Tax year dates UK: when the tax year starts, ends and what is due

The UK tax year runs from 6 April to 5 April

The UK tax year runs from 6 April one year to 5 April the next, so the current 2026/27 tax year started on 6 April 2026 and ends on 5 April 2027. Section 4 of the Income Tax Act 2007 says a tax year "begins on 6 April and ends on the following 5 April", and names it by both years, as in "the tax year 2026-27".

The same 6 April to 5 April year applies to Income Tax, National Insurance, Capital Gains Tax, ISAs and pension allowances for individuals. It is not the calendar year, and it is not the 1 April to 31 March financial year that companies and councils use, which is covered further down.

Your pay is taxed against the allowances of the tax year in which it is paid. You can see what the 2026/27 rates mean for your salary with the UK take-home pay calculator.

Why the tax year starts on 6 April

The UK tax year starts in early April because of the 1752 calendar change. According to the Office of Tax Simplification's September 2021 report on the tax year end date, published on GOV.UK, the tax year "shifted from the previous date of 25 March in 1752, in association with a shift from the Julian to the Gregorian calendar".

The Calendar (New Style) Act 1750 explains the starting point. It records that the legal year in England began on 25 March, and it removed 11 days from September 1752: the day after 2 September 1752 was to be called 14 September. Adding those 11 lost days to 25 March gives 5 April, which is where the UK tax year still ends. The official sources checked for this guide do not explain the further step from a 5 April start to a 6 April start, so this guide does not repeat the popular explanations for it.

The date could change, but not soon. The same report said the reasons for 5 April are "historical and now obsolete". It looked at moving the year end to 31 March or 31 December and concluded that such a change should not take place in the immediate future, because the financial and opportunity costs for government and businesses are significant. Ireland moved its tax year to the calendar year in 2002, which the report studies in an annex.

Key tax year dates for 2026/27 and 2027/28

The key dates in each UK tax year run from the start on 6 April through quarterly Making Tax Digital updates to the Self Assessment deadline on 31 January after the year ends. The table puts the deadlines for the 2026/27 tax year and the 2027/28 tax year side by side, in date order. Each date was checked on GOV.UK on 28 September 2026.

Making Tax Digital quarterly updates apply only to people already signed up. According to GOV.UK, you had to join from 6 April 2026 if your qualifying income from self-employment and property was over £50,000 in 2024/25, and you must join from 6 April 2027 if it was over £30,000 in 2025/26. The guide to Making Tax Digital for Income Tax explains who is in and the calendar update periods you can choose instead.

Payments on account also apply only to some people: GOV.UK says you do not make them if last year's bill was under £1,000 or more than 80% of your tax was collected at source. According to GOV.UK's Self Assessment deadlines page, if you want to pay your bill through your tax code you must file online by 30 December; miss it and you pay another way.

Tax deadlines coming up after 28 September 2026

The next tax deadline after 28 September 2026 is 5 October 2026, the last day to register for Self Assessment for the 2025/26 tax year if you have not sent a return before. According to GOV.UK, if you register after 5 October 2026 you could get a penalty, and HMRC will give you a filing deadline 3 months from the date of its letter, although the tax is still due by 31 January 2027.

31 January 2027 is a Sunday. According to GOV.UK, when a deadline falls on a weekend or bank holiday your payment must reach HMRC on the last working day before it, which is Friday 29 January 2027, unless you pay by Faster Payments or by debit or credit card. The filing deadline stays at 11:59pm on 31 January 2027. See how long is left on the Self Assessment deadline countdown.

Self Assessment dates follow the tax year, even for the self-employed

Self Assessment dates follow the 6 April to 5 April tax year: you register by 5 October, file a paper return by 31 October or an online return by 31 January, and pay by 31 January and, if you make payments on account, 31 July. Each payment on account is half of last year's bill, according to GOV.UK, and the guide to payments on account covers when you can reduce them.

Worked example: £40,000 profit in 2026/27. The site's self-employed tax engine, with £40,000 income, no expenses, no salary, no student loan and England, gives Income Tax of £5,486 and Class 4 National Insurance of £1,645.80, a bill of £7,131.80. You can reproduce it in the self-employed tax calculator.

• If you paid the same amount for 2025/26, the 2026/27 bill is paid in two payments on account of £3,565.90 on 31 January 2027 and 31 July 2027, with nothing left for 31 January 2028.
• If 2026/27 is your first year of self-employment, nothing is due in 2027. On 31 January 2028 you pay £10,697.70, the whole £7,131.80 plus a first payment on account of £3,565.90 for 2027/28, and a second £3,565.90 on 31 July 2028.

The self-employed now report profit for the tax year itself. According to HMRC's guidance on the tax year basis, from 6 April 2024 you report the profit earned from 6 April to the following 5 April. If your accounts end on any date from 31 March to 4 April, you can treat them as ending on 5 April. Other year ends mean splitting profit across two sets of accounts by days. Any transition profit from the 2023/24 change is spread up to the 2027/28 tax year.

Employer dates: P60 by 31 May, P11D by 6 July

Employers must give a P60 to everyone working for them on 5 April by 31 May, and report benefits on a P11D by 6 July. According to GOV.UK, your P60 shows the tax you paid on your salary in the tax year, you get one for each job, and it can be on paper or electronic.

The end-of-year sequence for employers is set out on GOV.UK:

1. Send the final payroll report of the year on or before the employees' last payday.
2. Update payroll records and software from 6 April.
3. Give P60s to employees by 31 May.
4. Apply for a PAYE Settlement Agreement by 5 July, if you want to settle minor or irregular benefits in one payment.
5. Submit P11D forms, give employees a copy and report Class 1A on form P11D(b) by 6 July.
6. Pay Class 1A National Insurance by 22 July (19 July by cheque).
7. Pay the tax and Class 1B due under a PAYE Settlement Agreement by 22 October (19 October by post).

A late P11D(b) costs £100 for every 50 employees for each month or part month it is late, according to GOV.UK. Benefits that are payrolled through the year need no P11D, but the employer still files a P11D(b) for the Class 1A.

Allowances that reset on 6 April

Your Personal Allowance, ISA allowance and pension annual allowance all belong to a single tax year and start again on 6 April. Of the three, only unused pension annual allowance can sometimes be carried forward.

The Personal Allowance of £12,570 is set by section 5 of the Finance Act 2021, as amended, for every tax year up to and including 2030/31. According to GOV.UK, the ISA allowance is £20,000 in 2026/27 and the tax year for ISAs runs from 6 April to 5 April. GOV.UK's policy paper of 17 September 2026 confirms the cash ISA limit falls to £12,000 for savers under 65 from 6 April 2027, within the same £20,000 overall limit.

The pension annual allowance is the most you can save in pensions in a tax year (6 April to 5 April) before tax is charged, according to GOV.UK. Section 228 of the Finance Act 2004 sets it at £60,000 for 2023/24 and each later tax year. It is lower for some high earners and people who have flexibly accessed a pension, and you might be able to carry over unused allowance from the previous 3 tax years.

So a deposit into a cash ISA on 5 April 2027 uses your 2026/27 allowance, and one made a day later uses 2027/28's, when the lower cash limit applies to under-65s.

Tax weeks and tax months start on 6 April too

Tax week 1 runs from 6 to 12 April, and each tax month runs from the 6th of one month to the 5th of the next. The Income Tax (PAYE) Regulations 2003 define these periods and also define tax quarters of 6 April to 5 July, 6 July to 5 October, 6 October to 5 January and 6 January to 5 April. Payroll uses them to apply your tax code week by week or month by month.

A tax year of 365 days has 52 full weeks and one extra day, so the regulations create a short "Week 53": just the last day of the tax year, or the last 2 days in a leap year. In 2026/27, week 53 is Monday 5 April 2027, so someone paid weekly on Mondays gets 53 paydays in the year. In 2027/28, which includes 29 February 2028, week 53 is 4 and 5 April 2028.

On 28 September 2026 it is tax week 26 and tax month 6. The what week is it page shows today's tax week and month.

Scottish and Welsh Income Tax use the same tax year

Scottish and Welsh Income Tax rates apply to the same 6 April to 5 April tax year as the rest of the UK. According to GOV.UK, the 2026/27 Scottish rates of 19%, 20%, 21%, 42%, 45% and 48% apply to wages, pensions and most other income, while dividends and savings interest are taxed at UK rates.

Wales uses the same bands as England and Northern Ireland in 2026/27. GOV.UK says you pay Welsh rates if you live in Wales for longer than anywhere else in the UK during a tax year (6 April to 5 April the following year), and if you move, the new rates are backdated to the start of that tax year. National Insurance is the same across the whole UK.

Council Tax is different: it runs on a financial year of 12 months beginning on 1 April, under section 116 of the Local Government Finance Act 1992. That is why a new Council Tax bill starts on 1 April, five days before the new tax year.

Companies use a financial year from 1 April to 31 March

Corporation Tax is charged by financial years running from 1 April to 31 March, while each company files for its own accounting period, which can end on any date. The Interpretation Act 1978 defines the financial year for central taxes as the 12 months ending with 31 March, and GOV.UK's Corporation Tax rates page works out tax by financial years starting on 1 April.

A company's accounting period is normally the same as the financial year covered by its annual accounts and cannot be longer than 12 months, according to GOV.UK. Where rates change part-way through, you split the profit by days. The main rate is 25% and the small profits rate 19% for profits of £50,000 or less, and Budget 2025 said both rates stay the same for the financial year beginning 1 April 2027.

Example. For a company with an accounting period of 1 January to 31 December 2026 and taxable profits up to £1.5 million, Corporation Tax is due 9 months and 1 day after the period ends, on 1 October 2027, and the Company Tax Return is due 12 months after, on 31 December 2027. Work out the bill with the Corporation Tax calculator.

What's new for tax year 2027/28

The 2027/28 tax year starts on 6 April 2027 with several changes announced at Budget 2025, according to HM Treasury's overview of tax legislation and rates (updated 5 December 2025):

• Savings income: the savings basic, higher and additional rates rise by 2 percentage points to 22%, 42% and 47% from 6 April 2027.
• Property income: separate property income rates of 22%, 42% and 47% apply in England, Wales and Northern Ireland from 6 April 2027.
• Cash ISAs: the cash ISA limit becomes £12,000 for savers under 65, within the £20,000 overall limit.
• Pensions and Inheritance Tax: unused pension funds and death benefits come into the estate for Inheritance Tax from 6 April 2027.
• Making Tax Digital: sole traders and landlords with qualifying income over £30,000 in 2025/26 must start from 6 April 2027, according to GOV.UK.

The Personal Allowance of £12,570 and the higher rate threshold of £50,270 stay the same in 2027/28, and Budget 2025 keeps the main National Insurance thresholds at their current levels until April 2031.

What to do before the tax year ends on 5 April 2027

1. If you need to register for Self Assessment for 2025/26, do it by 5 October 2026, then file online by 31 January 2027.
2. Decide how much of your £20,000 ISA allowance to use by 5 April 2027. If you are under 65 and save in cash, this is the last tax year with a £20,000 cash ISA limit.
3. Check how much pension annual allowance you have left for 2026/27, including any unused allowance from the previous 3 tax years.
4. If you are self-employed, set aside money for 31 January and 31 July, and check whether Making Tax Digital applies to you from 6 April 2027.
5. Check your P60 when it arrives by 31 May 2027 against your last payslip, and run your pay through the take-home pay calculator to spot a wrong tax code early.