P11D reporting: an employer's guide to benefits in kind

Every UK employer that provides a company car, private medical insurance or an interest-free loan above £10,000 has to tell HMRC about it, and the deadline is fixed: 6 July after the end of the tax year ^[1]. Class 1A National Insurance on those benefits runs at 15% for the 2026-27 tax year, and it is paid entirely by the employer, never the employee ^[2].

P11D reporting is the mechanism that puts a cash value on the perks an employer hands out and feeds the tax and National Insurance due on them back to HMRC. It sits outside the normal payrun, follows its own calendar, and carries its own penalty regime. For a growing business that has just started offering benefits, or an accountant picking up a new client mid-year, the rules reward preparation and punish guesswork.

This article sets out what P11D reporting covers, the forms involved, the deadlines that matter, how Class 1A National Insurance is worked out, which benefits are exempt, the penalties for filing late, and the structural reform that will retire the P11D for most benefits from April 2027.

Key takeaways

• P11D and P11D(b) forms are due to HMRC by 6 July after the tax year ends, with employee copies due the same day ^[1].
• Class 1A National Insurance on benefits in kind is charged at 15% for 2026-27 and is an employer-only cost ^[2].
• Class 1A must reach HMRC by 22 July (19 July for postal payment) ^[3].
• Paper P11D forms have not been accepted since 6 April 2023; filing is online only ^[4].
• Mandatory payrolling of benefits begins to phase in from 6 April 2027, starting with cars, vans and medical benefits ^[5].

What P11D reporting actually covers

A benefit in kind is anything of value an employer provides to an employee or director that is not cash pay. The classic examples are the company car, employer-paid private medical insurance, gym membership and low-interest loans. HMRC treats these as taxable, because they put money in the employee's pocket in a form that is not caught by the ordinary PAYE payrun ^[1]. P11D reporting is how the taxable value of those benefits reaches HMRC once the tax year has closed.

The scope is wider than many employers assume. Reimbursed expenses that are not covered by an exemption, company vans available for private use, and taxable relocation costs above £8,000 all fall inside the net ^[6]. An employer that provides even a single reportable benefit to one employee has a filing obligation, so the volume of benefits is irrelevant to whether a return is due.

The two forms: P11D and P11D(b)

P11D reporting uses two distinct forms that do different jobs. The P11D is completed per employee and lists every taxable benefit that individual received in the year. The P11D(b) is a single employer-level declaration that totals the Class 1A National Insurance due across the whole workforce ^[1]. An employer files one P11D(b) and as many P11D forms as it has employees receiving non-payrolled benefits.

The distinction matters because the two forms have different consequences if they go wrong. A missing P11D understates an individual's taxable income. A late or incorrect P11D(b) understates the employer's own National Insurance liability and is the form that attracts the automatic late-filing penalty ^[7]. The table below summarises the split.

Both forms are submitted through the same channel and by the same deadline, so in practice they are prepared together as one year-end task.

Which benefits are reportable

Whether a benefit needs a P11D depends on the type of benefit and whether the employer has chosen to payroll it. Company cars, employer-provided fuel, private medical insurance, non-exempt loans and taxable relocation packages are the most common reportable items ^[6]. Each has its own valuation rule, and the company car in particular is worked out from a percentage of list price scaled by the vehicle's carbon dioxide emissions ^[1].

The table below shows how a selection of common benefits is treated for both reporting and Class 1A National Insurance.

A benefit that is payrolled still counts towards the employer's Class 1A total on the P11D(b), even though it no longer needs its own P11D. The reporting route changes, the National Insurance does not ^[3].

The P11D reporting deadlines that matter

P11D reporting has a compact but unforgiving calendar. The submission deadline for both P11D and P11D(b) is 6 July following the end of the tax year, and the same date is the deadline for giving each affected employee a copy of the information reported about them ^[1]. Employers that run their own year-end need to plan the P11D task alongside the final Full Payment Submission and the issue of P60s, since all three cluster in the weeks after 5 April ^[8].

Payment of the Class 1A National Insurance follows two weeks later. Electronic payment must reach HMRC by 22 July, while an employer still paying by post has to allow for a 19 July cut-off ^[3]. Where an employer settles minor or irregular benefits through a PAYE Settlement Agreement instead, the associated tax and Class 1B National Insurance are due later, by 22 October ^[9].

The full sequence of dates is set out below.

Missing the 6 July submission date starts the penalty clock immediately, so the deadline is the single most important figure in the whole process. Businesses that keep clean benefit records through the year, rather than reconstructing them in June, are the ones that file comfortably ahead of it. Reliable HMRC-recognised payroll software tracks benefit values as they arise so the year-end return is a report rather than a rebuild.

Class 1A National Insurance on benefits in kind

Class 1A National Insurance is the employer's contribution on the value of most benefits in kind. For the 2026-27 tax year it is charged at 15%, the same headline rate that applies to secondary Class 1 contributions on ordinary earnings ^[2]. The defining feature of Class 1A is that it falls entirely on the employer. The employee pays Income Tax on the benefit but no National Insurance, which is what separates a benefit in kind from ordinary salary ^[10].

Class 1A applies to the same benefits that are reported on the P11D, whether or not those benefits have been payrolled. The P11D(b) is the form that pulls the whole liability together into one figure, so an employer that has moved some benefits into the payroll and left others on the P11D still declares a single combined Class 1A total ^[3].

How the 15% charge is calculated

The Class 1A charge is 15% of the total taxable value of the benefits provided in the year. For a company car, the taxable value is derived from the manufacturer's list price multiplied by an appropriate percentage set by the vehicle's emissions, and it is that final cash-equivalent figure, not the list price, that the 15% is applied to ^[1]. For private medical insurance, the taxable value is generally the premium the employer paid ^[6].

Worked through, an employee with a company car valued at £6,000 for benefit purposes and private medical cover costing £900 has a combined benefit value of £6,900. The employer's Class 1A National Insurance on that individual is 15% of £6,900, which is £1,035 ^[2]. Across a workforce, these individual figures are summed and declared on the single P11D(b), and the resulting liability is paid by 22 July ^[3]. Understanding how employer National Insurance works across both ordinary pay and benefits helps an employer see the full cost of employment, a topic covered in the guide to employer National Insurance.

Payrolling benefits: the alternative to the P11D

Since 2016, employers have had the option to tax benefits in kind through the payroll rather than reporting them on a P11D after year-end. This is called payrolling benefits, and it means the taxable value of a benefit is added to the employee's pay each period and the Income Tax is collected in real time through PAYE ^[11]. The employee sees the tax spread across the year rather than absorbed through an adjusted tax code the following year.

Payrolling removes the need to file individual P11D forms for the benefits that have been payrolled, which is a meaningful simplification for an employer with a large workforce. What it does not remove is the P11D(b): the Class 1A National Insurance on payrolled benefits still has to be declared and settled after year-end, so the employer-level return survives even when the individual forms disappear ^[11].

How to register before the tax year starts

Payrolling cannot be switched on mid-year. An employer has to register through HMRC's payrolling benefits and expenses online service before the start of the tax year, meaning before 6 April, and once registered the chosen benefits stay registered until the employer deregisters ^[11]. At registration the employer selects which benefits to payroll and can exclude specific employees where the payrolling route does not suit them ^[12].

The deadline discipline is strict because HMRC uses the registration to adjust employees' tax codes for the year ahead. An employer that misses the 5 April cut-off has to wait until the following tax year to start payrolling and reports on the P11D in the meantime ^[11]. Accountants managing benefits across many client schemes typically handle this through a payroll bureau platform that flags registration windows per employer, since the date is easy to miss when it sits just before the busiest point of the year.

What is exempt from P11D reporting

Not every payment or perk needs to appear on a P11D. HMRC operates a set of statutory exemptions that remove routine business expenses from the reporting net entirely, provided the conditions are met. Business travel, business phone calls, work uniforms and necessary work equipment are all exempt, as are subsistence costs paid at HMRC benchmark rates ^[6]. Where an employer pays the published benchmark rates, no separate application is needed; only bespoke rates require prior HMRC agreement ^[1].

The exemptions cover the reimbursement of genuine business costs, not perks dressed up as expenses. The employer either pays a flat rate approved by HMRC or reimburses the employee's actual costs, and in both cases the payment sits outside P11D reporting ^[6]. Records still matter: HMRC expects the employer to keep the date, reason and detail of each reimbursed expense for three years after the end of the tax year, so that the exemption can be evidenced if the return is later examined ^[1].

A separate route exists for benefits that are minor, irregular or hard to allocate to individuals. Under a PAYE Settlement Agreement, the employer makes a single annual payment covering the Income Tax and Class 1B National Insurance on those items, and the benefits are then kept off both the P11D and the employees' own tax affairs ^[9]. A staff event or a small gift is the sort of item a PSA is designed for.

Penalties for getting P11D reporting wrong

P11D reporting is backed by an automatic penalty regime, and the penalties fall in two places: late filing of the P11D(b) and late payment of the Class 1A National Insurance. Both run on fixed formulas, so the cost of slipping the deadline is predictable and, for a larger workforce, significant ^[13].

Late filing and late payment

A P11D(b) filed after 6 July triggers a penalty of £100 per 50 employees for each month or part-month the return is late ^[13]. Even an employer with a single employee faces the £100 charge the moment the return is a day late, because the penalty is banded rather than proportional ^[14]. The charge continues to accrue month by month until the P11D(b) is filed.

Late payment of the Class 1A National Insurance is penalised separately. Interest runs from the due date, and a late-payment penalty of 5% of the unpaid Class 1A applies once the liability is 30 days overdue, with further 5% penalties at six and twelve months ^[14]. Because the filing and payment penalties are independent, an employer can be penalised twice on the same benefits: once for the late form and once for the late money ^[15].

Correcting a P11D after submission

Errors on a submitted P11D are corrected online, and the correction has to be complete rather than incremental. A corrected P11D must show all of the employee's benefits for the year, not only the item that changed, and a corrected P11D(b) must state the total Class 1A National Insurance due rather than the difference between the old and new figures ^[1]. Since 6 April 2023, these corrections have also been online-only, in line with the wider move away from paper returns ^[4].

Getting the correction method right avoids a common trap, where an employer submits only the changed benefit and inadvertently wipes out the rest of the original return. HMRC treats the latest submission as the complete picture, so a partial resubmission can create a larger error than the one it was meant to fix ^[14].

The end of the P11D: mandatory payrolling from April 2027

The P11D is on a defined path to retirement. HMRC has confirmed that mandatory payrolling of most benefits in kind will be phased in over two years from 6 April 2027, replacing after-year-end reporting with real-time reporting through the payroll ^[5]. Once a benefit is within the mandatory regime, both the Income Tax and the Class 1A National Insurance on it are reported and paid through payroll rather than on a P11D and P11D(b) ^[16].

The phasing splits the benefit population into two tranches. From 6 April 2027, mandatory payrolling covers company cars, car fuel, vans, van fuel and employer-provided medical benefits, which between them account for the large majority of benefits provided in the UK ^[5]. From April 2028, most remaining benefits follow, with employment-related loans and living accommodation staying on a voluntary basis for the time being ^[16]. The table below sets out the two phases.

For employers, the reform reframes benefits as a payroll task rather than a year-end filing task, which raises the premium on payroll systems that calculate benefit values, apply Class 1A in real time and submit accurately through Real Time Information. An HMRC-recognised payroll API that already handles PAYE, National Insurance and RTI is built to absorb payrolled benefits without a separate year-end scramble. The final full year of traditional P11D reporting for most benefits will be the year that ends before the phasing begins, so the reform gives employers a clear window to move their processes across ^[15].

How software keeps P11D reporting clean

The mechanics of P11D reporting reward systems that capture benefit data at source. A benefit valued incorrectly, a payrolling registration missed before 6 April, or a P11D(b) total that does not reconcile with the payroll all create work and, potentially, penalties. Software that records each benefit as it is provided, values it against the current HMRC rules, and carries the Class 1A figure through to the P11D(b) turns the year-end return into a check rather than a construction job ^[11].

For a small business running payroll in-house, the priority is a tool that flags reportable benefits and the 6 July deadline. A guide to small business payroll covers how these year-end obligations fit alongside the ordinary payrun. For a bureau managing benefits across dozens of clients, the priority is a platform that tracks payrolling registrations and Class 1A liabilities per scheme, so no single client's deadline is lost in the volume. The same discipline that keeps year-end forms such as the P60 accurate keeps the P11D accurate: clean data through the year, reconciled at the close.

Conclusion

P11D reporting is a fixed-calendar obligation with a low tolerance for error. The 6 July filing deadline, the 22 July Class 1A payment date, the 15% employer-only National Insurance charge and the banded late-filing penalty combine into a process where preparation is the whole game. Employers that record benefits accurately through the year meet the deadline without drama, and those that leave it to June meet the penalty regime instead.

The larger shift is that P11D reporting itself is being replaced. From 6 April 2027, benefits move into the payroll in real time, phase by phase, until the individual P11D disappears for most benefits. The direction of travel is clear: benefits in kind are becoming a payroll calculation rather than an annual return, and the employers who move their processes across early will find the transition is a change of timing rather than a change of substance.

Frequently asked questions

What is the difference between a P11D and a P11D(b)?

A P11D is completed for each employee and lists the taxable benefits that individual received during the tax year, so it drives the Income Tax the employee owes on those benefits. A P11D(b) is a single employer-level form that totals the Class 1A National Insurance due across the whole workforce and settles the employer's liability ^[1]. An employer files one P11D(b) and as many P11D forms as it has employees with non-payrolled benefits, and both are due by 6 July.

Can an employer still submit a paper P11D?

No. Since 6 April 2023, HMRC has not accepted paper P11D or P11D(b) forms, including paper corrections ^[4]. Returns must be filed through HMRC's PAYE Online service for employers or through recognised commercial payroll software. The only remaining exception is where a business has ceased trading, which HMRC handles separately.

How much is the penalty for filing a P11D late?

A late P11D(b) attracts an automatic penalty of £100 per 50 employees for each month or part-month the return is late, so even a single-employee business faces £100 the moment the deadline passes ^[13]. Late payment of the Class 1A National Insurance is penalised separately, with a 5% charge once the liability is 30 days overdue and further 5% penalties at six and twelve months, plus interest ^[14].

Is P11D reporting being abolished?

For most benefits, yes, but in phases. From 6 April 2027, mandatory payrolling brings company cars, car fuel, vans, van fuel and medical benefits into real-time payroll reporting, and from April 2028 most other benefits follow, with loans and living accommodation staying voluntary for now ^[5]. Once a benefit is payrolled under the mandatory regime, it no longer needs an individual P11D, though the Class 1A National Insurance is still reported through payroll ^[16].