HM Revenue and Customs is calling on taxpayers to deal with their Self Assessment return well before the cut-off, with 100 days remaining until the 31 January 2027 deadline for the 2025 to 2026 tax year, according to the department.

Key points

  • Scale — around 12 million returns are expected by the deadline.
  • Early filing — taxpayers learn what they owe sooner and get refunds faster.
  • Newcomers — first-time filers must register for a Unique Taxpayer Reference before submitting.
  • Paper returns — the deadline for the 2025 to 2026 year is 31 October 2026.

Returns can be completed on GOV.UK, and a checker tool is available for anyone unsure whether they need to file at all. Myrtle Lloyd, HMRC's Chief Customer Officer, said the deadline was 100 days away and that guidance on GOV.UK could help people get their return done.

There is also help for those filling in sections of the form, including videos and HMRC's digital assistant, while a tax agent, relative, friend or voluntary organisation can assist. Anyone who no longer needs to send a return can tell HMRC through GOV.UK.

Separate arrangements apply in some cases. People with PAYE income can file online by 30 December and have tax owed collected through their tax code. Those on Making Tax Digital for Income Tax must still submit a Self Assessment return and pay by 31 January 2027. Cryptoasset holders owe Capital Gains Tax on gains above the £3,000 allowance and must declare it on their return.

The department also warned about criminals impersonating HMRC to obtain money or personal information, urging people to check that requests are genuine and never to share sign-in details or click links in unexpected messages.

Editor's comment

What it means in practice

If you are one of the millions who file a return, the next few weeks are the least stressful time to do it: you will know your bill early and can plan for it, or get a refund moving sooner. Leaving it to the last days of January narrows your options if something goes wrong.

  • Check your position — use the GOV.UK checker if you are unsure whether Self Assessment applies to you, and register early if you are new, as you need a Unique Taxpayer Reference first.
  • Watch the Winter Fuel Payment — if you receive it and file online, check whether it has been filled in on your return and add it yourself if not; those with total income over £35,000 pay it back through their tax bill.
  • Be wary of messages — HMRC will not ask for sign-in details by text or email, so treat unexpected requests as a possible scam.