Running a UK business means juggling multiple compliance obligations across different government agencies. From HMRC tax returns to Companies House filings, keeping track of every deadline can feel overwhelming. Miss just one, and you could face penalties, interest charges, or damaged business relationships.

This comprehensive guide breaks down the ten most critical business deadlines you need to know in 2026, along with practical tips to stay compliant and avoid costly mistakes.

1. Self-Assessment Tax Return Deadline (31 January 2026)

If you are a sole trader or company director taking dividends, your self-assessment tax return for the 2024/2025 tax year is due by 31 January 2026. This deadline also marks when you must pay any tax owed from that year, plus your first payment on account for the 2025/2026 tax year.

Missing this deadline triggers an immediate £100 penalty, with additional charges mounting if you delay further. Start gathering your income records, expense receipts, and relevant documentation well before January to avoid last-minute stress.

2. VAT Return Submission (Quarterly Throughout 2026)

VAT-registered businesses must submit returns quarterly, typically one month and seven days after each quarter ends. Most businesses follow the standard quarters ending in March, June, September, and December, making their 2026 VAT deadlines 7 May, 7 August, 7 November, and 7 February 2027.

Your specific dates depend on your assigned VAT period. Check your VAT certificate or HMRC online account for exact submission dates. Late VAT returns incur penalties and interest, and persistent lateness can result in HMRC surcharges.

3. Corporation Tax Payment (Nine Months and One Day After Year End)

Limited companies must pay corporation tax nine months and one day after their accounting period ends. If your financial year ended on 31 December 2025, your corporation tax payment is due by 1 October 2026.

Unlike other deadlines with built-in grace periods, corporation tax has strict payment timing. Even one day late results in interest charges on the amount owed. Large companies may need to pay in quarterly installments rather than a single annual payment.

4. Annual Accounts Filing (Nine Months for Private Companies)

Private limited companies have nine months from their accounting reference date to file annual accounts with Companies House. For a year ending 31 March 2026, accounts must reach Companies House by 31 December 2026.

Public companies face a tighter six-month deadline. The filing must include a director’s report, profit and loss statement, balance sheet, and notes to the accounts. Late filing penalties start at £150 and escalate based on how overdue your submission becomes.

5. Confirmation Statement (Annually Within 14 Days of Review Date)

Every UK company must file a confirmation statement at least once every 12 months. The deadline is 14 days after your review date, which is typically the anniversary of incorporation or your previous confirmation statement.

This document confirms your company details remain accurate, including registered office address, directors, shareholders, and business activities. Even if nothing has changed, you must still submit this statement. The penalty for missing the deadline is prosecution for the company and its directors.

6. PAYE and National Insurance (Monthly, 22nd of Each Month)

If you employ staff, you must pay HMRC any tax and National Insurance contributions deducted from wages by the 22nd of each month (19th if paying by post). For the 2026 tax year running from April 2026 to March 2027, this means 12 monthly payments.

You also need to submit Real Time Information (RTI) returns to HMRC on or before each payday. Late payments trigger automatic penalties and interest charges, while late RTI submissions can result in fines of up to £400 per month depending on your employee count.

7. Construction Industry Scheme Returns (Monthly, 19th)

Contractors in the construction industry must file CIS returns monthly by the 19th of each month following the tax month end. The tax month runs from the 6th of one month to the 5th of the next.

For example, the return covering 6 January to 5 February 2026 must be submitted by 19 February 2026. These returns detail payments made to subcontractors and deductions taken. Missing the deadline results in automatic £100 penalties, increasing for continued non-compliance.

8. P60 Distribution (31 May 2026)

Employers must provide all employees on the payroll at 5 April 2026 with a P60 form by 31 May 2026. This document summarizes the employee’s total pay and deductions for the tax year.

Employees need P60s for tax returns, loan applications, and claiming tax rebates. Failing to provide them on time can damage employee relationships and result in HMRC penalties for non-compliance with your employer obligations.

9. P11D and P11D(b) Submission (6 July 2026)

If you provide employees with benefits in kind such as company cars, private medical insurance, or interest-free loans, you must report these on P11D forms by 6 July 2026 for the 2025/2026 tax year. You must also submit a P11D(b) form declaring the Class 1A National Insurance due on those benefits.

Benefits reported on P11Ds can significantly impact an employee’s tax liability. Accurate reporting prevents disputes with HMRC and ensures employees understand their true compensation package.

10. Second Payment on Account (31 July 2026)

Self-employed individuals and those with substantial non-PAYE income must make a second payment on account by 31 July 2026 for the 2025/2026 tax year. This payment equals half your previous year’s tax bill.

These advance payments help spread your tax burden throughout the year rather than facing one large bill in January. Calculate carefully to ensure you set aside sufficient funds. If your income drops significantly, you can apply to reduce payments on account to avoid overpaying.

How to Master All Your Business Deadlines

Tracking ten major deadline categories, each with multiple submission dates throughout the year, quickly becomes unmanageable without proper systems. Most businesses use multiple calendars, spreadsheets, and reminder systems, yet deadlines still slip through the cracks.

The key to compliance is automation. When your deadline tracking system connects directly to official data sources and sends real-time alerts to your mobile device, you stop worrying about what you might have missed.

Simplify Compliance with UK Companies House On The Go

While this article focuses on Companies House and related business obligations, managing all these deadlines requires a central hub for tracking your compliance calendar. UK Companies House On The Go helps you monitor critical filing dates, receive advance notifications, and maintain complete records of your submission history.

The app tracks all your Companies House obligations automatically, from annual accounts to confirmation statements. Add multiple companies to your dashboard and receive customized alerts before each deadline arrives. Whether you manage one business or fifty clients, you get instant visibility into every compliance requirement.

Real-time notifications mean you see upcoming deadlines days or weeks in advance, not hours before they are due. This advance warning gives you time to prepare accurate submissions rather than rushing to meet cutoffs. The app works seamlessly on both iOS and Android devices, keeping your compliance information accessible wherever you work.

Professional accountants managing multiple clients benefit especially from centralized tracking. Instead of maintaining separate systems for each client, monitor everyone’s deadlines through a single mobile dashboard. Prioritize urgent filings with the favorites feature and search any UK company instantly when you need additional information.

Take Control of Your 2026 Compliance

Business deadlines do not take holidays, and neither should your compliance system. Download UK Companies House On The Go today and experience how automated tracking transforms deadline management from a source of stress into a routine, manageable process.

App Store: https://apps.apple.com/in/app/uk-companies-house-on-the-go/id6743302358

Google Play: https://play.google.com/store/apps/details?id=com.companiesonthe.go

Start your free seven-day trial and discover why thousands of UK businesses trust UK Companies House On The Go to keep them compliant, on time, and penalty-free throughout 2026 and beyond.