More Than 11.5 Million People Met the 31 January Self Assessment Deadline

This update is for Self Assessment taxpayers who are unsure whether they are among those who missed the 31 January filing deadline, despite reports that more than 11.5 million people filed on time.

Headline figures can be misleading. While many taxpayers meet the deadline each year, anyone who filed after 31 January may already be facing penalties, regardless of how common late filing is, and this is a point often raised by a tax specialist in London.

Late Filing Consequences for Self-Assessment Returns Due on 31 January

Over 11.5 million people met the 31 January 2025 self-assessment deadline, but 1.1 million taxpayers missed it. If you’re one of them, expect a £100 penalty. Learn about late fees and HMRC’s payment plan options and when speaking to a tax advisor in London may help you avoid further charges.

There are an estimated 1.1 million taxpayers that missed the deadline. Are you among those that missed the 31 January 2025 filing deadline for your 2023-24 self-assessment returns?

If you have missed the filing deadline then you will usually be charged a £100 fixed penalty if your return is up to 3 months late, regardless of whether you owed tax or not. If you do not file and pay before 1 May 2025 then you will face further penalties unless you have arranged to pay with HMRC.

If you are unable to pay your tax bill, there is an option to set up an online time to pay payment plan to spread the cost of tax due on 31 January 2025 for up to 12 months. This option is available for debts up to £30,000 and the payment plan needs to be set up no later than 60 days after the due date of a debt.

If you owe self-assessment tax payments of over £30,000 or need longer than 12 months to pay in full, you can still apply to set up a time to pay arrangement with HMRC, but this cannot be done using the online service.

What Happens If You Missed the 31 January Deadline

If your Self Assessment tax return was submitted after 31 January, HMRC will normally issue an automatic £100 late filing penalty. This applies even if no tax is due or the tax itself was paid on time.

If the return remains outstanding, daily penalties of £10 per day can apply once the return is three months late, up to a maximum of £900. Further penalties may follow if the return is still not filed after six months and twelve months.

In Practice – Why Headline Numbers Cause False Reassurance

In practice, we often see taxpayers take comfort from reports showing high on-time filing numbers and assume HMRC will be lenient. Unfortunately, penalties apply individually and automatically once the deadline is missed, regardless of overall compliance levels.

For practical help, experienced accountants in Wimbledon support taxpayers across nearby areas such as Mitcham and Norbury when Self Assessment returns are submitted late and penalties become an issue. At CIGMA Accounting, our team can help you establish whether a deadline was missed and advise on the steps that may reduce or prevent further charges from HMRC.

Review What Happens If You Missed the 31 January Deadline

If you are unsure whether your return was filed on time, clarifying this now can help prevent further penalties or interest. A short review can confirm where you stand and what action is still available.