The UK tax system operates on a unique annual cycle known as the tax year. Understanding the tax year is important for employees, self-employed individuals, landlords, business owners, investors and anyone responsible for paying taxes to HMRC.
Many people search for tax year dates every year because numerous financial responsibilities depend on them. Filing tax returns, paying Capital Gains Tax, reporting rental income and managing business taxes all revolve around these dates.
If you’re involved in property ownership or investment, understanding the tax year becomes even more important because it affects rental income reporting, expense calculations and long-term tax planning.
What Is the Tax Year?
The tax year is the official 12-month accounting period used by HM Revenue & Customs (HMRC) to calculate taxes.
Unlike many countries that follow the calendar year from 1 January to 31 December, the United Kingdom tax year runs from:
6 April to 5 April the following year.
For example:
- 2025/26 tax year: 6 April 2025 to 5 April 2026
- 2026/27 tax year: 6 April 2026 to 5 April 2027
This system applies to Income Tax, Capital Gains Tax and many personal taxation obligations.
Why Does the UK Tax Year Start on 6 April?
The unusual date has historical origins dating back centuries.
Before 1752, Britain used the Julian calendar, and the tax year effectively began on 25 March. When the Gregorian calendar was adopted, 11 days were added to align dates, eventually moving the effective start date to 5 April. Another adjustment later shifted it to 6 April.
Although the history is old, the system remains unchanged today.
Tax Year UK Dates You Should Know
Several important deadlines occur throughout the year.
6 April
The new tax year officially starts.
This is when:
- New allowances may apply
- Updated tax thresholds can begin
- New tax policies may take effect
5 October
If you become self-employed or receive untaxed income for the first time, this is typically the deadline to register for Self Assessment.
31 October
Deadline for submitting a paper Self Assessment tax return.
31 January
Important date for:
- Online Self Assessment submissions
- Paying any outstanding tax owed
- Making certain tax payment on account instalments
If you are a landlord, understanding buy to let expenses calculations can help you prepare accurate figures before these deadlines arrive.
When Does the UK Tax Year Start?
The UK tax year always starts on 6 April.
Many people mistakenly assume it begins on 1 January because they associate taxes with the calendar year.
However, for UK tax purposes, 6 April is the official starting point every year.
When Does the Tax Year End in the UK?
The tax year always ends on 5 April.
All income received within this period belongs to that specific tax year.
Examples include:
- Employment income
- Rental income
- Self-employment profits
- Investment gains
- Certain pension income
Accurate record keeping throughout the year can make tax filing significantly easier.
Who Needs to Pay Attention to Tax Year Dates?
Almost everyone earning income in the UK should understand the tax year.
Employees
PAYE automatically deducts taxes, but annual tax codes and allowances still matter.
Self-Employed Individuals
You are responsible for:
- Keeping records
- Submitting Self Assessment returns
- Paying taxes on time
Landlords
Landlords must report rental income accurately.
If you’re planning on renting out property in the UK, understanding annual tax responsibilities should be one of your first priorities.
Property Investors
Property sales can trigger Capital Gains Tax obligations.
If you own multiple properties, it’s helpful to understand capital gains tax on second properties before making decisions.
Limited Companies
Although corporation tax follows accounting periods rather than the personal tax year, directors often have personal tax obligations too.
Businesses should also understand limited company tax responsibilities.
How Tax Years Affect Landlords
Property taxation has become increasingly important for UK landlords.
Every tax year, landlords need to track:
- Rental income
- Mortgage interest adjustments
- Property maintenance costs
- Insurance expenses
- Professional fees
Good record keeping throughout the year reduces the risk of errors and missed deductions.
Many landlords now work with accountants because taxation rules have become more complex.
How to Stay Organised Throughout the Tax Year
Simple habits can save considerable time.
- Keep digital copies of receipts
- Track all sources of income monthly
- Separate personal and business expenses
- Review tax changes every April
- Prepare for deadlines early
Using HMRC online services can also simplify tax management.
Can You Manage Taxes Online?
Yes.
Most taxpayers can manage various tax matters digitally.
Many people use online government systems to:
- Check tax codes
- View tax records
- Access tax calculations
- Update information
- Monitor payments
In future, understanding your UK Personal Tax Account can help streamline many administrative tasks.
Where to Find Official Tax Year Information
Rules and allowances can change each year.
Always verify dates, allowances and current requirements through official government guidance. The Income Tax rates and allowances page is a useful starting point for updated information.
Final Thoughts
Understanding the UK tax year is one of the foundations of good financial management.
Whether you’re an employee, landlord, investor or business owner, knowing when the tax year starts and ends can help you avoid penalties, improve planning and stay organised.
As tax rules continue evolving, building a strong understanding of related areas such as rental income, property taxes and business taxation will make future financial decisions much easier.
Updated November 2026: Knowing where you are in the tax year is only the starting point. The deadlines that matter most to landlords are the ones in our guide to self assessment for property income, which walks through registration, filing and payment dates step by step.
Once your dates are in order, it is worth checking you are not overpaying. Our roundup of landlord tax deductions covers the costs you can legitimately claim, and our overview of buy to let taxation explains how the main rules fit together for UK landlords.
