UK Tax Deadlines 2025: Essential Calendar for Accountants and Small Businesses

Staying on top of UK tax deadlines is crucial for avoiding penalties and maintaining good standing with HMRC. Whether you’re an accounting professional managing multiple clients or a small business owner handling your own affairs, this comprehensive calendar will help you stay organized throughout 2025.

Missing tax deadlines can result in significant penalties and interest charges. HMRC’s penalty system means that even a day late can cost hundreds or thousands of pounds, making deadline management essential for financial health.

Key HMRC Tax Deadlines by Month

January 2025

31 January 2025 – Self Assessment Deadline

Final deadline for submitting 2023-24 Self Assessment returns
Final deadline for paying any tax owed for 2023-24
First payment on account for 2024-25 due
Penalty: £100 immediate penalty for late filing, plus additional charges
Source: HMRC Self Assessment deadlines

31 January 2025 – Construction Industry Scheme (CIS)

Monthly CIS return for December 2024
Payment of CIS deductions to HMRC

February 2025

19 February 2025 – PAYE and National Insurance

Monthly PAYE payment for January 2025
Class 1A National Insurance contributions (if applicable)

28 February 2025 – VAT Quarter End

End of VAT quarter for businesses on standard quarterly returns
Returns and payments due by 7 April 2025

March 2025

19 March 2025 – PAYE Payment

Monthly PAYE payment for February 2025

31 March 2025 – Corporation Tax Year End

End of financial year for most companies
Corporation Tax returns due 12 months later (31 March 2026)

April 2025

5 April 2025 – Tax Year End

End of 2024-25 tax year for individuals
Final date for pension contributions to count for 2024-25
Final date for ISA contributions for 2024-25 allowance

7 April 2025 – VAT Return Deadline

VAT return and payment due for quarter ending 28 February 2025

19 April 2025 – PAYE Payment

Monthly PAYE payment for March 2025

May 2025

19 May 2025 – PAYE Payment

Monthly PAYE payment for April 2025

31 May 2025 – Benefit in Kind (P11D)

Deadline for submitting P11D forms for 2024-25
Deadline for paying Class 1A National Insurance on benefits
Source: HMRC P11D guidance

June 2025

19 June 2025 – PAYE Payment

Monthly PAYE payment for May 2025

July 2025

6 July 2025 – P60 Deadline

Final deadline for providing P60s to employees for 2024-25
Source: HMRC P60 requirements

19 July 2025 – PAYE Payment

Monthly PAYE payment for June 2025

31 July 2025 – Self Assessment Payment on Account

Second payment on account for 2024-25 due
Amount: Usually half of previous year’s tax bill

August 2025

19 August 2025 – PAYE Payment

Monthly PAYE payment for July 2025

September 2025

19 September 2025 – PAYE Payment

Monthly PAYE payment for August 2025

30 September 2025 – Corporation Tax Payment

Corporation Tax payment due for large companies (year ending 31 December 2024)

October 2025

5 October 2025 – Self Assessment Notice

HMRC begins issuing Self Assessment notices for 2024-25
Action required: Check your records and begin preparation

19 October 2025 – PAYE Payment

Monthly PAYE payment for September 2025

31 October 2025 – Self Assessment Paper Returns

Deadline for paper Self Assessment returns for 2024-25
Recommendation: File online for later deadline (31 January 2026)

November 2025

19 November 2025 – PAYE Payment

Monthly PAYE payment for October 2025

December 2025

19 December 2025 – PAYE Payment

Monthly PAYE payment for November 2025

30 December 2025 – Self Assessment Online

Recommended deadline for online Self Assessment to allow processing time
Ensures payment can be arranged before 31 January deadline

Small Business Specific Deadlines

VAT Registration Thresholds

Current threshold: £85,000 annual turnover
Registration required: Within 30 days of exceeding threshold
Source: HMRC VAT registration

Making Tax Digital (MTD)

VAT MTD: Mandatory for VAT-registered businesses
Income Tax MTD: Phased introduction from April 2024
Quarterly updates: Required within one month of quarter end
Source: HMRC Making Tax Digital

Corporation Tax Key Dates

Payment deadline: 9 months and 1 day after year-end
Return filing: 12 months after year-end
Quarterly payments: Required for companies with profits over £1.5 million

Penalties for Missing Deadlines

Self Assessment Penalties

Late filing: £100 immediately, then £10 per day after 3 months
Late payment: 5% of tax owed after 30 days, then additional charges
6 months late: Additional 5% or £300 minimum
12 months late: Additional 5% or £300 minimum

VAT Penalties

Late submission: £200 for each late return
Late payment: 2% of VAT owed if 1 month late
Persistent late filing: Surcharge liability notices issued

PAYE Penalties

Late filing: £100 per month for each PAYE scheme
Late payment: Interest charged from due date
Persistent failures: Penalties increase significantly

Source: HMRC penalty and interest rates

Staying Organised: Professional Tips

Use Digital Calendars

Set up automated reminders at least one week before each deadline. Many accounting software packages include deadline management features.

Quarterly Reviews

Schedule quarterly reviews to ensure all obligations are current and no deadlines have been missed.

Client Communication

For accounting professionals: send monthly deadline reminders to clients, particularly before major UK tax deadlines 2025 like 31 January.

Documentation

Maintain detailed records of all submissions and payments. HMRC’s online services provide confirmation receipts that should be saved.

Professional Support

Consider using qualified accountants or tax advisors, especially for complex situations or when managing multiple obligations.

Looking Ahead: 2026 Key Dates

31 January 2026: Self Assessment deadline for 2024-25 tax year
5 April 2026: End of 2025-26 tax year
31 July 2026: Second payment on account for 2025-26

Conclusion

Effective management of UK tax deadlines 2025 is fundamental to successful tax compliance in the UK. By planning ahead and using the UK tax deadlines in this calendar, you can avoid costly penalties and maintain good relationships with HMRC.

Remember that tax legislation can change, and individual circumstances may create additional obligations. Always verify current UK tax deadlines on the official HMRC website or consult with qualified tax professionals when in doubt.

For the most up-to-date information, always refer to HMRC’s official guidance and consider subscribing to their email updates for important changes.

This article provides general guidance based on current HMRC requirements as of September 2025. Individual circumstances may vary, and professional advice should be sought for specific situations. Last updated: September 2025.