Before you start — is SA105 even the right filing
This is the question that matters most for Valoren's audience, and it's easy to get wrong: SA105 covers only ONE slice of a deceased landlord's rental income.
Confirm which slice you're actually dealing with before opening the form.
What SA105 covers: the pre-death stub period only
If the deceased had UK rental income in the tax year they died, up to the date of death, the personal representative completes the deceased's own FINAL SA100 + SA105 — covering 6 April of that tax year to the date of death, and no later.
This is a genuine, common SA105 use case for an executor.
What SA105 does NOT cover: post-death income during administration
Rental income the ESTATE itself receives after death, while it's being administered, is not reported on SA105 at all — this is the mistake to avoid.
For a 'complex' estate — tax liability over £10,000 for the whole administration period, OR estate value over £2.5 million at death, OR asset disposals by the personal representatives exceeding £500,000 in any tax year — the personal representative registers the estate for Self Assessment and files SA900 (Trust and Estate Tax Return) with its own property supplementary page, SA903 (Self Assessment: trust and estate UK property), a separate, differently-numbered form.
For a non-complex, more modest estate, income and gains are typically reported once at the end of administration, through informal correspondence with HMRC, rather than any numbered SA form.
One SA105 per tax year the deceased was letting
If the deceased owned rental property for several tax years before death, only the FINAL year's SA105 is the death-year one — earlier years, if not already filed, follow the same SA105 process but aren't specific to the death itself.
No SA105-specific deadline
SA105 follows whatever deadline applies to the SA100 it attaches to: 31 October for a paper return, 31 January online — there's no separate date for the property page itself. The notes do flag 31 January as the date to tell HMRC if no return turns out to be needed at all.
This is the question that matters most for Valoren's audience, and it's easy to get wrong: SA105 covers only ONE slice of a deceased landlord's rental income.