UK Tax Deadlines: What You Need to Know for 2025

Keeping track of UK tax deadlines is crucial to avoid penalties, interest charges, and the stress of late submissions. Whether you’re self-employed, run a small business, or simply need to meet your tax obligations, understanding the key dates for 2025 can help you stay organised and compliant.

This guide provides a comprehensive overview of essential tax deadlines for individuals and businesses, covering everything from Self-Assessment tax returns to VAT and Corporation Tax filing. With clear examples and tips, you’ll have everything you need to manage your finances effectively.

Why Staying Ahead of Tax Deadlines Matters

Missing a tax deadline can have serious financial consequences. For instance, failing to file your Self-Assessment tax return by 31 January could lead to an immediate £100 penalty, with additional fines increasing over time. By staying ahead of deadlines, you can avoid such setbacks, ensuring smooth compliance with HMRC requirements.

If managing these dates sounds challenging, don’t worry. Below, we’ll guide you through the most important tax deadlines in 2025 and explain how they may impact you.

Self-Assessment Tax Returns

Individuals who earn untaxed income—such as the self-employed, landlords, or freelancers—must submit a Self-Assessment tax return to HMRC. For most taxpayers, the filing deadline for online submissions is set to 31 January 2026, covering the 2024/25 tax year. To ensure timely payment, it’s essential to pay any tax owed by this same date. Missing the deadline could result not only in fines but also in added interest on unpaid taxes.

Starting early is key. Gather your financial documents well ahead of the deadline to avoid last-minute stress. If you need assistance, HMRC provides detailed guidance on Self-Assessment filing. You can also visit the official government page on Self-Assessment deadlines for more details.

Corporation Tax Deadlines

For UK limited companies, understanding Corporation Tax filing requirements is essential. Companies must submit their Corporation Tax return (CT600) to HMRC within 12 months of their financial year-end. However, any Corporation Tax owed must be paid within nine months and one day after the year-end.

For example, if your company’s financial year ends on 31 March 2025, you would need to settle your tax bill by 1 January 2026 and file your return by 31 March 2026. Staying on top of these deadlines not only avoids penalties but ensures smooth financial reporting throughout the year. Regularly maintaining accurate records can make filing a hassle-free process. The Ross Martin tax deadline calendar is a helpful tool for tracking these key dates.

VAT Returns

VAT-registered businesses must submit returns regularly—typically quarterly—and the deadlines fall one month and seven days after the end of each VAT period. For instance, if your VAT quarter covers 1 April to 30 June, your submission deadline would be 7 August. Filing late or submitting incorrect amounts can result in penalties, so accuracy and timeliness are critical.

To simplify procedures, consider using Making Tax Digital (MTD)-compliant software for VAT. This reduces errors and ensures your returns meet HMRC requirements. For a detailed breakdown of VAT deadlines in the 2024/25 tax year, check the Stellaripe tax calendar.

PAYE and National Insurance

Employers running payroll systems should remember that PAYE and National Insurance Contributions (NIC) payments are due monthly by the 19th if paying by cheque, or the 22nd if paying electronically. Missing a deadline could lead to fines and interest charges, adding unnecessary costs to your business.

If managing payroll feels overwhelming, outsourcing to a professional payroll provider can save time while ensuring compliance with HMRC requirements.

Capital Gains Tax (CGT)

If you’ve sold a second property or an investment asset during the year, you might need to pay Capital Gains Tax. The deadline for reporting and paying CGT is 60 days from the sale's completion date. Preparing early by keeping records of property improvements and any associated costs can help reduce your taxable gains.

Navigating Other Tax Deadlines

From inheritance tax filings to Business Rate instalments, there are numerous additional tax obligations you may need to manage depending on your personal or business circumstances. For every deadline, preparation is essential. Using reminders or working with an accountant can ensure you never miss a due date.

How Virtue Accountants Can Help

Managing multiple tax deadlines can be challenging, but you’re not alone. At Virtue Accountants, we specialise in helping individuals and businesses stay ahead of their tax obligations, offering expert advice on Self-Assessment tax returns, Corporation Tax, VAT, and more. Our tailored services simplify the compliance process, so you can focus on what matters most—growing your business.

Contact us today to ensure your 2025 tax deadlines are under control.