Introduction
Millions of UK taxpayers have been advised by HM Revenue and Customs (HMRC) to file their Self Assessment tax returns by the approaching deadline of 31 January 2026.
The warning comes as the tax authority seeks to ensure that both new and existing Self Assessment customers settle their tax bills on time, avoiding financial penalties for late submission or payment.
Individuals required to submit a return via the online Self Assessment service must ensure all documentation and payments are completed before the cut-off at 11:59pm on 31 January.
Self Assessment deadline looms for taxpayers
The Self Assessment process is a key part of the UK tax system, requiring individuals with certain types of income to report and pay tax annually.
For the 2024/25 tax year, the majority of those required to file a Self Assessment return must do so online before the deadline. HMRC uses public communications channels and official social media posts to remind taxpayers of these obligations.
Who needs to complete a Self Assessment return
Self Assessment is typically required for the self-employed, company directors, certain pensioners, and others with untaxed income.
Those new to the system need a Unique Taxpayer Reference (UTR) to register and file their return. HMRC urges all eligible taxpayers to gather the necessary documents well ahead of the January deadline.
Penalties for missing the tax return deadline
Taxpayers who do not file their Self Assessment return on time face an initial fixed penalty of £100, irrespective of whether they eventually settle any outstanding tax. If the delay extends beyond three months, daily penalties of £10 accrue, up to a maximum of £900.
After six months, HMRC imposes a further penalty amounting to either five per cent of the tax owed or £300, whichever is greater. An additional penalty at the same level is added after twelve months, reinforcing the financial risks of non-compliance.
Steps for those no longer required to file
HMRC has recommended that individuals no longer required to file a tax return proactively contact its offices to formally withdraw from Self Assessment.
According to official guidance, simply failing to submit a tax return does not automatically remove a taxpayer from the system and can generate avoidable fines.
The tax authority’s official social media channel emphasised, 'The Self Assessment deadline is fast approaching. If you no longer need to submit a tax return, let us know as soon as possible.'
Financial penalties for late payment
Besides submission deadlines, separate penalties apply if tax owed is not paid on time. Any outstanding balance not settled within thirty days of the 31 January deadline is subject to a five per cent late payment penalty.
If the debt remains unpaid after six months and again at twelve months, further five per cent charges are applied at each stage.
Final Summary
HMRC’s recent alert serves as a timely reminder for millions of UK taxpayers about their Self Assessment obligations. With the 31 January 2026 deadline nearing, prompt action is crucial to avoid penalties that can quickly escalate.
Taxpayers should check whether they need to file, ensure they have all necessary documents, and pay any tax owed to remain compliant. Those uncertain about their filing status or in need of support should contact HMRC without delay.
For further assistance in managing tax deadlines and compliance, digital solutions such as the Pie app can provide valuable guidance for individuals and businesses.
