How do I tell HMRC I'm a landlord?

How do I tell HMRC I'm a landlord? If your rent is over £2,500 after expenses or £10,000 before, and you don't already send a tax return, register for Self Assessment by 5 October after the tax year. For 2026-27 rent, that is 5 October 2027. If you do not usually send a tax return, register for Self Assessment by 5 October following the tax year you had the rent. For the 2026-27 tax year, that is 5 October 2027. Register as soon as you can. GOV.UK says you could get a penalty if you tell HMRC after 5 October 2026. Your online return and any tax for 2025-26 are still due by 31 January 2027. No. The registration deadline is for people who do not usually send a return. Add your rental income on the UK property pages of the return you already send. Read the full answer, with every source, at rightotax.co.uk.