The UK tax year for individuals runs from 6 April to 5 April, creating a unique fiscal calendar that affects everything from your pay slips to your annual tax bill. Missing key dates within this period can trigger automatic penalties and interest charges from HMRC. This article walks you through exactly what you need to know about the 2026/27 tax year, the critical deadlines ahead, and how to stay compliant.
Key Takeaways:
- The 2026/27 UK tax year runs from 6 April 2026 to 5 April 2027, and most personal allowances and reliefs reset on the first day of each new tax year.
- The main Self Assessment deadlines are 31 October 2026 for paper returns covering 2025/26 and 31 January 2027 for online returns and balancing payments.
- VAT, PAYE and Corporation Tax follow their own quarterly or annual timetables, which often do not line up exactly with the personal tax year dates.
- Penalties for late filing start at £100 and escalate quickly, while late payment interest currently runs at 7.75%.
The Taxcom can handle registrations, ongoing submissions and HMRC correspondence for individuals, landlords and limited companies so they stay compliant throughout every UK tax year.
What Is the UK Tax Year?
The UK tax year is the 12-month period HMRC uses to calculate income tax and related allowances for individuals. Unlike a calendar year starting in January, the tax year begins on 6 April and ends on 5 April the following year.
For example, the 2026/27 tax year spans 6 April 2026 to 5 April 2027. All income, gains and deductions within this window are aggregated for your tax calculation.
Many personal tax rules reset annually on 6 April, including:
- The Personal Allowance (currently £12,570)
- The ISA contribution limit (£20,000)
- The pension annual allowance (£60,000)
- The Capital Gains Tax annual exempt amount (£3,000)
Your self assessment tax return captures everything you earned and the gains you made during a specific UK tax year. Even if your business accounts use different dates, Self Assessment mandates reporting based on this April-to-April framework.
Why Does the UK Tax Year Run from April to April?
The unusual 6 April start date has medieval roots tied to rent collection and a calendar switch that happened centuries ago.
Before 1752, the UK used the Julian calendar, and the tax year began on 25 March, Lady Day, a traditional quarter day for collecting rents and land taxes. When Britain adopted the Gregorian calendar in 1752, 11 days were skipped (jumping from 2 September to 14 September).
To preserve the same number of chargeable days in the tax year, the start was shifted from 25 March to 5 April. A further adjustment in 1800 pushed the date one more day to 6 April, where it has remained ever since. This creates an important distinction:
| Period Type | Dates | Used For |
| Personal tax year | 6 April – 5 April | Income Tax, NI, allowances |
| Government financial year | 1 April – 31 March | Budgets, spending, policy |
The fiscal year for government and the tax year for individuals are related but offset by five days, a quirk that continues to confuse taxpayers and businesses alike.
UK Tax Year vs Accounting Year vs Financial Year
Individuals, businesses and government bodies often work to different “year” periods, which can cause confusion when managing finances.
Personal tax year (6 April – 5 April): This governs individual income tax, national insurance contributions and personal allowances like marriage allowance transfers.
Company accounting period: A limited company can choose any 12-month period for preparing accounts and corporation tax returns. Common choices include 1 April to 31 March or 1 January to 31 December.
Government financial year (1 April – 31 March): Used for Budget announcements, public spending and policy formulation, this is when tax rates announced in the Finance Act typically take effect.
Sole traders and partnerships can select accounting periods that differ from the tax year. However, this can complicate Self Assessment calculations through basis period apportionments. Recent reforms are pushing unincorporated businesses toward tax-year alignment, which may cause transitional changes in how much tax is calculated in a single year.
The Tax Com can advise on choosing and changing year-ends to minimise complications.
Key UK Tax Year Dates for Individuals (2026/27)
These are the main personal tax dates around the 2026/27 tax year that you should have in your diary:
- 5 April 2026: Final day of the 2025/26 tax year. Last chance to use that year’s ISA allowance, make pension contributions (subject to rules), and utilise your Capital Gains Tax annual exempt amount.
- 6 April 2026: The tax year begins for 2026/27. This is also the first date you can submit an online Self Assessment return for 2025/26.
- 31 July 2026: Deadline for making the second payment on account towards your 2025/26 Self Assessment bill, where payments on account apply.
- 5 October 2026: Deadline to register with HMRC for Self Assessment if you need to file a return for the first time for 2025/26.
- 31 October 2026: Filing deadline for paper Self Assessment tax returns for 2025/26.
- 31 January 2027: Key deadline to file your 2025/26 Self Assessment return online and pay any balancing tax due, plus the first payment on account for 2026/27.
Your tax code, PAYE calculations and student loan deductions are all based on income received within each tax year. If your circumstances change mid-year, HMRC may adjust your code accordingly.
Key UK Tax Year Dates for Employers and Limited Companies (2026–2027)
Employers and limited companies must track PAYE, VAT and Corporation Tax deadlines alongside personal tax dates.
PAYE obligations:
- Monthly payroll deductions (PAYE and Class 1 NIC) must reach HMRC by the 22nd of the following month if paying electronically (19th by post)
- Tax months run from the 6th to the 5th (tax month 1 is 6 April – 5 May 2026)
- The PAYE year ends on 5 April 2027, with Full Payment Submissions and final Employer Payment Summary due shortly after
Employee forms:
- P60 for 2025/26 must be issued to employees by 31 May 2026
- P11D and P11D(b) for expenses and benefits in kind for 2025/26 are due to HMRC by 6 July 2026
- Class 1A NIC on benefits is payable by 22 July 2026 if paying electronically
VAT deadlines: Standard quarterly VAT returns and payments are due one month and seven days after the period end. For example, a VAT quarter ending 30 June 2026 must be filed and paid by 7 August 2026.
Corporation Tax:
- Payment is usually due 9 months and 1 day after the end of a company’s accounting period
- A period ending 31 March 2026 has a Corporation Tax payment deadline of 1 January 2027
- Corporation tax returns (CT600) are due 12 months after the accounting period ends
The Tax Com maintains deadline calendars for clients, submits payroll, VAT and Corporation Tax returns on time, and represents businesses in all HMRC dealings.
How Income Tax Works Within the UK Tax Year
Income tax for most people is calculated based on total taxable income received between 6 April and 5 April. Employees typically pay tax through PAYE, where employers use a tax code from HMRC to deduct tax and national insurance from each payslip. The cumulative system aims to spread your annual liability evenly across pay periods.
People with untaxed income, such as self employment profits, rental income, dividends or foreign income, often need to file a Self Assessment tax return after the UK tax year ends.
The Personal Allowance (the amount you can earn before paying income tax) is set for each UK tax year and can change annually. For recent years it has been frozen at £12,570. Different income types attract different rates:
| Income Type | Basic Rate | Higher Rate | Additional Rate |
| Salary/wages | 20% | 40% | 45% |
| Dividends | 8.75% | 33.75% | 39.35% |
| Savings interest | 20% | 40% | 45% |
Allowances like the dividend allowance and savings allowance are also applied on a tax-year basis. Student loan repayments follow similar rules, with thresholds updated each April.
The Tax Com can review your tax position each year, adjust estimates and help ensure the right amount of tax is deducted through PAYE or reported via Self Assessment.
Self-Employed, Landlords and the UK Tax Year
Sole traders, partners and landlords are heavily affected by how the tax year is defined, especially under Self Assessment.
Self-employed profits and rental profits are reported on the tax return for the UK tax year in which the accounting period falls. Basis period reforms mean many unincorporated businesses are now aligned more closely to the tax year, which can cause one-off changes in how much trading profits are taxed in a particular year.
Keeping digital records throughout each tax year makes it much easier to:
- File accurate tax returns soon after 5 April
- Plan for tax bills due the following January and July
- Track allowable expenses properly
Landlords should track rents received, allowable expenses (repairs, letting agent fees, allowable finance costs) and void periods within each UK tax year. Remember that you need to report rental income based on when tenants pay rent, not when it was due.
The Taxcom can set up cloud bookkeeping, provide access to accounting tools and resources, review expenses, handle Self Assessment filings and advise whether to trade as a sole trader or via a limited company.
Making Tax Digital and Digital Record-Keeping by UK Tax Year
Making Tax Digital (MTD) is HMRC’s long-term initiative to move businesses toward digital record-keeping and regular online submissions.
MTD for VAT already applies to all VAT-registered businesses, requiring digital records and returns filed through compatible software.
From April 2026, self-employed individuals and landlords with gross income above £50,000 are expected to comply with MTD for Income Tax Self Assessment (subject to final rules). This threshold is expected to drop to £30,000 in later years.
Under MTD for Income Tax, affected taxpayers will:
- Send quarterly updates to HMRC on a quarterly basis
- Submit an end-of-period statement
- File a final declaration
These submissions align with tax quarters (6 April – 5 July, etc.), making it increasingly important to track income and expenses by UK tax year rather than calendar year.
The Tax Com helps clients move onto MTD-ready software, design simple quarterly processes and, where needed, deal with VAT investigations while ensuring submissions match the correct tax-year quarters.
Penalties, Interest and What Happens If You Miss a Tax Year Deadline
Missing tax deadlines triggers late-filing penalties, late-payment penalties and interest charges that can quickly accumulate over successive tax years.
Self Assessment penalties:
- £100 fixed penalty if your return is one day late (even if no tax is due)
- £10 per day after 3 months (up to 90 days)
- 5% of unpaid tax after 6 months
- Additional 5% after 12 months
Interest charges: Late payment of income tax or corporation tax attracts interest from the due date until paid in full. The current rate is 7.75%.
Other regimes: VAT, PAYE and Corporation Tax each have their own penalty structures, including surcharges and points-based systems for repeated late submissions.
If you realise you will miss a payment deadline, contact HMRC quickly to discuss a Time to Pay arrangement or consider whether an HMRC voluntary disclosure may be appropriate. The Taxcom can support negotiations and help with realistic cashflow planning to manage debt effectively.
Using a professional accountant to manage deadlines across several tax years greatly reduces the risk of unnecessary penalties.
How The Taxcom Supports You Through Each UK Tax Year
The Taxcom is a UK accountancy and tax practice focused on small businesses, contractors, landlords and individuals, staffed by professionally qualified accountants. The firm provides more help than just filing returns, they manage the entire compliance calendar.
Services include:
- Registering clients for Self Assessment, VAT, PAYE and Corporation Tax before the start of a new tax year
- Ongoing bookkeeping, payroll and VAT services to meet monthly and quarterly obligations, supported by a full range of expert accountancy and taxation services
- Preparing and filing annual accounts and corporation tax returns aligned with chosen year-ends
- Proactive financial planning before each tax year ends (for example, ahead of 5 April 2026 or 5 April 2027) to maximise new allowances and reliefs
- Representing clients in all HMRC correspondence
Contact The Taxcom to discuss about tax-year deadlines. The value of professional support becomes clear when allowances kick in at the right time and penalties are avoided.
Frequently Asked Questions About the UK Tax Year
Can I Submit My Self Assessment Tax Return Before the Tax Year Ends?
You cannot file a Self Assessment tax return until the UK tax year has finished on 5 April, because HMRC requires complete information for the full period.
However, you can keep records up to date and prepare draft figures during the year so you’re ready to file soon after 6 April. Early filing after the year-end still uses the normal payment deadlines, you don’t have to pay tax immediately just because you file early.
Do VAT Quarters Have to Match the UK Tax Year?
VAT accounting periods are set based on your registration details and do not have to align with the personal tax year of 6 April to 5 April.
Many businesses run VAT quarters such as January–March, April–June, July–September and October–December, which overlap two different tax years. Use clear accounting software to track VAT and tax-year deadlines separately.
What Is a ‘Tax Month’ and a ‘Tax Week’ for Payroll?
HMRC uses “tax months” and “tax weeks” that follow the UK tax year pattern, starting on 6 April rather than the 1st of the month.
For example, tax month 1 runs from 6 April to 5 May, and tax week 1 runs from 6 April to 12 April. PAYE calculations, student loan deductions and some National Insurance calculations use these tax periods rather than calendar months.
Can I Change My Company’s Accounting Year to Match the UK Tax Year?
Limited companies can usually change their accounting reference date with Companies House, subject to rules about frequency and direction of changes.
Aligning a company year-end with 31 March or 5 April can simplify tax treatment for owner-managers, but it’s not always the best choice for every business. Speak to The Tax Com before changing your year-end so the implications for Corporation Tax, accounts preparation and cashflow are fully understood.
What Should I Do If I Realise I Have Underpaid Tax for a Past Tax Year?
If you discover you underpaid tax for a previous UK tax year, act quickly rather than waiting for HMRC to contact you, especially as this can sometimes trigger or follow from an HMRC tax fraud investigation. In many cases you can amend your Self Assessment return online within the amendment window (12 months from the filing deadline).
For issues outside this window, HMRC’s digital disclosure service allows voluntary corrections. The Tax Com can review your position, calculate the correct liability across affected tax years, and help negotiate with HMRC to minimise penalties where possible.