Miss your P30 HMRC deadline by even a day and HMRC will take its cut automatically — a 5% surcharge on the unpaid amount, plus daily interest at 7.75%. For an SME running monthly payroll of £40,000, that is a penalty bill of £2,000 before interest, triggered by a missed calendar reminder. May is P30 month for almost every UK employer, and every year it catches business owners out. This guide covers what a P30 is, what you owe, when, and how to avoid the most common mistakes.
What a P30 Actually Is
A P30 is the statutory payment you make to HMRC each month to settle the PAYE income tax and National Insurance contributions (NICs) you have deducted from your employees’ pay. It is not a form you fill in — since the rollout of Real Time Information (RTI), the calculation is driven by the Full Payment Submissions (FPS) and Employer Payment Summaries (EPS) your payroll software sends to HMRC every pay run.
The name sticks around because HMRC still labels the payment reference and bank instruction as a P30. In practice, what you are paying is the combined total of: employee income tax deducted under PAYE, employee Class 1 NICs deducted from wages, employer Class 1 NICs, student loan repayments, and apprenticeship levy where it applies. If you pay construction industry scheme (CIS) deductions or make statutory payments like Statutory Sick Pay, those are netted off too.
Every UK employer running PAYE must settle the P30 monthly unless HMRC has specifically allowed quarterly payments — which only applies if your average monthly liability is under £1,500. Most SMEs exceed this threshold after their third or fourth hire.
When the P30 HMRC Deadline Falls — 19th May vs 22nd May Split
The P30 HMRC deadline depends on how you pay:
| Payment Method | Deadline | What Counts |
|---|---|---|
| Cheque by post | 19 May 2026 | Cheque must arrive at HMRC — not just be posted — by 19 May |
| Faster Payments, CHAPS, debit card | 22 May 2026 | Funds must clear into HMRC’s account by 22 May |
| Direct Debit (new) | 22 May 2026 | Collected automatically once set up — still your responsibility to confirm |
| BACS | 22 May 2026 | Allow 3 working days — initiate by 19 May at the latest |
The 19 May deadline is catching out businesses that have moved away from cheques but still have legacy calendar reminders. If 22 May falls on a weekend or bank holiday, HMRC requires the payment to clear on the last working day before. In May 2026, 22 May is a Friday — so there is no concession.
How the P30 Calculation Actually Works
Your payroll software produces the figure, but it is worth understanding how it is built up so you can spot a discrepancy before HMRC does. For a business paying £30,000 in gross monthly salary across five employees, the April 2026 P30 liability looks like this:
| Component | Amount |
|---|---|
| Employee income tax deducted | £3,240 |
| Employee Class 1 NICs (8%) | £1,680 |
| Employer Class 1 NICs (15%) | £3,750 |
| Student loan (Plan 2, one employee) | £85 |
| Total P30 liability | £8,755 |
That figure is net of any Employment Allowance claim (up to £10,500 for eligible employers in 2026/27) and any statutory payments you have advanced to staff. If you have paid statutory maternity pay, for instance, most small employers can recover 103% of it — that recovery reduces your P30 bill directly.
The 2025 Penalty Regime in Hard Numbers
HMRC restructured the PAYE late-payment penalty system in April 2025 and it bites hard. The rules now run on a points-and-surcharge basis:
| Trigger | Penalty |
|---|---|
| First late payment in a tax year | No penalty (one concession) |
| 2nd–4th late payment | 1% of unpaid amount |
| 5th–7th late payment | 2% of unpaid amount |
| 8th–10th late payment | 3% of unpaid amount |
| 11+ late payments | 4% of unpaid amount |
| More than 6 months late | Additional 5% surcharge |
| More than 12 months late | Further 5% surcharge |
| Interest on all late amounts | 7.75% per annum (simple interest, daily) |
The 7.75% interest rate is the Bank of England base rate plus 4 percentage points — and HMRC updates it every time the base rate moves. On a £10,000 unpaid P30 left outstanding for 90 days, that is roughly £179 in interest, on top of the surcharge percentage above.
How to Pay — the Reference Number Most People Get Wrong
Your payment reference is a 17-character Accounts Office Reference followed by four digits identifying the tax year and month. The format is 123PA00123456 2601. That final ‘2601’ tells HMRC the payment relates to tax month 1 of 2026/27 (which is April 2026). Use the wrong month indicator and the payment lands in the wrong period — HMRC still holds the cash, but their system shows you as late for the correct month and issues a penalty automatically.
The tax month runs from the 6th of one calendar month to the 5th of the next. So the April 2026 tax month (tax month 1) covers 6 April to 5 May, and is paid by 22 May. Many business owners assume ‘April payroll’ means ‘paid in April’ — HMRC’s system does not.
Common Mistakes Around the P30 HMRC Deadline
- Rounding to the nearest pound. HMRC’s system rejects rounded figures if they do not match your FPS submissions. Pay the exact pence every time.
- Using the prior year’s reference number. The tax year digits change on 6 April — a payment made on 22 April using last year’s reference goes into the wrong period.
- Forgetting Employment Allowance has a cap. You can only claim up to £10,500 and it phases in across the year. If you front-load it incorrectly, later P30s will be higher than expected.
- Assuming ‘no pay’ means no P30. Even if all employees were on parental leave or off sick, you still need to send an EPS to tell HMRC the liability is zero. A missed EPS is treated as a missed filing.
- Paying from the wrong account. If you have set up Direct Debit but then pay manually, both payments go through and reconciling the overpayment takes months.
Key Takeaways
- Pay by 19 May if using cheque, 22 May if using any electronic method
- Check your Accounts Office reference includes the correct tax month digits
- Review the employment allowance on your first P30 of the year to confirm it is being applied
- File an EPS even if there is nothing to pay — silence is treated as lateness
- Factor the 7.75% interest and escalating percentage surcharge into cashflow modelling
Next Steps for Your Business
If you are unsure whether your payroll is producing the correct P30 figure, or you have had a late payment in the past 12 months and want to avoid repeat penalties, we run a payroll health-check that reviews your last six months of submissions, reference numbers, and allowance claims. One conversation typically pays for itself.
Frequently Asked Questions
What is a P30 and who needs to pay it?
A P30 is the monthly PAYE payment every UK employer must make to HMRC. It covers the income tax and National Insurance deducted from employee wages plus the employer’s own NIC contribution. Any business running PAYE must pay it monthly unless HMRC has specifically authorised quarterly payments — which only applies when your average monthly liability is under £1,500.
Why are there two P30 deadlines — 19 May and 22 May?
HMRC gives three extra days when you pay electronically to allow funds to clear. Cheques must arrive by the 19th of the month after the tax month ends. Electronic payments — Faster Payments, CHAPS, BACS, debit card, or Direct Debit — must clear HMRC’s account by the 22nd. The 19th is a postal deadline; the 22nd is a funds-cleared deadline.
What happens if I miss the P30 HMRC deadline?
Your first late payment in a tax year carries no penalty. From the second late payment onwards, you pay 1% of the unpaid amount, rising to 4% by the 11th offence. Interest accrues at 7.75% a year from the due date. If the amount stays unpaid for six months, an extra 5% surcharge applies, with another 5% after twelve months.
How do I know the right reference number to use?
Your Accounts Office reference is a 17-character code HMRC issued when you registered as an employer. You then add four digits showing the tax year and tax month — so 2601 means April 2026. Check your HMRC online account under PAYE for the exact format before every payment. Using last year’s digits is the most common cause of misallocated payments.
Can I pay HMRC quarterly instead of monthly?
Only if your average monthly PAYE liability is below £1,500. You do not need to apply — HMRC will confirm eligibility when you register or at the start of a tax year. Most SMEs grow out of this threshold after a handful of hires. If you think you qualify, confirm it in writing with HMRC before changing your payment pattern.
What if I do not pay because I have no employees that month?
You still need to tell HMRC. File an Employer Payment Summary (EPS) to declare a nil liability for that tax month. Without it, HMRC assumes you owe what the prior month showed and may issue an estimated assessment plus a late filing notice. A missed EPS is treated the same as a missed payment for penalty-counting purposes.
