Compliance Reference · Tax Year 2026/27
Every deadline a UK small business needs to track for 2026/27 — HMRC, Companies House, payroll, VAT, MTD, ICO, and the consequences of missing each one. Organised by month and by tax. Updated for the post-April-2026 rules.
For the 2025/26 tax year: paper returns due 31 October 2026; online returns and balancing tax due 31 January 2027. First payment on account for 2026/27 also due 31 January 2027; second payment on account due 31 July 2027. Register for Self Assessment by 5 October 2026 if you became self-employed during 2025/26.
| Date | What's due | Who it applies to |
|---|---|---|
| 5 October 2026 | Register for Self Assessment if you became self-employed, started receiving rental income, or otherwise became chargeable in 2025/26. | New self-employed, landlords, etc. |
| 31 October 2026 | Paper SA return deadline for 2025/26. | Anyone filing on paper |
| 30 December 2026 | PAYE collection option — file online by this date if you want HMRC to collect tax owed via your PAYE code (under £3,000, must have PAYE income). | Employed with side income |
| 31 January 2027 | Online SA return + balancing payment + first POA for 2025/26. Most-missed deadline in UK tax. | Everyone in SA |
| 31 July 2027 | Second payment on account for 2026/27. | SA taxpayers with POA |
If you're unsure whether you need to file Self Assessment, see our Self Assessment guide. Common triggers: self-employed earning over £1,000, rental income over £1,000, total income over £150,000, HICBC charge, capital gains over the annual exempt amount.
MTD ITSA started 6 April 2026 for sole traders and landlords with qualifying income over £50,000. Threshold drops to £30,000 from April 2027, then £20,000 from April 2028. Mandated taxpayers must file 4 quarterly updates plus a Final Declaration each year, all through MTD-compatible software.
| Quarter | Period covered | Update due |
|---|---|---|
| Q1 2026/27 | 6 April – 5 July 2026 | 7 August 2026 |
| Q2 2026/27 | 6 July – 5 October 2026 | 7 November 2026 |
| Q3 2026/27 | 6 October 2026 – 5 January 2027 | 7 February 2027 |
| Q4 2026/27 | 6 January – 5 April 2027 | 7 May 2027 |
| Final Declaration | Full year 2026/27 | 31 January 2028 |
Note: The final balancing payment for the 2026/27 tax year is still due 31 January 2028 — the Final Declaration replaces the old Self Assessment return, but the payment date is unchanged. You can elect for calendar quarters (Apr–Jun, Jul–Sep, Oct–Dec, Jan–Mar) instead of standard tax-year quarters, which most accountants find easier to manage alongside VAT.
If you're not sure whether MTD ITSA applies to you in April 2026, try our MTD ITSA Diagnostic — it walks through the qualifying income test and tells you what you need to do.
Corporation Tax is paid 9 months and 1 day after the end of your company's accounting period. The CT600 return is filed 12 months after period end. From 1 April 2026, late-payment penalties doubled — HMRC late-payment interest now runs at base rate + 4% (was base rate + 2.5%).
| Date | What's due |
|---|---|
| 1 January 2027 | Pay Corporation Tax for the year ended 31 March 2026 |
| 31 March 2027 | File CT600 return for the year ended 31 March 2026 |
| Date | What's due |
|---|---|
| 1 October 2026 | Pay Corporation Tax for the year ended 31 December 2025 |
| 31 December 2026 | File CT600 return for the year ended 31 December 2025 |
Quarterly instalment payments (QIPs): companies with profits over £1.5 million (annualised, adjusted for associated companies) pay Corporation Tax in quarterly instalments, not in a single 9m+1d payment. The first instalment is due 6 months and 13 days from the start of the accounting period. Very large companies (profits over £20m) pay even earlier. Most micro-businesses will never hit this.
For 2026/27 rates: small profits rate 19% (profits up to £50,000), marginal relief between £50,000 and £250,000 (effective rate ~26.5% in that band), main rate 25%. Try our Corporation Tax Calculator.
Limited companies must file: Annual Accounts at Companies House within 9 months of year-end (small/micro companies), and a Confirmation Statement (CS01) every 12 months. Missing accounts triggers automatic financial penalties starting at £150; missing the Confirmation Statement is a criminal offence and can lead to the company being struck off.
| Filing | Deadline | Penalty if late |
|---|---|---|
| Annual Accounts (small/micro company) | 9 months after year-end | £150 (under 1 month late) up to £1,500 (over 6 months late); doubled if late two years running |
| Confirmation Statement (CS01) | Annually, by 14 days after the anniversary of incorporation or last statement | Criminal offence; company can be struck off; directors personally liable |
| Accounts for first year | 21 months from incorporation | Same scale as ongoing accounts penalty |
| Changes to officers/PSCs | 14 days from change | None automatic, but inaccurate register is an offence |
Companies House fee changes (effective from 2024): Confirmation Statement fee is now £34 online (was £13). Incorporating a new company online is £50 (was £12). These are part of the funding model for ECCTA (Economic Crime and Corporate Transparency Act) reforms, including identity verification through ACSPs.
See our Year-End Accounts Guide for the full process from period-end to filed accounts.
VAT returns and payments are due 1 month and 7 days after the end of each VAT period. Most businesses file quarterly. All VAT-registered businesses must file digitally through MTD-compatible software. The compulsory registration threshold is £90,000 (rolling 12-month turnover).
| VAT period ends | Return + payment due |
|---|---|
| 31 March | 7 May |
| 30 April | 7 June |
| 31 May | 7 July |
| 30 June | 7 August |
| 31 July | 7 September |
| 31 August | 7 October |
| 30 September | 7 November |
| 31 October | 7 December |
| 30 November | 7 January |
| 31 December | 7 February |
| 31 January | 7 March |
| 28/29 February | 7 April |
VAT registration: compulsory if your taxable turnover exceeds £90,000 in any rolling 12-month period (the threshold rose from £85,000 on 1 April 2024). You can also register voluntarily below this. Deregistration threshold is £88,000.
VAT has its own penalty regime — a points-based system for late submissions (4 points triggers a £200 penalty for quarterly filers), plus separate late-payment penalties tiered by how late you are.
Run an FPS (Full Payment Submission) on or before each payday. Pay PAYE and NIC by 22nd of the following month (electronic) or 19th (post). End-of-year deadlines tightly clustered between April and July.
| Date | Action |
|---|---|
| On/before payday | Submit FPS (Full Payment Submission) for each pay period |
| 19th of month | PAYE/NIC payment deadline if paying by post |
| 22nd of month | PAYE/NIC payment deadline if paying electronically |
| Date | What's due |
|---|---|
| 5 April 2026 | End of 2025/26 tax year |
| 19 April 2026 | Final FPS / EPS for 2025/26 |
| 31 May 2026 | Issue P60s to all employees (in employment on 5 April 2026) |
| 6 July 2026 | P11D and P11D(b) returns due for 2025/26 (benefits in kind) |
| 22 July 2026 | Class 1A NIC on benefits in kind — payment due (electronic) |
| 31 July 2026 | PAYE Settlement Agreement (PSA) payment deadline |
2026/27 employer NIC notes: Employer NIC rate is 15% on earnings above the Secondary Threshold (£5,000). Employment Allowance is £10,500 (most small employers can claim this, reducing employer NIC bills materially). NLW is £12.71/hour; SSP £123.25/week (day-one entitlement from April 2026); SMP £194.32/week.
Employer-provided benefits (private medical insurance, company cars, beneficial loans, etc.) are reported on form P11D for each employee, and a summary form P11D(b) calculates the Class 1A NIC.
| Date | What's due |
|---|---|
| 6 July (annually) | P11D and P11D(b) submission to HMRC; copies to employees |
| 22 July (annually) | Class 1A NIC payment (electronic) |
| 19 July (annually) | Class 1A NIC payment if paying by post |
P11D changes from April 2026: the option to payroll most benefits in kind through PAYE is becoming the default approach, with full mandatory payrolling for most BIKs expected from April 2027 (some categories deferred). If you payroll benefits, you don't need to file P11Ds for them — but the Class 1A NIC is still due, and a P11D(b) is still required.
If you're a contractor in construction, you must verify subcontractors, deduct CIS tax (usually 20%), and file a monthly CIS return by the 19th of the following month. CIS deductions are paid over to HMRC together with PAYE by the 22nd (electronic).
| Date | What's due |
|---|---|
| 19th of month | Monthly CIS300 return covering payments to subcontractors in the previous tax month |
| 22nd of month | Pay CIS deductions to HMRC (electronic) together with PAYE |
Most UK businesses that process personal data must register with the Information Commissioner's Office (ICO) and pay an annual Data Protection Fee. Tier 1 (micro): £52/year. Tier 2 (small/medium): £78/year. Tier 3 (large): £3,763/year. Renewal is annual.
You're exempt from the fee only if you process personal data solely for staff administration, accounts, advertising your own goods/services, or as a not-for-profit. Most accounting clients, retailers, professional services and online businesses must register.
Penalty for non-registration: up to £4,350 civil monetary penalty. Register or check status at ico.org.uk/registration.
Our clients don't worry about these dates — we do. Compliance calendar, reminders, and filings all handled within our monthly packages. Starter from £45/month.
Book a free 20-min callThe combined calendar below pulls every recurring deadline into a single month-by-month view. This is what your accountant's diary looks like.
A quick reference of what it actually costs to miss the major deadlines:
| Deadline missed | Penalty |
|---|---|
| Self Assessment (31 Jan) | £100 fixed (immediate) · £10/day after 3 months (up to £900) · 5% of tax due (or £300) at 6 months · another 5% (or £300) at 12 months · interest on unpaid tax (base + 4%) |
| Corporation Tax (CT600) | £100 (1 day) · further £100 (3 months) · 10% of unpaid tax (6 months) · further 10% (12 months) |
| VAT return | Points-based: 1 point per late submission. At 4 points (quarterly filers), £200 fixed penalty per subsequent default. Separate late-payment penalties: 2% of tax at 15 days late, 4% at 30 days, then daily 4% annual rate from day 31 |
| PAYE / FPS late | Per-month per-band: £100 (1–9 employees), up to £400 (250+). Up to 5% penalty for unpaid PAYE |
| Companies House Accounts | £150 (under 1 month) · £375 (1–3 months) · £750 (3–6 months) · £1,500 (over 6 months) · doubled if late two consecutive years |
| Confirmation Statement | Criminal offence; directors may face personal prosecution; company may be struck off |
| P11D / P11D(b) | £100 per 50 employees per month late, plus interest on Class 1A NIC |
| MTD ITSA quarterly update | Points-based system mirroring VAT (4 points = £200 per subsequent default). Starts properly accumulating from 2027/28 |
| ICO registration | Up to £4,350 civil monetary penalty |
Most penalties can be appealed if you have a "reasonable excuse" — serious illness, bereavement, IT failure of HMRC's own systems, postal disruption. Forgetting, being too busy, or relying on a third party are not usually reasonable excuses. If you have a genuinely good reason, appeal quickly — HMRC's appeals window is usually 30 days from the penalty notice.
Online filing and tax payment: 31 January 2027. Paper filing: 31 October 2026. The first payment on account for 2026/27 is also due 31 January 2027; the second payment on account for 2026/27 is due 31 July 2027.
Pay 9 months and 1 day after your company's accounting period ends. File the CT600 return within 12 months. From 1 April 2026, late-payment penalties doubled, and HMRC late-payment interest is now base rate + 4%.
6 April 2026 for sole traders and landlords with qualifying income over £50,000 (assessed from the 2024/25 SA return). 6 April 2027 for £30,000+. 6 April 2028 for £20,000+. Mandated taxpayers must file 4 quarterly updates plus a Final Declaration through MTD-compatible software.
1 month and 7 days after the end of each VAT period. Most businesses file quarterly. For a quarter ending 31 March, the return and payment are due 7 May. All VAT must be filed digitally through MTD-compatible software.
FPS on or before each payday. Monthly PAYE/NIC: 22nd of the following month (electronic) or 19th (postal). 19 April: final FPS/EPS for previous tax year. 31 May: P60s to employees. 6 July: P11D/P11D(b). 22 July: Class 1A NIC payment.
Every limited company must file a Confirmation Statement (CS01) at least once every 12 months, by 14 days after the anniversary of incorporation or the last statement. Fee is £34 online. Missing this is a criminal offence and can lead to the company being struck off.
Automatic £100 fixed penalty (even if no tax owed). Then £10/day for up to 90 days after 3 months. After 6 months: 5% of unpaid tax (or £300 if greater). After 12 months: another 5% (or £300). Plus interest on unpaid tax. Can be appealed if you have a reasonable excuse.