UK Tax Deadlines 2026/27: Key HMRC Dates

Which UK Tax Year Are These Dates For?

The UK personal tax year runs from 6 April to 5 April of the following calendar year. The 2026/27 tax year runs from 6 April 2026 to 5 April 2027. A Self Assessment tax return filed during the 2026/27 tax year relates to income and capital gains earned during the previous tax year (6 April 2025 to 5 April 2026). This one-year lag is why major Self Assessment deadlines for the 2025/26 tax year fall in October 2026 and January 2027. In contrast, commercial business taxes such as Corporation Tax and VAT operate on company accounting periods or quarterly VAT accounting periods rather than the statutory 6 April personal tax year.

Self Assessment Tax Deadlines (Filing, Balancing & Payments on Account)

Self Assessment deadlines are determined by the tax year, the method used to submit the return (paper vs online), and whether advance payments on account apply to your account. First-time filers must notify HMRC and register by 5 October 2026 for the 2025/26 tax year. If you miss this registration deadline, HMRC allows 3 months from the date of their response letter or notice to file, but your tax bill must still be cleared by 31 January 2027 to avoid late-payment interest. Payments on account are advance payments toward your next tax bill. Each payment equals 50% of your previous year's tax liability (excluding Capital Gains Tax and student loans). They fall due on 31 January and 31 July. If your tax bill was under £1,000 or over 80% of your tax was deducted at source via PAYE, payments on account do not apply.

Corporation Tax & Company Tax Return Deadlines

Corporation Tax deadlines are calculated relative to your limited company's accounting period rather than a fixed calendar day. For most small and medium companies (taxable profits up to £1.5 million), Corporation Tax must be paid 9 months and 1 day after the accounting period ends. Crucially, the Company Tax Return (CT600) filing deadline is later: it is due 12 months after the accounting period ends. Therefore, you must pay your Corporation Tax before you submit the final return. Large companies with taxable profits exceeding £1.5 million must pay Corporation Tax in quarterly instalments starting halfway through the accounting period itself. Associated companies share this £1.5 million threshold, which reduces accordingly (e.g. £750,000 each for two associated companies).

VAT Return & Payment Deadlines (Making Tax Digital)

Most VAT-registered UK businesses operate on quarterly accounting cycles. The deadline to submit your VAT Return and ensure payment clears HMRC's account is strictly one calendar month and 7 days after the end of your VAT accounting period. Under Making Tax Digital (MTD) for VAT rules, all VAT-registered entities must maintain digital records and submit returns using MTD-compatible software. The statutory deadline applies even if your business has no VAT to pay or reclaim for that quarter (a 'nil return'). Unlike paper forms, the 1-month-and-7-day deadline applies regardless of whether the date falls on a weekend or bank holiday. If paying by Direct Debit, HMRC normally collects funds around 3 working days after the submission date, but businesses must set up the mandate in advance.

PAYE, Payroll & Employer Real Time Information (RTI)

Employers deducting Income Tax, student loan repayments, and Class 1 National Insurance from employee wages must report and remit deductions on strict monthly or quarterly timetables. Under Real Time Information (RTI), a Full Payment Submission (FPS) must be sent to HMRC on or before the employees' payday. The physical payment of PAYE and National Insurance must reach HMRC by the 22nd of the following tax month if paying electronically (or by the 19th if paying by postal cheque). Small employers whose average monthly payments are under £1,500 can request permission from HMRC to pay quarterly, with payment due on the 22nd of the month following the end of the calendar quarter (e.g. 22 July, 22 October, 22 January, 22 April).

P11D, P11D(b) & Class 1A National Insurance Deadlines

Employers providing taxable benefits in kind (such as company cars, private medical insurance, or director interest-free loans) face annual reporting and payment obligations following the tax year end on 5 April. Employers must submit form P11D for each relevant employee and form P11D(b) declaring total Class 1A National Insurance contributions to HMRC by 6 July 2027 (for the 2026/27 tax year). Employees must also be provided with copies of their P11D statements by 6 July. Payment of Class 1A National Insurance on benefits must reach HMRC by 22 July 2027 if paying electronically (or 19 July if paying by cheque). Under a PAYE Settlement Agreement (PSA), the final payment deadline is 22 October electronically (19 October by post).

Capital Gains Tax (CGT) Deadlines & 60-Day Residential Property Rule

Capital Gains Tax deadlines differ substantially between UK residential property sales and disposals of other capital assets (such as shares, crypto assets, or commercial property). If you sell or dispose of a UK residential property that incurs a taxable gain (e.g. buy-to-let, second home, or inherited property not covered by Private Residence Relief), you must report the gain and pay the estimated Capital Gains Tax to HMRC within 60 days of completion. This 60-day residential property requirement is completely separate from annual Self Assessment. Missing the 60-day window triggers an immediate £100 penalty plus interest. For other capital assets, gains are declared on your annual Self Assessment return (SA108) by 31 January following the tax year end, or via HMRC's 'real-time' Capital Gains Tax service by 31 December.

Companies House Accounts vs HMRC Tax Deadlines Comparison

Many company directors confuse Companies House filing deadlines with HMRC Corporation Tax deadlines. These two government bodies operate under different statutory frameworks with distinct due dates. For private limited companies, statutory annual accounts must be delivered to Companies House within 9 months of the financial year end. In contrast, Corporation Tax payment to HMRC is due 9 months and 1 day after the accounting period end, while the actual Company Tax Return (CT600) is not due to HMRC until 12 months after the period end.

UK Tax Deadline Master Calendar (Chronological Schedule)

Use this chronological master timetable to track key HMRC statutory filing and payment dates across the 2026/27 compliance cycle.

Payment Timing, HMRC Processing Times & Banking Clearance Rules

A statutory HMRC payment deadline means cleared funds must arrive in HMRC's bank account by the specified date. Initiating a payment on the deadline day using a slow transfer method can cause your payment to arrive late, generating automatic interest charges and late-payment penalties. Different payment methods carry different processing times: • Faster Payments & Online Card: Arrives same day or next day. • CHAPS: Same working day if initiated within banking cut-off. • Bacs & Direct Debit: Typically takes 3 working days to clear. • Standing Order: Around 3 working days. • Postal Cheque: Allow at least 3 working days for postage plus 3 working days for cheque clearing. Always quote your correct 10-digit Unique Taxpayer Reference (UTR) ending in 'K' for Self Assessment, or your 17-character Corporation Tax payment reference to prevent misallocation.

Late Filing Penalties, HMRC Interest & Reasonable Excuses

Failing to meet HMRC filing or payment deadlines incurs automatic statutory penalties and compounding interest. For Self Assessment: • 1 day late: Immediate £100 fixed penalty (even if zero tax is owed). • 3 months late: Daily penalties of £10 per day for up to 90 days (max £900). • 6 months late: Further penalty of 5% of tax due or £300 (whichever is greater). • 12 months late: Additional penalty of 5% or £300 (up to 100% of tax for deliberate concealment). Late payments also incur HMRC late payment interest (currently set at Bank of England base rate + 2.5%, equaling 7.75% in 2026), plus 5% surcharges on tax unpaid after 30 days, 6 months, and 12 months. Taxpayers can appeal penalties if they have a 'reasonable excuse' (such as unexpected hospitalisation, bereavement, severe postal delays, or systemic HMRC online service failure). Financial hardship is not accepted as a reasonable excuse for failing to submit returns on time.

Action Plan: How to Build a Tax Deadline Schedule & Avoid Common Mistakes

Avoid costly penalties by implementing a proactive 6-step compliance system: 1. Classify all relevant taxes (personal income, business profits, VAT, employer payroll, property gains). 2. Note your specific financial period ends (5 April for personal, bespoke dates for limited company and VAT). 3. Differentiate between return filing dates and tax payment dates. 4. Establish internal preparation cut-offs 3 weeks ahead of statutory HMRC deadlines. 5. Check whether advance payments on account or quarterly instalments apply. 6. Verify exact balances and reference numbers in your HMRC online business tax account before transferring funds.

Frequently Asked Questions (6)