When does mandatory payrolling of benefits in kind start?

HMRC is phasing it in from April 2027. Employers can payroll benefits voluntarily before then, which is worth doing as a rehearsal because it lets you find data problems while the annual P11D still exists as a fallback.

Does payrolling benefits change how much tax is due?

No. It changes when the tax is collected, not how much. The cash equivalent is added to taxable pay each period so tax is deducted through the year rather than recovered afterwards through a tax code adjustment.

Which benefits cause the most trouble for small employers?

Company vehicles and anything with mixed business and private use, because the valuation depends on facts that change during the year. Beneficial loans and benefits bought on a company card without being formally recorded are the other common gaps.

Can this be handled without changing payroll software?

Often yes. The usual gap is not the payroll system but the path between someone approving a benefit and payroll finding out about it. Closing that path with a shared register and automatic alerts solves most of the problem.

Mandatory Payrolling of Benefits in Kind: What UK SMEs Should Do Before April 2027

HMRC is making payrolling of benefits in kind mandatory, phased in from April 2027. For most benefits this replaces the annual P11D with real-time reporting through payroll, so tax and Class 1A National Insurance are collected across the year rather than settled afterwards. The work that decides whether the switch is painless happens now, in the 2026 to 2027 tax year.

The change itself is administrative. The risk is not. Moving from an annual return to real-time reporting removes the twelve-month buffer in which errors were quietly corrected before anyone saw them.

What actually changes for a small employer?

Today, most SMEs report benefits once a year on a P11D, and the employee's tax code is adjusted afterwards. Under mandatory payrolling, the cash equivalent of the benefit is added to taxable pay each period, and the tax comes off at the time.

	P11D today	Payrolled from April 2027
When the benefit is reported	Once, after the tax year	Every pay period
When the employee pays tax	Later, via a tax code change	At the time
When an error surfaces	Up to a year later	Within a pay cycle
Correcting an error	Amended return	Adjustment in a later period

The last two rows are the ones that matter. An error in a payrolled benefit reaches the employee's payslip almost immediately, which is better for them and less forgiving for you.

Why 2026 to 2027 is the year that decides it

Two jobs are worth doing before the switch, and neither is quick if left late.

Build an accurate benefits inventory. Most small businesses have benefits nobody has formally listed: a vehicle used privately, private medical cover, a phone contract in the company name, an interest-free loan above the threshold, subscriptions bought on a company card. Each has its own valuation rule. If the list is wrong, the payrolled figure is wrong every single period rather than once a year.

Fix the data path. The cash equivalent has to reach payroll before each run. If a benefit change today travels by email to whoever does payroll, that path will not survive twelve runs a year without a miss.

What to automate, and what not to

Do automate the movement of data and the reminders:

A single register of benefits per employee, with the valuation basis recorded next to each one
An alert when a benefit starts, changes or ends, routed to whoever runs payroll
A pre-run check that flags any employee whose benefit value changed since the last period
A month-end reconciliation between the register and what payroll actually processed

Do not automate the valuation judgement. Company car figures, beneficial loan rules and the treatment of mixed business and private use are areas where a wrong assumption applied automatically is worse than the same assumption applied by hand, because it repeats silently.

A sensible sequence for the next two quarters

List every benefit currently provided, including informal ones
Confirm the valuation basis for each with your accountant
Register for voluntary payrolling for 2026 to 2027 if you are ready, so you meet the mandatory regime with a year of practice behind you
Connect the benefits register to payroll so changes travel automatically
Run a reconciliation for two or three months and fix what it surfaces

Voluntary payrolling before it becomes compulsory is the cheapest rehearsal available. Errors found in a year when the P11D still exists as a backstop are considerably easier to deal with than errors found in the first mandatory year.