If you run a small business in the UK, you’re not dealing with one tax deadline a year. You’re dealing with several, and they don’t all follow the same calendar. Self Assessment runs on the 6 April tax year. Corporation Tax runs on your company’s own accounting period. VAT runs on quarters. Payroll runs monthly.
This guide puts every date that matters for 2026/27 in one place, organised by the tax it applies to, so you can check what’s relevant to your business and move on.
When does the UK tax year run in 2026/27?
The 2026/27 tax year runs from 6 April 2026 to 5 April 2027. Every personal tax deadline — Self Assessment, payments on account, dividend and personal allowances — is measured against this window, regardless of when your company’s own financial year ends.
This is different from the government’s financial year, which runs 1 April to 31 March, and from your company’s accounting period, which you choose when you incorporate. It’s a common source of confusion for new sole traders moving to a limited company, because personal tax and company tax suddenly stop running on the same clock.
Why the tax year starts on 6 April
The date is a leftover from the 1752 switch from the Julian to the Gregorian calendar, which shifted the UK’s dates by 11 days overnight. The tax year used to start on 25 March — an old quarter day known as Lady Day. To avoid losing 11 days of revenue, the Treasury moved the start to 5 April, then adjusted it again to 6 April around 1800 to account for a leap year discrepancy. It’s never changed since.
The full 2026/27 tax deadline calendar at a glance
Most small businesses deal with two or three of the categories below, not all of them. Scan for the ones that apply to you.
| Date | What’s due |
|---|---|
| 6 April 2026 | 2026/27 tax year begins; MTD for Income Tax becomes mandatory for qualifying income over £50,000 |
| 31 May 2026 | Give employees and directors their P60 |
| 6 July 2026 | Report expenses and benefits (P11D) |
| 7 August 2026 | First MTD quarterly update deadline (covers 6 April–5 July) |
| 5 October 2026 | Register for Self Assessment if you need to file for the first time |
| 7 November 2026 | Second MTD quarterly update deadline |
| 31 October 2026 | Paper Self Assessment tax return deadline |
| 30 December 2026 | Deadline to file online if you want tax collected through your tax code |
| 31 January 2027 | Online Self Assessment return, balancing payment, and first payment on account due |
| 7 February 2027 | Third MTD quarterly update deadline |
| 7 May 2027 | Fourth MTD quarterly update deadline |
| 31 July 2027 | Second payment on account due |
Corporation Tax, VAT, PAYE and Companies House deadlines aren’t fixed calendar dates — they’re set relative to your accounting period, VAT quarter, or payroll cycle, so they’re covered separately below.
Self Assessment deadlines 2026/27
The Self Assessment deadline for the 2025/26 tax year is 31 January 2027 for online returns, and this is also when any tax you owe is due.
You need to file if you’re self-employed and earned more than £1,000 before expenses, or if you’re a partner in a business partnership. If you’re weighing up whether a business partnership structure suits you better than trading alone, each partner still files their own return separately.
| Requirement | Deadline |
|---|---|
| Register for Self Assessment (first-time filers) | 5 October 2026 |
| Paper tax return | 31 October 2026 |
| Pay through your tax code (PAYE collection) | 30 December 2026 |
| Online tax return | 31 January 2027 |
| Pay tax owed + first payment on account | 31 January 2027 |
| Second payment on account | 31 July 2027 |
Payments on account catch people out every year. If your last tax bill was over £1,000 and less than 80% of your income was taxed at source, HMRC expects two advance payments toward next year’s bill — half by 31 January, half by 31 July. Good sole trader record-keeping habits make it much easier to estimate these payments accurately instead of guessing.
You can file any time from 6 April 2026 onward. Filing early doesn’t move your payment deadline, but it tells you your bill months ahead, which helps with cash flow planning.
Making Tax Digital for Income Tax (MTD ITSA) deadlines
Making Tax Digital for Income Tax became mandatory on 6 April 2026 for sole traders and landlords with qualifying income over £50,000. Qualifying income means gross self-employment and property income combined, before expenses — not your net profit.
Under MTD, you keep digital records and send HMRC a quarterly update instead of a single annual return.
| Qualifying income | MTD start date |
|---|---|
| Over £50,000 | 6 April 2026 (now in force) |
| Over £30,000 | 6 April 2027 |
| Over £20,000 | 6 April 2028 |
If you’re in scope now, your quarterly updates for 2026/27 are due:
- 7 August 2026 — covers 6 April to 5 July
- 7 November 2026 — covers 6 July to 5 October
- 7 February 2027 — covers 6 October to 5 January
- 7 May 2027 — covers 6 January to 5 April
Limited companies aren’t affected by MTD for Income Tax and continue filing Corporation Tax returns as normal.
What’s replacing the End of Period Statement
Earlier guidance on Making Tax Digital referred to an End of Period Statement (EOPS) after the final quarterly update. HMRC’s current timeline for 2026/27 has moved past that step: instead, you submit a Final Declaration directly through your MTD software by 31 January 2027, which finalises your tax position for the year. If you’re reading older guidance that still mentions EOPS, it hasn’t caught up with this change.
Corporation Tax deadlines for limited companies
Corporation Tax has two separate deadlines, and the payment date comes before the filing date. You pay what you owe nine months and one day after your accounting period ends, then file the return that calculates it up to three months later.
| Requirement | Deadline |
|---|---|
| Pay Corporation Tax | 9 months and 1 day after your accounting period ends |
| File your Company Tax Return (CT600) | 12 months after your accounting period ends |
So if your accounting period ends 31 December 2026, your Corporation Tax payment is due 1 October 2027, and your CT600 isn’t due until 31 December 2027. It’s an easy pair of dates to mix up, and understanding both is part of the broader set of company director responsibilities in the UK.
2026/27 Corporation Tax rates and marginal relief
For 2026/27, companies with profits up to £50,000 pay the small profits rate of 19%. Companies with profits above £250,000 pay the main rate of 25%. Profits between those two figures get marginal relief, which tapers the rate gradually rather than jumping straight from 19% to 25%.
Here’s the part most guides skip: within that £50,000–£250,000 band, the effective marginal rate on each additional pound of profit is actually 26.5% — higher than the 25% main rate itself. A company earning £100,000 in profit pays a higher rate on its last pound of profit than a company earning £300,000. This is a genuine quirk of the 3/200 marginal relief formula, and it’s worth knowing before you assume “smaller company, lower rate” always holds.
If you control more than one company, the £50,000 and £250,000 thresholds are split between them. Two associated companies each get a £25,000 small profits threshold and a £125,000 main rate threshold, not the full amounts.
Companies House deadlines
Companies House deadlines run alongside HMRC deadlines but are separate filings, with separate penalties for missing them.
| Requirement | Deadline |
|---|---|
| Confirmation statement | Within 14 days of your review period ending |
| Annual accounts | 9 months after your accounting reference date |
Your accounting reference date is set automatically when you incorporate — it’s the last day of the month you registered, or its first anniversary. If you’ve recently gone through the first steps after registering a company in the UK, this date will already be sitting in your Companies House record, and it’s worth calendaring immediately. Your registered details, including your registered office address, also need to be current when you file your confirmation statement — it’s a criminal offence to miss this filing entirely, not just a fine.
VAT deadlines for 2026/27
Most VAT-registered businesses file quarterly, with the return and payment due one calendar month and seven days after the quarter ends.
You must register once your VAT-taxable turnover passes £90,000 in a rolling 12-month period — not a fixed tax year, so it’s worth checking your rolling total regularly rather than just at year-end.
| Scheme | Return deadline |
|---|---|
| Standard | 1 month + 7 days after the VAT period ends |
| Cash Accounting | 1 month + 7 days after the VAT period ends |
| Flat Rate | 1 month + 7 days after the VAT period ends |
| Annual Accounting | 2 months after the 12-month accounting period ends |
The standard VAT rate is 20%. The Flat Rate Scheme is open to businesses expecting turnover under £150,000 in the next 12 months, and can simplify VAT accounting for smaller operations. All VAT-registered businesses must file through Making Tax Digital-compatible software — there’s no manual submission route left.
PAYE and payroll deadlines
If you employ anyone, PAYE deadlines repeat every tax month rather than landing once a year.
| Requirement | Deadline |
|---|---|
| Full Payment Submission (FPS) | On or before each payday |
| Employer Payment Summary (EPS), if needed | By the 19th of the next tax month |
| Pay PAYE and National Insurance (electronic) | By the 22nd of the next tax month |
| Give employees their P60 | By 31 May |
| Report expenses and benefits (P11D) | By 6 July |
If your total PAYE and National Insurance bill averages under £1,500 a month, HMRC classes you as a small employer and lets you pay quarterly instead — on the 22nd of April, July, October and January.
Capital Gains Tax deadlines for business assets
If you sell or dispose of a business asset — property, shares, equipment that’s appreciated in value — you may owe Capital Gains Tax.
- Property disposals: report the gain and pay any tax due within 60 days of completion.
- Other business asset gains: report through Self Assessment and pay by 31 January following the end of the tax year in which you disposed of the asset.
The 60-day property window is short, and it runs from completion, not from when you eventually file your annual return — treat it as a separate, faster deadline.
Dividend and personal allowance changes to plan around in 2026/27
If you’re a limited company director paying yourself through a mix of salary and dividends, two figures are worth checking before you plan your extraction strategy for the year.
The personal allowance stays frozen at £12,570 for 2026/27, and the dividend allowance stays at £500. What’s changed is the rate charged above those allowances: following the Autumn Budget 2025, dividend tax rates rose by 2 percentage points from April 2026, to 10.75% (basic rate), 35.75% (higher rate) and 39.35% (additional rate).
For a director taking a standard £12,570 salary and drawing the rest as dividends, this rate rise directly increases the tax bill on the same dividend amount compared with 2025/26 — worth factoring into how much you set aside during the year, not just at filing time.
What happens if you miss a small business tax deadline?
Missing the Self Assessment deadline triggers an automatic £100 penalty the moment you’re late, even if you don’t owe any tax. From there, penalties escalate the longer a return stays outstanding.
| How late | Penalty |
|---|---|
| Immediately after 31 January | £100 automatic penalty |
| More than 3 months late | £10 per day, up to £900 |
| More than 6 months late | A further £300 or 5% of tax owed, whichever is higher |
| More than 12 months late | Another £300 or 5% of tax owed, whichever is higher |
A return that’s a full year late can carry more than £1,600 in penalties before interest, which continues to accrue on any unpaid tax from 1 February. Corporation Tax, VAT and PAYE each carry their own separate penalty regimes rather than sharing this one.
If you have a genuine reason for filing late — illness, bereavement, a software failure outside your control — you can appeal a penalty by explaining what happened. HMRC calls these “reasonable excuses,” and they’re assessed case by case rather than automatically accepted.
FAQs
Can I file my Self Assessment return before the tax year ends? No — HMRC’s online filing service for a given tax year typically opens on 6 April after that year ends. For the 2025/26 tax year, that means you can file any time from 6 April 2026, well ahead of the 31 January 2027 deadline.
Do tax deadlines shift if the date falls on a weekend? The tax year dates themselves never move. But if a payment or filing deadline lands on a weekend or bank holiday, HMRC generally treats it as on time if it clears by the next working day.
Is the government’s financial year the same as the tax year? No. The personal tax year runs 6 April to 5 April. The government’s financial year runs 1 April to 31 March. Corporation Tax rates are set against the financial year, which is why a company accounting period straddling 31 March can technically span two different rate periods.
Do I need to do both Self Assessment and Making Tax Digital? If your qualifying income is over £50,000 from self-employment and property combined, MTD replaces the traditional annual Self Assessment return with quarterly updates plus a Final Declaration — you don’t do both in parallel once you’re in scope.
Does my company’s accounting period have to match the tax year? No. Companies House sets your first accounting reference date based on your incorporation month, and you can change it later if needed. Many directors align it with 31 March or 31 December for simplicity, but your personal Self Assessment deadlines still run on the 6 April to 5 April cycle regardless of your company’s year end.
