Millions yet to file self assessment returns 06 Jan 2026HMRC has warned 5.65 million self assessment taxpayers to file their tax returns before the deadline on 31 January. 6.36 million people have already filed their tax returns, HMRC revealed. 54,053 taxpayers filed their returns on New Year's Eve or New Year's Day. Taxpayers who miss the self assessment deadline could face an initial late filing penalty of £100. HMRC reiterated that taxpayers can start their tax return, save it and re-visit it as many times as they need to before they submit it. 'The New Year is a great time to start afresh,' said Myrtle Lloyd, Chief Customer Officer at HMRC. 'What better way than to ensure your tax affairs are in order for another year than completing your tax return. If you have yet to start, the clock is ticking, go to GOV.UK and start today.'