GOV.UK on what your tax code means. Income tax rates shown are those for England and Northern Ireland; if you are a Scottish taxpayer the bands differ, and our comparison of Scottish income tax against England sets out by how much.

If a benefit has just started, work out its cash equivalent, multiply by your marginal rate and divide by the pay days left in the tax year. That is what the code change will feel like, and it will be worse than a twelfth of the annual figure because of the catch-up. If the amount on your P11D does not match what you actually received, go back to your employer first: HMRC codes whatever the employer reported, right or wrong.