P11D & Class 1A NIC Reconciliation Checklist 2026
For employers filing the 2025/26 tax year returns
Why This Checklist Matters
Most employers treat P11D season as done once the form's submitted. It isn't.
Class 1A NIC on those benefits is due by 22 July (19th if paying by post), and interest starts the moment it's late. Errors in benefit reporting rarely surface immediately — they tend to get flagged by HMRC months later, once they've quietly compounded.
Catching a mismatch now costs nothing. Catching it in a compliance check later usually doesn't.
This checklist helps you cross-check benefit values against what you actually reported — because if you haven't double-checked your figure, it's worth five minutes before Wednesday.
Key Dates at a Glance
| Deadline | What's Due |
|---|---|
| 6 July 2026 | File P11D and P11D(b) forms digitally |
| 6 July 2026 | Give each employee a copy of their P11D information |
| 19 July 2026 | Class 1A NIC deadline if paying by post/cheque |
| 22 July 2026 | Class 1A NIC deadline if paying electronically |
⚠️ Paper forms are no longer accepted. Submissions must be made via HMRC's PAYE Online service or commercial payroll software.
Class 1A NIC: The Basics
- Rate for 2025/26: 15% of the total reportable benefit value
- Who pays: Employers only — there is no equivalent employee contribution
- How to pay: Use your Accounts Office reference number with 2613 appended (no spaces). The '26' identifies the 2025/26 tax year; '13' identifies the payment as Class 1A NIC.
💡 Don't get this wrong: Using the wrong reference means HMRC can't allocate your payment. It will sit unallocated, you'll get late payment notices, and interest will accrue — even though you actually paid.
Penalties: The Real Cost of Getting It Wrong
| What Goes Wrong | The Cost |
|---|---|
| P11D(b) filed late | £100 per 50 employees for each month (or part month) late |
| Class 1A NIC paid late | Interest charged from the due date |
| Unpaid >30 days after deadline | 5% late payment penalty |
| Unpaid at 6 months | Additional 5% penalty |
| Unpaid at 12 months | Further 5% penalty |
Example: A business with 15 employees files the P11D(b) 3 months late. That's £300 in late filing penalties alone — before any interest or late payment penalties on the NIC itself.
Your 5-Step Reconciliation Checklist
Step 1: Gather Your Source Data
Before you check anything, pull together:
- All benefit provider statements (private medical insurance premiums, car lease details, gym memberships, etc.)
- Payroll records showing what's been processed through payroll
- Finance records showing payments made to suppliers on behalf of employees
- Records of any "making good" payments (where employees reimbursed you for benefits)
📌 Pro tip: Hybrid working has increased the risk of errors. Carefully distinguish between qualifying business expenses and taxable homeworking benefits, particularly where equipment or allowances exceed HMRC exemption limits.
Step 2: Check Every Benefit Category
Run through this list and tick off each benefit your business provides:
| Benefit Type | Reported? | Value Correct? |
|---|---|---|
| Company cars and fuel | [ ] | [ ] |
| Private medical insurance | [ ] | [ ] |
| Gym memberships | [ ] | [ ] |
| Beneficial loans (interest-free or low-interest) | [ ] | [ ] |
| Living accommodation | [ ] | [ ] |
| Assets available for private use | [ ] | [ ] |
| Non-business expenses reimbursed | [ ] | [ ] |
| Gifts not covered by trivial benefits exemption | [ ] | [ ] |
| Personal bills paid by the company | [ ] | [ ] |
Common omissions to watch for: Private medical insurance, beneficial loans, gym memberships, living accommodation, and non-business travel expenses.
📌 Trivial benefits reminder: To qualify for exemption, benefits must cost £50 or less, not be cash or cash vouchers, and not be provided as a reward for services. Directors of close companies have an annual cap of £300 on exempt trivial benefits.
Step 3: Reconcile Benefit Provider Data Against Payroll/Finance Records
For each benefit:
- What did the provider invoice you? (e.g., PMI annual premium)
- What value did you report on the P11D?
- Do they match?
If they don't match, investigate why. Common causes:
- Incorrect valuation (e.g., using depreciated book value rather than market value when first provided)
- Missing benefits that were provided but never recorded
- Double-counting or missing "making good" arrangements
💡 Key check for company cars: Double-check the P11D value (the list price including VAT and options, but excluding first registration fees) and the exact CO₂ g/km for every vehicle.
Step 4: Verify Your Class 1A NIC Calculation
The maths is simple but worth checking:
Total reportable benefit value × 15% = Class 1A NIC due
For example, if your total benefits across all employees are £100,000:
Class 1A NIC = £100,000 × 15% = £15,000
Cross-check: Does the figure on your P11D(b) match your calculation? If not — reconcile before you pay.
⚠️ Even if you payroll benefits voluntarily, you still need to complete a P11D(b) by 6 July 2026 to calculate and declare the Class 1A NIC due.
Step 5: Confirm Payment Is Ready (and Correctly Referenced)
Before 22 July:
- Amount: Is the payment amount correct?
- Reference: Is it your 13-character Accounts Office reference + 2613?
- Timing: Electronic payments need to clear by 22 July — don't leave it to the last minute
- Record: Keep confirmation of payment
📌 Payment reference format: [Accounts Office reference]2613 — no spaces. Example: 123AB456789012613
Final Pre-Submission Check
Before you hit submit on 6 July, ask yourself:
- [ ] Have I included every taxable benefit provided?
- [ ] Have I valued each benefit correctly?
- [ ] Have I accounted for any "making good" arrangements (employee reimbursements)?
- [ ] Does my P11D(b) total match my sum of all P11D benefits × 15%?
- [ ] Have I given each employee their copy of the P11D information?
- [ ] Do I have the correct payment reference ready for the Class 1A NIC payment?
- [ ] Have I diarised 22 July for the electronic payment?
What's Changing: Payrolling from April 2027
The 2025/26 tax year (filed in July 2026) is the last full year of traditional P11D reporting for most employers.
From 6 April 2027, payrolling of most benefits becomes mandatory. Most benefits will be reported through payroll in real time rather than via the P11D.
Two exceptions (which remain on a voluntary payrolling basis): living accommodation and employee loans.
What this means for you now:
- You still need to file P11Ds for 2025/26 and 2026/27
- You still need to submit a P11D(b) and pay Class 1A NIC even if you payroll benefits voluntarily
- Start auditing your benefits now so nothing is missed when you transition
Need Help?
If any of this feels unclear — or if you'd rather not risk a costly error — Morgan Reach Accountancy can help with:
- Reviewing your benefits register
- Preparing and submitting P11D and P11D(b) forms
- Calculating Class 1A NIC
- Advising on exemptions and "making good" arrangements
- Getting your business ready for mandatory payrolling in 2027
Don't leave it until it's too late. A five-minute check now could save you hundreds in penalties and interest later.
This checklist is for guidance purposes only and does not constitute professional advice. Always consult your accountant or tax adviser for advice specific to your circumstances.
Morgan Reach Accountancy — Your partner in payroll compliance
