UK Tax Deadlines Every Small Business Must Know 2026

Essential Tax Calendar for 2026/27 Tax Year | Complete Guide for UK Small Businesses

Understanding the UK Tax Year Calendar

The UK tax system operates on a unique calendar that doesn't align with the standard calendar year. Understanding these periods is fundamental to meeting your tax obligations.

Key Tax Periods You Need to Know

Income Tax and Self Assessment Tax Year: Runs from 6 April to 5 April the following year. The 2025/26 tax year begins on 6 April 2025 and ends on 5 April 2026. The 2026/27 tax year will run from 6 April 2026 to 5 April 2027.

Corporation Tax Accounting Period: Can align with your company's financial year, which you choose when incorporating. Most businesses select a 12-month period ending on a specific date. Your Corporation Tax deadline is 12 months after your accounting period ends.

VAT Quarters: Standard VAT quarters run March/June/September/December, but you can choose different periods when registering. Your VAT return is due one month and seven days after your quarter ends.

PAYE Tax Month and Quarter: Runs from the 6th of one month to the 5th of the next. PAYE tax months are numbered 1 to 12, with Month 1 running 6 April to 5 May.

Why These Dates Matter for Your Business

Unlike employees who have tax deducted automatically through PAYE, small business owners are responsible for calculating, reporting, and paying their own tax. Missing deadlines triggers an automatic penalty structure that can quickly escalate into thousands of pounds, even if you ultimately owe no tax.

HMRC receives over 12 million Self Assessment returns annually, and approximately 800,000 people miss the January deadline each year, resulting in automatic £100 penalties. Don't be one of them.

Self Assessment Tax Deadlines 2026

Self Assessment is the system HMRC uses to collect Income Tax from sole traders, partners, landlords, and anyone with untaxed income. Here are the critical dates for the 2025/26 tax year.

Registration and Filing Deadlines

What Happens If You File Late

The penalty structure for late Self Assessment returns is severe and automatic:

• 1 day late: £100 immediate penalty (even if you owe no tax)
• 3 months late: Additional £10 per day for up to 90 days (maximum £900)
• 6 months late: Further penalty of 5% of tax owed or £300, whichever is greater
• 12 months late: Another 5% of tax owed or £300, whichever is greater, plus potential investigation for deliberate withholding

Corporation Tax Filing Deadlines

Limited companies must file a Corporation Tax return (CT600) and pay any Corporation Tax owed. The deadlines are based on your company's accounting period end date.

Corporation Tax Return Deadline

Filing deadline: 12 months after your accounting period ends. For example, if your accounting period ended on 31 March 2026, your CT600 must be filed by 31 March 2027.

Payment deadline: 9 months and 1 day after your accounting period ends. Using the same example, Corporation Tax is due by 1 January 2027.

Important Considerations for 2026

The Corporation Tax rate for the financial year beginning 1 April 2025 is:

• 19% for companies with profits up to £50,000 (small profits rate)
• 25% for companies with profits over £250,000 (main rate)
• Marginal relief applies between £50,000 and £250,000, creating an effective rate between 19% and 25%

Quarterly Instalment Payments

Large companies (those with profits exceeding £1.5 million) must pay Corporation Tax in quarterly instalments rather than a single annual payment. The instalments are due in months 7, 10, 13, and 16 of the accounting period.

Very large companies (profits over £20 million) have an accelerated payment schedule, paying in months 3, 6, 9, and 12 plus a final adjustment in month 13.

VAT Return Deadlines and Payment Dates 2026

VAT-registered businesses must submit regular VAT returns and pay any VAT owed to HMRC. The frequency depends on your turnover and the scheme you're on.

Standard VAT Quarter Deadlines

If you're on the standard quarterly VAT scheme, your returns and payments are due one month and seven days after each quarter ends.

VAT Quarter Ending	Filing & Payment Deadline
31 January 2026	7 March 2026
30 April 2026	7 June 2026
31 July 2026	7 September 2026
31 October 2026	7 December 2026

Alternative VAT Schemes and Deadlines

Important: The VAT registration threshold will remain at £90,000 for 2026 (confirmed in Autumn Budget 2025). The deregistration threshold remains at £88,000.

Monthly VAT Returns: Due one month and seven days after each month ends. Typically used by businesses in the VAT repayment position or those who voluntarily opt in.

Annual Accounting Scheme: Submit one VAT return per year, two months after your VAT year ends. Make advance payments throughout the year (either 9 monthly or 3 quarterly instalments).

Cash Accounting Scheme: Available for businesses with turnover up to £1.35 million. You account for VAT when you receive payment, not when you issue the invoice. Same quarterly deadlines apply.

Making Tax Digital for VAT

All VAT-registered businesses must use Making Tax Digital (MTD) compatible software to keep digital records and submit VAT returns. This has been mandatory since April 2022.

What you must do:

• Keep digital VAT records using MTD-compatible software
• Submit your VAT return digitally through the software
• Maintain a digital audit trail linking your records to your VAT return

Failure to comply with MTD requirements can result in penalties, though HMRC applies a "soft landing" approach for genuine mistakes during the transition period.

PAYE and Payroll Deadlines

If you employ staff (including yourself as a director), you must operate PAYE and make regular submissions and payments to HMRC.

Monthly PAYE Obligations

Full Payment Submission (FPS): Must be submitted on or before each payday. This reports employees' pay and deductions for each pay period.

PAYE Payment Deadline: 22nd of each month for electronic payments (19th if paying by cheque, though this is increasingly rare). This covers the tax month ending on the 5th of that month.

For example, for the tax month ending 5 February 2026, PAYE payment is due by 22 February 2026.

Annual PAYE Deadlines

Deadline	Requirement
19 April 2026	Final PAYE payment for 2025/26 tax year if paying by post (22 April if electronic)
19 May 2026	Submit Employer Payment Summary (EPS) for 2025/26 if you claimed Employment Allowance or other deductions
31 May 2026	Provide employees with P60 forms showing total pay and deductions for 2025/26
6 July 2026	Submit P11D forms reporting benefits and expenses provided to employees and directors during 2025/26
6 July 2026	Submit P11D(b) form declaring Class 1A National Insurance on benefits in kind
22 July 2026	Pay Class 1A National Insurance on benefits in kind (19 July if by post)

Real Time Information (RTI) Compliance

HMRC's Real Time Information system requires you to report payroll information every time you pay employees. Late or incorrect submissions can result in penalties.

Penalty structure for late FPS submissions:

• 1-9 employees: £100 per month for each late submission
• 10-49 employees: £200 per month
• 50-249 employees: £300 per month
• 250+ employees: £400 per month

The penalty is charged per month, so multiple late submissions in one tax month count as one penalty. HMRC does offer an annual grace period for one late submission per tax year for small employers.

Capital Gains Tax Reporting Deadlines

Capital Gains Tax (CGT) rules changed significantly in recent years, with specific deadlines for reporting and paying tax on asset disposals.

Residential Property Disposals

If you sell UK residential property that isn't your main home (buy-to-let, second homes, inherited property), you must report and pay any CGT due within 60 days of completion.

This is done through the UK Property Disposal Return system. The 60-day deadline is strict, and late reporting results in penalties even if no tax is ultimately due.

Other Asset Disposals

For other chargeable assets (shares, business assets, commercial property, cryptocurrency), Capital Gains Tax is reported through your Self Assessment tax return with the standard 31 January deadline.

However, if you sell assets and realize significant gains, you may want to make payments on account earlier to reduce your tax bill on 31 January.

CGT Annual Exempt Amount

For the 2025/26 tax year, the Capital Gains Tax annual exempt amount is £3,000. This is the amount of gains you can make tax-free each year. Any gains above this threshold are taxable at 18% (basic rate) or 24% (higher rate) for residential property, and 10% or 20% for other assets.

Married couples and civil partners each get their own £3,000 allowance, making tax-efficient asset transfer strategies valuable for CGT planning.

Companies House Filing Requirements

All UK limited companies must file annual accounts and a Confirmation Statement with Companies House, separate from their tax obligations to HMRC.

Annual Accounts Deadline

Private limited companies must file their annual accounts within 9 months of their accounting reference date (year-end).

For example, if your company's year-end is 31 March 2026, your accounts must be filed with Companies House by 31 December 2026.

First accounts exception: Newly incorporated companies get up to 21 months from their incorporation date to file their first accounts, giving extra time to establish accounting systems.

Confirmation Statement Deadline

Every company must file a Confirmation Statement at least once every 12 months. This confirms company details such as registered office address, directors, shareholders, and share capital are correct.

The deadline is 14 days after the "confirmation date" (usually the anniversary of incorporation or last Confirmation Statement).

Penalties for Late Companies House Filings

Late accounts penalties:

How Late?	Private Company Penalty
Up to 1 month	£150
1-3 months	£375
3-6 months	£750
Over 6 months	£1,500

These penalties double for repeat offenses within 12 months. Persistent failure to file can result in director disqualification and company strike-off.

Late Confirmation Statement penalty: £150, increasing significantly for continued failure to file.

Construction Industry Scheme (CIS) Deadlines

If you're a contractor in the construction industry, you must operate the Construction Industry Scheme and make regular returns and payments to HMRC.

Monthly CIS Obligations

CIS Return Deadline: 19th of each month following the tax month end (14th if filing on paper, though online filing is now mandatory for most).

For example, for the CIS month ending 5 February 2026, the return must be filed by 19 February 2026.

CIS Payment Deadline: 22nd of each month (19th if paying by post). This covers deductions made from subcontractors during the previous tax month.

Verification Requirements

Before paying a new subcontractor, you must verify them with HMRC. This can be done online through the CIS online service and must be completed before the first payment.

HMRC will tell you:

• Whether the subcontractor is registered for CIS
• What deduction rate to apply (0%, 20%, or 30%)
• Their verification number (keep this for your records)

CIS Penalties

Late CIS returns incur automatic penalties:

• 1-9 subcontractors: £100 per month
• 10-49 subcontractors: £200 per month
• 50-249 subcontractors: £300 per month
• 250+ subcontractors: £400 per month

Interest is charged on late CIS payments at the same rate as other HMRC late payments (currently over 7%).

Making Tax Digital Compliance Dates

Making Tax Digital (MTD) is HMRC's program to digitize the UK tax system. Different aspects of MTD have different compliance dates.

MTD for VAT (Already Mandatory)

All VAT-registered businesses have been required to use MTD-compatible software since April 2022. If you're not yet compliant, you're already facing potential penalties.

MTD for Income Tax (Upcoming)

Implementation date: 6 April 2026 for self-employed individuals and landlords with qualifying income over £50,000.

From this date, if your self-employment or property income exceeds £50,000, you must:

• Keep digital records using compatible software
• Submit quarterly updates to HMRC (not full tax calculations)
• Submit a final annual declaration
• Continue to submit a Self Assessment tax return (initially)

Quarterly update deadlines for 2026/27:

• Q1 (6 April - 5 July 2026): Due 7 August 2026
• Q2 (6 July - 5 October 2026): Due 7 November 2026
• Q3 (6 October 2026 - 5 January 2027): Due 7 February 2027
• Q4 (6 January - 5 April 2027): Due 7 May 2027

Final declaration deadline: 31 January 2028 (for the 2026/27 tax year)

Preparing for MTD for Income Tax

Even if you're under the £50,000 threshold, now is the time to transition to digital record-keeping. Cloud accounting software like Xero, QuickBooks, FreeAgent, or Sage is compatible with MTD and makes quarterly reporting straightforward.

Future threshold reductions:

• April 2027: Threshold drops to £30,000
• April 2028: Threshold drops to £20,000

The threshold will gradually reduce to include more taxpayers, so early adoption gives you time to establish good digital habits without deadline pressure.

Penalty Framework: What Late Filing Costs You

Understanding HMRC's penalty structure helps you prioritize compliance and understand the true cost of missing deadlines.

Late Filing Penalties Summary

Tax Type	Initial Penalty	Escalation
Self Assessment	£100 (1 day late)	£10/day after 3 months, then 5% of tax at 6 and 12 months
Corporation Tax	No fixed penalty	Interest charged daily on late payment at ~7.25%
VAT Return	Default surcharge at 2%	Increases to 5%, 10%, then 15% for repeated defaults
PAYE (1-9 employees)	£100 per month	Increases with number of employees
Companies House Accounts	£150 (up to 1 month late)	£375, £750, £1,500 at longer delays
CIS Return	£100 per month (1-9 subcontractors)	Increases with number of subcontractors

Interest on Late Payments

Interest accrues on all late tax payments from the day after the deadline until payment is received. The current HMRC interest rate is Bank of England base rate plus 2.5%, currently around 7.25% per year.

This compounds daily, meaning a £10,000 late tax payment costs approximately £2 per day in interest.

Reasonable Excuse Appeals

HMRC may cancel penalties if you had a "reasonable excuse" for late filing or payment. Acceptable excuses include:

• Serious illness or bereavement
• Unexpected hospital admission
• Computer or software failure (if you tried to file in good time)
• Fire, flood, or theft affecting your records
• Postal delays (for paper submissions attempted well in advance)

Financial difficulties, reliance on someone else, or being too busy are generally not accepted as reasonable excuses.

To appeal a penalty, you must do so within 30 days of the penalty notice. Submit your appeal through your HMRC online account or in writing to the address on the penalty letter.

Your Annual Tax Deadlines Calendar 2026

Here's a month-by-month breakdown of key tax deadlines to help you plan your compliance activities throughout 2026.

January 2026

19 January: CIS return and payment for December 2025 tax month

22 January: PAYE payment for December 2025 tax month

31 January:

• Self Assessment tax return for 2024/25 tax year
• Payment of any tax owed for 2024/25
• First payment on account for 2025/26 (if applicable)

February 2026

7 February: VAT return and payment for quarter ending 31 December 2025

19 February: CIS return and payment for January 2026 tax month

22 February: PAYE payment for January 2026 tax month

March 2026

7 March: VAT return and payment for quarter ending 31 January 2026

19 March: CIS return and payment for February 2026 tax month

22 March: PAYE payment for February 2026 tax month

31 March: Common accounting year-end for many limited companies (Corporation Tax due 1 January 2027, accounts due 31 December 2026)

April 2026

5 April: End of 2025/26 tax year

6 April:

• Start of 2026/27 tax year
• MTD for Income Tax begins for those with qualifying income over £50,000

19 April: Final PAYE payment for 2025/26 tax year (if paying by post; 22 April for electronic)

19 April: CIS return and payment for March 2026 tax month

May 2026

19 May:

• Employer Payment Summary (EPS) for 2025/26 if you claimed deductions
• CIS return and payment for April 2026 tax month

22 May: PAYE payment for April 2026 tax month

31 May: Provide P60s to all employees for 2025/26 tax year

June 2026

7 June: VAT return and payment for quarter ending 30 April 2026

19 June: CIS return and payment for May 2026 tax month

22 June: PAYE payment for May 2026 tax month

July 2026

6 July:

• Submit P11D forms for benefits in kind provided in 2025/26
• Submit P11D(b) declaring Class 1A National Insurance on benefits

19 July: CIS return and payment for June 2026 tax month

22 July:

• PAYE payment for June 2026 tax month
• Payment of Class 1A National Insurance on benefits in kind (19 July if by post)

31 July: Second payment on account for 2025/26 tax year (if applicable)

August 2026

7 August: MTD for Income Tax Q1 update deadline (for those in MTD, covering 6 April - 5 July 2026)

19 August: CIS return and payment for July 2026 tax month

22 August: PAYE payment for July 2026 tax month

September 2026

7 September: VAT return and payment for quarter ending 31 July 2026

19 September: CIS return and payment for August 2026 tax month

22 September: PAYE payment for August 2026 tax month

October 2026

5 October: Register for Self Assessment if you need to complete a return for 2025/26

19 October: CIS return and payment for September 2026 tax month

22 October: PAYE payment for September 2026 tax month

31 October: Paper Self Assessment deadline for 2025/26 tax year

November 2026

7 November: MTD for Income Tax Q2 update deadline (for those in MTD, covering 6 July - 5 October 2026)

19 November: CIS return and payment for October 2026 tax month

22 November: PAYE payment for October 2026 tax month

December 2026

7 December: VAT return and payment for quarter ending 31 October 2026

19 December: CIS return and payment for November 2026 tax month

22 December: PAYE payment for November 2026 tax month

30 December: File Self Assessment online by this date to have tax collected through PAYE code (if owe less than £3,000)

Essential Deadline Management Strategies

Set Up Calendar Reminders

Add all relevant tax deadlines to your business calendar with reminders at least one week in advance. Digital calendars allow recurring annual reminders that automatically adjust for weekends and bank holidays.

Use Accounting Software

Modern cloud accounting software (Xero, QuickBooks, FreeAgent, Sage) includes built-in deadline tracking and can automatically prepare and submit many returns. This reduces manual work and missed deadlines.

Maintain a Compliance Checklist

Create a monthly compliance checklist covering all your tax obligations. Tick off each task as completed to maintain a clear audit trail.

File and Pay Early

Aim to file returns at least a week before deadlines. This gives you buffer time for technical issues, unexpected queries, or missing information. Early filing also means early certainty about tax liabilities.

Set Up Payment Plans

For Self Assessment, consider HMRC's Budget Payment Plan allowing you to spread payments throughout the year rather than facing a large January bill. For other taxes, ensure you have funds set aside well in advance.

Hire Professional Support

For businesses with complex affairs or multiple obligations, a qualified accountant or tax advisor can manage compliance, ensure you claim all available reliefs, and provide peace of mind. Their fees are tax-deductible business expenses.

Common Questions About Tax Deadlines

What if a deadline falls on a weekend or bank holiday?

When a tax deadline falls on a weekend or bank holiday, it automatically extends to the next working day. However, don't rely on this - aim to file early to avoid last-minute technical issues.

Can I get an extension on tax deadlines?

HMRC rarely grants extensions except in exceptional circumstances (serious illness, natural disaster, bereavement). Financial difficulties or being too busy are not acceptable reasons. The best approach is to file on time, even if you can't pay in full, then arrange a Time to Pay agreement.

What should I do if I've already missed a deadline?

File or pay immediately to minimize penalties. The longer you wait, the more the penalties escalate. If you had a reasonable excuse, submit an appeal within 30 days of the penalty notice. Consider whether you can claim reasonable excuse status.

How can I check what I've already filed with HMRC?

Log into your HMRC online account to view all submitted returns, payment history, and upcoming obligations. Your account shows confirmation of receipt for all electronic submissions.

Do deadlines differ between England, Scotland, Wales, and Northern Ireland?

No. HMRC tax deadlines are the same across the entire UK. However, Scottish taxpayers have different income tax rates and bands, which affects the amount of tax owed, not the deadlines.

Free Tools to Help You Meet Deadlines

Managing multiple tax deadlines becomes much easier with the right tools. Our website offers free calculators to help you estimate your tax liabilities and plan ahead:

Available Free Calculators

• Self Assessment Tax Calculator: Estimate your income tax and National Insurance liability before filing
• Corporation Tax Calculator: Calculate your company's tax bill including marginal relief
• VAT Calculator: Quick VAT calculations for pricing and return preparation
• CIS Tax Calculator: Work out deductions for contractors and subcontractors
• HMRC Penalty Calculator: Estimate penalties for late filing across different tax types
• UK Tax Efficiency Calculator: Compare tax treatment of different income structures

Access Free Tax Calculators

Final Checklist: Never Miss a Deadline Again

Key Takeaways

Meeting tax deadlines isn't just about avoiding penalties - it's about maintaining good financial control, planning cash flow effectively, and ensuring your business remains compliant and reputable.

Remember these critical points:

1. 31 January is the big one: Self Assessment filing and payment, plus first payment on account
2. Monthly PAYE and CIS obligations: These require regular attention on the 19th and 22nd of each month
3. VAT quarters need quarterly focus: Returns due one month and seven days after quarter-end
4. MTD is here and expanding: Ensure you're compliant with Making Tax Digital requirements
5. Companies House has separate deadlines: Don't confuse these with HMRC obligations
6. Early filing reduces stress: File returns as soon as information is available, don't wait for deadlines
7. Penalties escalate quickly: A missed deadline can cost hundreds or thousands in automatic charges
8. Digital tools are essential: Use accounting software and HMRC online services for efficiency

Tax compliance doesn't have to be overwhelming. With proper planning, the right tools, and a systematic approach, you can stay on top of all your obligations and focus on what you do best - running and growing your business.

This guide was created for the 2026 calendar year and covers tax years 2025/26 and 2026/27. Tax law and deadlines can change, so always verify current requirements on the official HMRC website or consult a qualified tax professional for advice specific to your circumstances.