UK Tax Deadlines 2025/26
Complete HMRC calendar with live countdowns. Self Assessment, VAT, PAYE, P11D, Corporation Tax — never miss a deadline.
Last reviewed: 6 April 2026 by Mustafa Bilgic, UK Tax Specialist
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Complete UK Tax Deadlines Guide 2025/26
HMRC enforces strict deadlines for tax filings and payments. Missing them triggers automatic penalties — £100 instantly for Self Assessment, daily fines after three months, and 7.75% interest on unpaid tax. This page lists every key 2025/26 and 2026 deadline with a live countdown so you can plan ahead.
Self Assessment — the big two
If you're self-employed, a landlord, a high earner (£100k+), or have untaxed income, you need to file a Self Assessment tax return.
- 31 October 2025 — Paper return deadline for the 2024/25 tax year (most people now file online).
- 31 January 2026 — Online filing deadline AND balancing payment for 2024/25 AND first payment on account for 2025/26. This is the most important UK tax date.
- 31 July 2026 — Second payment on account for 2025/26.
Late filing penalties stack quickly: £100 instant, then £10/day after 3 months (max £900), then 5% of tax or £300 (whichever is greater) at 6 and 12 months. Use our Tax Calculator to check what you owe before filing.
PAYE and employer deadlines
If you run payroll for staff (or yourself as a director), the employer calendar is unforgiving:
- By 19 April 2026 — Final FPS submission for 2025/26 tax year.
- By 31 May 2026 — P60s issued to all staff still on payroll on 5 April.
- By 6 July 2026 — P11D and P11D(b) submission for benefits in kind.
- By 22 July 2026 — Class 1A NIC payment (electronic) on benefits in kind.
VAT — Making Tax Digital is mandatory
All VAT-registered businesses must use MTD-compatible software. Quarterly returns and payments are due 1 month and 7 days after the period ends. For calendar quarters: Q1 due 7 May, Q2 due 7 August, Q3 due 7 November, Q4 due 7 February. Direct Debit gets you an extra 3 working days for payment.
Corporation Tax
Companies pay Corporation Tax 9 months and 1 day after the accounting period ends. The CT600 return must be filed within 12 months. So a December 2025 year-end means CT payment by 1 October 2026 and filing by 31 December 2026. Large companies (profits over £1.5m) pay in quarterly instalments.
Capital Gains Tax — 60-day rule
If you sell UK residential property and owe CGT, you must report it and pay within 60 days of completion via the UK Property Reporting Service. This is separate from your annual Self Assessment and applies even if your sale isn't liable to tax (no submission needed if no tax due).
End of tax year — 5 April 2026
Use it or lose it. The 2025/26 tax year ends on 5 April 2026 and the new year starts 6 April 2026. Before 5 April, max out:
- £20,000 ISA allowance — Cash, Stocks & Shares, Innovative Finance, Lifetime ISA combined
- £60,000 pension annual allowance (or 100% of earnings if lower; tapered for high earners over £260k)
- £3,000 CGT exempt amount (down from £6,000 in 2023/24)
- £500 dividend allowance
- £1,000 personal savings allowance (basic rate; £500 higher rate; £0 additional rate)
Penalty interest rates 2025/26
HMRC late payment interest is Bank of England base rate + 2.5%. As of April 2026 the base rate is 5.25%, so HMRC interest is 7.75% on unpaid tax. Repayment interest (when HMRC owes you) is base rate − 1%, currently 4.25% — a 3.5 percentage point gap that strongly favours HMRC.
Add to your calendar
Each deadline above has an "Add to Calendar" button that downloads a standard .ics file compatible with Google Calendar, Apple Calendar, Outlook and any CalDAV client. You can also set HMRC SMS/email reminders via your Personal Tax Account.
Related calculators
Frequently asked questions
What is the Self Assessment deadline for 2024/25?
Online filing for 2024/25 must be done by midnight on 31 January 2026. Paper returns by 31 October 2025. Both your 2024/25 balancing payment and 2025/26 first payment on account are also due 31 January 2026. £100 instant penalty for missing the online deadline.
When is the second payment on account due?
31 July 2026 for the 2025/26 tax year. Each payment is normally half your previous year's total tax bill. Apply via SA303 or your Personal Tax Account to reduce if your income has dropped.
What are the VAT return deadlines for 2026?
Quarterly returns and payments are due 1 month + 7 days after the period ends. Calendar quarters: Q1 (Jan–Mar) due 7 May; Q2 (Apr–Jun) due 7 August; Q3 (Jul–Sep) due 7 November; Q4 (Oct–Dec) due 7 February. Direct Debit gives you an extra 3 working days.
When are P11D and P60 forms due?
P60s to employees by 31 May. P11D and P11D(b) filed with HMRC by 6 July. Class 1A NIC paid by 22 July (electronic) or 19 July (postal cheque).
What is the Corporation Tax filing deadline?
CT600 within 12 months of accounting period end (e.g. Dec 2025 year-end → file by 31 Dec 2026). CT payment is earlier — 9 months + 1 day after year-end (1 Oct 2026 for Dec 2025 year-end). Large companies pay in quarterly instalments.
What happens if I miss a Self Assessment deadline?
£100 instant fine for being 1 day late. After 3 months: daily £10 fines up to £900. After 6 months: 5% of tax or £300 (whichever is greater). After 12 months: another 5% or £300. Late payment interest is 7.75%. You can appeal with a reasonable excuse.