Tax Year 2026/27: Key Dates
The UK tax year runs from 6 April 2026 to 5 April 2027. Most of these deadlines are fixed, and HMRC does not care that you forgot.
Self Assessment
| Date | Deadline | |------|----------| | 5 October 2026 | Register for Self Assessment (if new) | | 31 October 2026 | Paper tax return deadline | | 31 January 2027 | Online tax return deadline | | 31 January 2027 | Pay tax owed for 2025/26 | | 31 January 2027 | First payment on account for 2026/27 | | 31 July 2027 | Second payment on account for 2026/27 |
31 January is the one that catches people out. You owe both the balancing payment for the year just gone and the first payment on account for the current year, on the same day. That is a large combined sum if you have not budgeted for it separately.
Penalties for late filing: - 1 day late: £100 automatic penalty - 3 months late: £10/day (up to £900) - 6 months late: 5% of tax due or £300 (whichever is greater) - 12 months late: up to 100% of tax due
The £100 penalty applies even if you owe no tax at all. There is no discretion, so file on time.
VAT Quarters (Standard)
| Quarter ending | Deadline (return + payment) | |----------------|---------------------------| | 30 June 2026 | 7 August 2026 | | 30 September 2026 | 7 November 2026 | | 31 December 2026 | 7 February 2027 | | 31 March 2027 | 7 May 2027 |
These are the standard quarterly dates. Your actual quarters depend on when you registered, so check your VAT certificate if you are unsure which stagger you are on.
Corporation Tax
- Payment: 9 months and 1 day after your accounting period ends
- Return: 12 months after your accounting period ends
These dates are tied to your company's accounting period, not the tax year, so they vary by business. A company with a 31 March year-end owes payment by 1 January and must file its return by 31 March the following year.
Companies House
- Annual accounts: 9 months after year-end (private company)
- Confirmation statement: Every 12 months from incorporation date
Companies House and HMRC are separate. Filing your accounts with one does not file with the other.
ISA & Pension Allowances
| Allowance | 2026/27 | |-----------|---------| | ISA allowance | £20,000 | | Pension annual allowance | £60,000 | | Capital Gains Tax allowance | £3,000 | | Dividend allowance | £500 (was £1,000 in 2023/24) | | Personal Allowance | £12,570 |
The CGT allowance has been cut hard in recent years. At £3,000 it does not take large gains before tax kicks in. If you hold investments in a general account, realise gains in a controlled way across tax years rather than letting them accumulate into one taxable lump.
Bank Holidays 2026/27
Not tax deadlines, but HMRC and banks are closed: - 25 December 2026 (Christmas) - 28 December 2026 (Boxing Day substitute) - 1 January 2027 (New Year's Day) - 29 March 2027 (Good Friday) - 1 April 2027 (Easter Monday)
If a deadline falls on a bank holiday, the practical deadline moves to the last working day before it. Do not leave it until the final day and assume BACS will clear in time.
One Practical Step
Add every date above to a calendar now, with a reminder two weeks before each one. That buys you time to find documents and chase an accountant before the deadline instead of on the day. Scrambling on 30 January is avoidable. Use CoreFi's financial calendar to track these automatically alongside your other financial dates.