5 October deadline to register for Self Assessment

HMRC has set 5 October 2026 as the deadline to tell it if you need to complete a Self Assessment tax return for the 2025–2026 tax year. This applies if you're new to Self Assessment, for example because you started letting a property or your rental income has grown enough to bring you into scope.

If you already completed a Self Assessment return last year, you do not need to register again. If you're unsure whether your income means you need to register this year, HMRC has an online tool to check.

Separately, HMRC has confirmed how Furnished Holiday Lettings (FHL) are taxed from the 2025–26 tax year. The FHL rules end from 6 April 2025 for Income Tax and Capital Gains Tax (1 April 2025 for Corporation Tax). From this point, FHL income is combined with other UK or overseas property income and taxed under the normal property income rules, rather than being treated separately.

The deadline to submit the 2025–26 Self Assessment return itself is 31 January 2027.

This is HMRC guidance on Self Assessment registration, which applies across the UK: England, Wales, Scotland and Northern Ireland. It affects any landlord in any of these nations who has rental income and has not previously registered for Self Assessment.

Landlords who previously ran a Furnished Holiday Let and reported it separately need to check how their income is now taxed under the combined property income rules from the 2025–26 tax year.

Check whether you already registered for Self Assessment in a previous year. If so, you don't need to register again.,If you're newly letting a property, or your income has crossed the reporting threshold, register with HMRC by 5 October 2026.,Use HMRC's online tool to check if you need to complete a tax return if you're unsure.,If you have or had a Furnished Holiday Let, check with your accountant how the 2025–26 change to combined property income rules affects your return.,Note the return submission deadline is 31 January 2027, separate from the 5 October registration deadline.