The UK tax year dates catch some people out, even those who deal with them regularly. When does the financial year end in the UK?

Ask when the financial year ends and some people assume the answer is 31 December. Others will suggest it lines up with their company accounts. 

However, neither is quite right and that misunderstanding often shows up when deadlines approach. For small business owners and the self-employed, the tax year shapes how income is reported, when allowances apply and the type of planning that is possible. 

A good grasp of UK tax year dates helps you stay organised and avoid last-minute surprises. Here’s how the tax year works, why it is set out the way it is and what it means for your tax position.

Key points: UK tax year dates

  • The UK tax year runs from 6 April to 5 April
  • These dates apply to personal tax, not company accounts
  • Income and allowances follow the tax year
  • The tax year does not match the calendar year
  • Planning around the tax year can make tax easier to manage

What is the tax year in the UK?

The tax year is the time period HMRC uses to assess personal income for tax.

Instead of using the calendar year, HMRC groups income into a fixed 12-month window known as the tax year.

Any income you receive during that time counts towards the same tax year. This includes self-employed profits, rental income, dividends, savings interest and employment income taxed through PAYE.

The tax year gives HMRC a consistent way to apply allowances, tax bands and reliefs. It also provides a clear cut-off point for reporting income.

People often mix up the tax year with other financial periods they deal with. To reiterate, it is not the same as the calendar year and it is not automatically the same as a company’s accounting year.

When does the tax year start and end? (UK)

The UK tax year starts on 6 April and ends on 5 April the following year.

These dates remain the same every year: they do not shift for weekends, bank holidays, or leap years.

If you earn income on 5 April, it belongs to one tax year. If you earn income on 6 April, it belongs to the subsequent one.

For anyone wondering when does the tax year start and end on any given year in the UK, this is the key point to remember – the new tax year always begins on 6 April.

Why are these the tax year dates?

The UK tax year dates might seem somewhat awkward or out of sync, especially when many other systems use January to December.

  • The reason has nothing to do with modern tax rules and everything to do with history. Before the 18th century, Britain used a different calendar.
  • When the country switched calendars, several days were removed to correct the date. To avoid losing tax revenue, the start of the tax year was moved forward rather than shortened.
  • Over time, this adjustment settled on early April. Once the system was in place, changing it again would have caused widespread disruption.

While the background rarely matters in practice, it explains why the UK tax year does not follow the calendar year.

Who do these tax year dates affect?

The tax year affects most people who earn income in the UK, even if they never complete a tax return themselves.

  • If you are self-employed, the tax year decides which income and expenses appear on each Self Assessment return. It also influences when payments are due and how they are calculated.
  • Landlords also need to follow the tax year. Rental income is assessed based on when it arises within the tax year, not when the return is submitted.
  • If you’re a director of a limited company, things can feel a little more complex. 
  • A company can choose its own accounting year, but personal income such as salary and dividends still falls within specific tax years.
  • Employees under PAYE are affected too – but this process is handled automatically. Tax codes and allowances are reset at the start of each new tax year, even if nothing else appears to change.

Note: the tax year start and end date are not the only time when taxes are due. Take a look at our blog for more detail on this.

How do I manage my taxes around the tax year?

Managing tax becomes more straightforward once you treat the tax year as a reference point rather than a deadline to worry about.

  • Keeping records organised by tax year makes it easier to see what belongs together. This helps when preparing returns and reduces the risk of missed income or expenses.
  • The end of the tax year on 5 April can also be a useful planning moment. In some cases, the timing of income or costs can affect how much tax is due.
  • Many allowances and thresholds reset when the new tax year starts. Knowing this allows you to plan ahead instead of reacting later.
  • Simple steps, like setting reminders for early April, can make a real difference. For small business owners, planning ahead and a little bit of preparation can save a lot of stress when it comes to submitting a tax return.
  • If your income comes from more than one source, professional advice can add clarity. An accountant can help you plan across tax years rather than dealing with issues after the fact.

Supporting small businesses and the self-employed are among our core accountancy services should you feel you would benefit from some additional support.

FAQs: When does the tax year start? (UK)

What are the UK tax year dates?

The UK tax year runs from 6 April to 5 April. These dates apply every year.

When does the financial year end in the UK?

For individuals, the tax year ends on 5 April. For companies, the financial year end depends on the accounting period chosen.

Is the tax year the same as the financial year?

No. The tax year applies to personal income, while the financial year usually relates to company accounts.

When does the new tax year start in the UK?

The new UK tax year starts on 6 April. Any income earned from that date falls into the next tax year.

Why does the UK tax year not start in January?

The dates come from historical calendar changes made centuries ago. The system has remained in place to avoid disruption.

Final thoughts: When does the UK tax year start?

Once you understand UK tax year dates, many tax decisions become easier to time.

Knowing when the financial year ends helps you plan income, expenses and allowances with more confidence. That matters whether you work for yourself, run a small company, or earn income alongside a job.

Take a look at our popular articles for further reading:

If you want help in avoiding accounting errors, Accountants East London can support you. Our team works with small business owners and solopreneurs to keep tax clear, compliant, and manageable.

To find out how we can help you, contact us today.