HM Revenue and Customs (HMRC) has launched a new registration service for Self Assessment. The updated system went live on 9 September 2026.
Under current rules, anyone who started as a sole trader, became a landlord, or earned other untaxed income during the 2025/26 tax year must notify HMRC by 5 October 2026.
Key deadlines for the 2026/27 cycle
Taxpayers are reminded that while the registration deadline is early October, the deadlines for submitting the actual returns vary depending on the method used:
- 5 October 2026: Deadline to register for Self Assessment for the 2025/26 tax year.
- 31 October 2026: Deadline for submitting paper tax returns.
- 31 January 2027: Deadline for submitting online tax returns and paying any tax owed.
Making Tax Digital and auto-enrolment
This month marks a significant shift in the “Making Tax Digital” (MTD) rollout. From September 2026, HMRC has begun auto-enrolling sole traders and landlords into the MTD system if they have an annual income exceeding £50,000 and have not yet signed up manually. Penalties for late quarterly updates are currently being waived during the 2026/27 transition year.
Winter Fuel Payment repayments
A new policy for the 2026/27 tax year concerns the Winter Fuel Payment. Taxpayers with a total income exceeding £35,000 who received a Winter Fuel Payment may see the amount clawed back as part of their tax calculation through their Self Assessment bill.
