HMRC Warns Of £100 Penalty For Missing January Tax Deadline

Charlotte Baroukh

Tax Expert @ Pie

2 min read

Millions of UK taxpayers are being urged to act quickly as HM Revenue and Customs issues a fresh warning over the fast-approaching Self Assessment deadline.

With just 18 days remaining until the January 31 cut-off, HMRC has confirmed that anyone who fails to submit their tax return and settle any outstanding bill on time risks an automatic £100 penalty.

The alert is aimed primarily at self-employed individuals, landlords, and others required to file a Self Assessment return for the 2024 to 2025 tax year. To help taxpayers meet the deadline, HMRC is strongly encouraging the use of its official mobile app, which has seen a sharp rise in popularity.

As of 2025, more than seven million people were using the app, up from five million the previous year. HMRC says hundreds of thousands have already paid their tax bills through the app since April, highlighting its growing role as a key payment and information tool.

The tax authority has also outlined alternative payment options and support services for those struggling to complete their return or pay what they owe on time.

January 31 Deadline and Penalty Risks

The January 31 deadline is a critical date for anyone required to submit a Self Assessment tax return online. HMRC has confirmed that taxpayers must both file their return for the 2024 to 2025 tax year and pay any tax owed by January 31, 2026.

Missing this deadline triggers an automatic £100 fine, regardless of whether tax is owed or not.

The penalty applies even if the return is only one day late, making early action essential. HMRC regularly reminds taxpayers that additional penalties and interest can build up the longer a return remains outstanding. These can include daily fines after three months and further charges after six and twelve months, significantly increasing the final bill.

HMRC App Usage Surges Ahead of Deadline

HMRC has revealed a substantial increase in the number of people using its mobile app to manage and pay their taxes. Since April 6, 2025, almost 340,000 taxpayers have used the app to make a Self Assessment payment. This represents an increase of 132,788 users compared with the same period last year.

The tax authority says the app offers a quick and straightforward way to pay, view payment history, and keep track of tax obligations.

The growing uptake reflects a broader shift toward digital services, as taxpayers look for faster and more convenient ways to interact with HMRC, particularly during peak periods such as January.

Official Warning from HMRC Leadership

HMRC’s Chief Customer Officer, Myrtle Lloyd, has issued a direct message to taxpayers, urging them not to leave things until the last minute. She said:

"The Self Assessment deadline is less than one month away, and thousands of people have already paid their tax bill via the HMRC app."

"It is quick and easy to do, and you can also see your payment history. Search 'download the HMRC app' on GOV UK to access the app and make your Self Assessment payment."

HMRC believes that using the app can help reduce last-minute pressure and errors, particularly for those who already have a Government Gateway account set up.

Payment Options for Those Who Cannot Pay in Full

HMRC has acknowledged that not everyone will be able to pay their full tax bill by the January deadline.

For taxpayers who owe less than £30,000 and meet certain eligibility criteria, a Time To Pay arrangement may be available.

This allows individuals to spread the cost of their tax bill over manageable monthly instalments.

In addition to the HMRC app, taxpayers can pay directly from a bank account, set up a direct debit, or make an online payment through GOV.UK.

HMRC has confirmed that a full list of accepted payment methods is available on its website, allowing individuals to choose the option that best suits their circumstances.

Support and Guidance Available to Taxpayers

HMRC has emphasised that extensive support is available for anyone struggling to complete their Self Assessment return. Online guidance can be accessed 24 hours a day and includes step-by-step instructions, webinars, YouTube videos, and a digital assistant designed to answer common queries

The tax authority says most issues can be resolved online without the need to speak directly to an adviser. However, for those who do need phone support, HMRC helplines are open Monday to Friday from 8am to 6pm. Phone lines will close on Friday 30 January and reopen on Monday 2 February, after the deadline has passed.

On Saturday 31 January, HMRC will offer webchat support through its Online Services Helpdesk, providing limited assistance on deadline day itself.

What Taxpayers Can Do Using the HMRC App

The HMRC app offers a wide range of features beyond making payments. Users can check their tax code, National Insurance number, income and benefits, and employment history for the past five years. The app also provides access to a user’s Unique Taxpayer Reference, Self Assessment balance, and Child Benefit information.

Additional tools allow users to track forms and letters sent to HMRC, claim refunds, update personal details such as name and address, and choose to receive digital correspondence instead of paper letters. The app also helps users identify gaps in National Insurance contributions and check whether payments can be made to fill them.

The app is available free of charge on both Apple’s App Store and Google Play. Once registered, users can log in securely using a six-digit pin, fingerprint, or facial recognition.

Final Summary

As the January 31 Self Assessment deadline approaches, HMRC is urging millions of taxpayers to take immediate action to avoid an automatic £100 penalty.

With only days remaining, the tax authority is promoting the HMRC app as a fast, secure, and reliable way to submit payments and manage tax affairs. The sharp rise in app usage highlights its growing importance, particularly during the busiest time of the tax year.

For those facing financial difficulty, options such as Time To Pay arrangements offer some flexibility, while a wide range of online guidance and support services remains available. However, HMRC has made it clear that missing the deadline can lead to escalating penalties and unnecessary stress. The message from officials is straightforward: act early, use the tools available, and seek help before the cut-off to stay compliant and avoid extra costs.