HM Revenue & Customs (HMRC) has issued a final-day warning to Britons to register for Self Assessment before Monday night's deadline (October 5) to avoid a £100 fine. Anyone who files their return late will receive an immediate £100 automatic fixed penalty, with further daily penalties of £10 per day for up to 90 days.
HMRC's social media alert
In a post on X, HMRC said: "ALERT: Today is the deadline to register for Self Assessment. Use our online tool to find out if you need to complete a tax return, and register today. Failure to do so could lead to penalties. Act now."
Self Assessment is the system used by HMRC to collect Income Tax from individuals whose tax is not automatically deducted from their income. It typically applies to self-employed individuals, landlords, high earners, and investors.
How to check if you need to file
HMRC says online: "Use this tool to find out if you need to send a tax return for the 2025 to 2026 tax year (6 April 2025 to 5 April 2026). If HMRC wrote to you asking you to send a tax return for the 2025 to 2026 tax year, you must do so by the deadline on the letter. The tool will not send your details to HM Revenue and Customs (HMRC)."
Penalties for late filing
If you file your Self Assessment one day late, you are hit with an automatic £100 fixed penalty. Daily penalties are then handed out of up to £10 per day for up to 90 days. A further penalty of 5% of the tax due or £300, whichever is greater, will apply if the payment is six months late. An additional penalty of 5% of the tax due or £300, whichever is greater, will apply if the payment is 12 months late.
Tax Aid added: "If you get a letter or email that says you need to complete a tax return, but you don’t think you need to, you can ask HMRC to withdraw the return." They continued: "HMRC may withdraw the return if they agree that it was issued in error, and you have no income that needs to be reported on a return. HMRC will not withdraw the return if you had income, but don’t owe any tax. For example, if your business made a loss, you would still have to complete the return, even though you haven’t made any profit to pay tax on."
