What happens if my tax return is submitted late?

The process of tax filing in the UK is fairly straightforward but requires a thorough understanding of the various tax codes, allowances, and deductions. Typically, tax returns have to be filed by the 31st of January following the end of the tax year, which runs from 6th April to 5th April the next year.

Despite this, there are instances when taxpayers might miss this deadline due to various reasons, triggering the filing taxes late penalty. Filing taxes late is not a minor issue. It is not just a simple case of doing your taxes a little late. It can carry significant implications, both financially and legally.

As a taxpayer, it’s crucial to understand the implications of filing taxes late, the penalties involved, and the strategies to avoid them. This knowledge will not only protect you from unnecessary penalties but also empower you to make sound financial decisions.

Understanding the Implications of Filing Taxes Late

Filing taxes late in the UK carries significant consequences that can affect your financial health. The primary implication of filing taxes late is the imposition of a late filing penalty by HMRC. This penalty is not just a flat rate but a cumulative charge that increases the longer you delay your tax filing.

Apart from the financial implications, filing taxes late can also affect your credit score. HMRC shares data with credit reference agencies, and a record of late tax filing could negatively impact your credit score, affecting your ability to secure loans or other forms of credit in the future.

Moreover, if you consistently file your taxes late, HMRC might consider this as a sign of tax evasion, which is a criminal offence. This could lead to a thorough investigation, prosecution, and in severe cases, imprisonment.

The Penalty for Late Payment of Income Tax

In the UK, the penalty for late payment of income tax is designed to encourage taxpayers to file and pay their taxes on time. The penalty starts from a fixed amount of £100 if your tax return is up to three months late. If you’re more than three months late, the penalty starts to increase based on how much tax you owe and how late the tax return is filed.

Additionally, HMRC also charges interest on both the unpaid taxes and the late payment penalties. This interest is calculated from the due date of the tax payment until the payment is made in full.

To help you get an estimate of any penalties applicable, you can use the calculator on the gov.uk website:


It’s important to note that even if you have no tax to pay or you’re due a tax refund, you will still be fined for filing your tax return late. This is because the penalty is for filing the return late, not for paying the tax late.

Strategies to Avoid Filing Taxes Late

There are several strategies that can help you avoid filing taxes late and incurring penalties. One of the most effective strategies is to start preparing your tax return well ahead of the deadline. This gives you ample time to gather all the necessary documents, understand the tax codes, and calculate your tax liability accurately.

Another effective strategy is to keep your financial records organised throughout the year. This not only makes the tax filing process smoother but also ensures that you have all the necessary information at your fingertips when you need it.

In addition, setting reminders for the tax filing deadline can also be helpful. This ensures that you don’t forget about the deadline amid the hustle and bustle of everyday life.

It’s also worth noting that whilst we focus on the deadline of 31st January, that is really the deadline for payment of the tax you owe. You can submit your tax return as soon as the new tax year starts. The benefit of filing your tax return early is that you then know what is due early on, so have longer to prepare/save the tax due. Thus, no last-minute nasty surprises or affordability issues.

If you are late filing the return – what to do

The first step is to pay your tax bill as soon as possible to stop any further penalties and interest from accruing. You can pay your tax bill online, by direct debit, or by bank transfer.

Once your tax bill is paid, if they haven’t already HMRC will send you a penalty notice stating how much you owe. This notice will also explain how to pay the penalty. You should pay this penalty as soon as possible to avoid further charges.

If you cannot afford to pay your tax bill and the penalty, it’s important to contact HMRC as soon as possible. They might be able to arrange a payment plan for you, allowing you to pay your bill and penalty in installments.

Remember, if you feel the penalty is not correct, you can appeal against a late filing penalty if you have a reasonable excuse for filing your tax return late.

Conclusion: The Importance of Timely Tax Filing

In conclusion, timely tax filing is not just a legal obligation but also a crucial aspect of financial health. Filing taxes late can lead to hefty penalties, damage to your credit score, and potential legal issues. Therefore, it’s essential to understand the tax filing process, the implications of filing taxes late, and the strategies to avoid late filing.

As pointed out earlier, don’t forget, that whilst the deadline is 31st January, you can file your tax return without needing to make payment until the deadline.

Please also be aware that in 2026, Making Tax Digital will go live for income tax. This will involve a change in process as you will be required to submit quarterly returns as well as a final submission. If your existing process is very manual and labour intensive, it would be worth discussing how we can help streamline your processes ahead of the changes going live. One advantage of Making Tax Digital is that in theory it should help avoid late filing penalties.

If you would like help with your tax return or have any questions, please get in touch. We’d love to help you.