The Core Shift: From P11D to Real-Time
The reform removes the need for end-of-year P11D forms for most benefits. Instead, the taxable value of a benefit is “payrolled”—meaning it is added to the employee’s taxable pay in each pay period.
- Current System: Benefits are reported after the tax year (by 6 July). HMRC then adjusts the employee’s tax code for the following year to recover the tax.
- New System (Mandatory 2027): Benefits are reported via the Full Payment Submission (FPS) every payday. Tax is deducted immediately in real-time.
- The 2026 Opportunity: Employers can (and are encouraged to) voluntarily register to payroll benefits for the 2026/27 tax year by 5 April 2026.
Benefit Scope: What’s In and What’s Out?
While the goal is to digitize all benefits, some complex items have different timelines.
| Benefit Category | Status (from April 2026/27) |
| Common Benefits (Health insurance, gym, cars) | Mandatory Payrolling (from 2027) |
| Fuel & Mileage | Mandatory Payrolling (from 2027) |
| Beneficial Loans (e.g., Director loans) | Excluded from mandate; Voluntary only |
| Living Accommodation | Excluded from mandate; Voluntary only |
Note: For excluded benefits, the traditional P11D and P11D(b) process will remain in place until further notice from HMRC.
The “Double Tax” Effect (First-Year Impact)
The most sensitive part of this transition is the impact on employee take-home pay during the first year of payrolling.
- The Problem: In the first year of the new system, an employee may have their tax code “kicked” by a previous year’s P11D (collecting old tax) while simultaneously paying tax on this month’s benefits in real-time.
- The Result: A significant, one-off drop in net pay.
- Mitigation: Hewitt’s Payroll should advise clients to contact HMRC to “spread” any previous year underpayments over multiple years to ease the cash-flow burden on staff.
Class 1A National Insurance (NICs)
Under the current system, Class 1A NICs are a lump sum paid by the employer in July.
- The Change: From April 2027, Class 1A NICs must also be calculated and paid in real-time through the payroll.
- Cash Flow Tip: Businesses must prepare for a shift from one large annual payment to 12 smaller monthly payments. This helps with budgeting but requires tighter month-end cash management.
Preparation Roadmap for Hewitt’s Payroll
Registration Deadlines
If a client wants to “practice” for the 2027 mandate, they must register for voluntary payrolling through the HMRC Online Service before 6 April 2026. You cannot register mid-year.
Data Accuracy & “Reasonable Estimates”
For benefits where the exact cost isn’t known (e.g., variable medical premiums), HMRC allows for “reasonable estimates” to be payrolled. At the end of the year, a reconciliation process will allow for a final adjustment by 6 July.
Software Audit
Ensure your payroll software is updated to handle:
- Adding “Notional Pay” (the benefit value) for tax/NIC calculation without it increasing the actual net cash paid to the employee.
- Generating the Annual Statement for employees (required by 1 June) showing the total value of benefits payrolled in the year.
Employee Communications
The transition is often confusing for staff. A clear communication plan should explain:
- Why their tax code has changed (HMRC will remove the benefit from the code).
- Why the “Double Tax” effect might happen.
- How to read the new “Benefit in Kind” line on their payslip.