Before you start — which R185 you have, and the one rule that governs the form
SA107 covers three different situations on one two-page form. Work out which R185 you were actually issued before opening it, or you'll fill in boxes that don't apply.
Three sections, three different R185s
Trust income uses figures from an R185 (Trust Income). Settlor-chargeable income uses an R185 (Settlor). Estate income — the section most of Valoren's readers need — uses an R185 (Estate Income), issued by the executor or administrator of a deceased person's estate.
Complete only the section matching the R185 you were given; the notes are explicit about this.
Who files: the recipient, not the personal representative
The executor or administrator's job is to ISSUE the R185 to the beneficiary — they don't file SA107 on the beneficiary's behalf. If the personal representative is also a beneficiary in their own right, they file SA107 for that personal income, in that separate capacity.
Don't send the R185 with the return
The notes say HMRC will ask for the R185 separately if they need to see it — sending it in unprompted with the tax return isn't necessary.
No deadline of its own
SA107 follows whichever SA100 deadline applies: 31 October for a paper return, 31 January for an online one.
SA107 covers three different situations on one two-page form. Work out which R185 you were actually issued before opening it, or you'll fill in boxes that don't apply.