Filing a Tax Return for a Deceased Person's Estate

Getting Started

Published on July 8, 2026

When an individual passes away, their personal tax journey stops, but their estate's tax obligations begin. As an appointed executor (named in a will) or an administrator (appointed by court under intestacy rules), you assume full personal responsibility for managing these lingering liabilities.

HMRC treats the period up to the date of death and the subsequent administration period as two entirely separate legal structures, each with distinct rules, allowances, and tax returns.

1. Deceased's Final Return vs. The Estate Return

One of the most common mistakes made during probate is mixing up the deceased person's final individual return with the estate's ongoing tax return. They use different forms, have distinct filing deadlines, and apply different rules:

The Deceased's Final Individual Return

Active Filing Window: 6 April (start of the tax year) up to the exact date of death.
HMRC Form Reference: Standard Form SA100 (Individual Self Assessment).
Income Items to Include: Employment salaries, state/private pensions, dividends, and rental cuts received pre-death.
Statutory Allowances: Receives a Full Personal Allowance (£12,570) and full CGT exemptions (£3,000).
Filing Timeline Ceiling: The later of 31 January following the tax year, or 12 months from the end of the month of death.

The Estate's Administration Return

Active Filing Window: From the day after death until all assets are distributed to beneficiaries.
HMRC Form Reference: Form SA900 (Trust and Estate Tax Return).
Income Items to Include: Bank interest, corporate dividends, and rental profits generated by assets post-death.
Statutory Allowances: No Personal Allowance. Receives a full £3,000 CGT exemption for the year of death and the next two tax years.
Filing Timeline Ceiling: Standard 31 October for paper filings, or 31 January for online filings using specific software.

2. Navigating Post-Death Income Reporting Thresholds

If the estate generates income while you wait for probate or prepare assets for distribution, your reporting method depends entirely on how much income is earned.

The Low-Income Exemption Buffer

For active tax years, estates benefit from a streamlined reporting floor:

If the estate's total combined gross income across all sources (rental profits, dividends, bank interest) stays under £500 inside a single tax year, the income is entirely tax-free. You do not need to report it to HMRC informally or formally.
Note that individual ISAs keep their tax-free status for up to three years after death or until the estate is formally closed. This ISA income does not count toward the £500 reporting threshold.

The All-or-Nothing Rule

If the estate's income hits £501, the £500 buffer is completely wiped out. The estate loses all allowances, and you must pay basic-rate tax on the entire amount earned from the very first pound.

The estate pays fixed basic tax rates: 20% on bank interest and rental profits, and 8.75% on investment dividends. Higher-rate tiers do not apply to estates during the administration phase.

3. Reporting Pathways: Informal vs. Formal (SA900)

If the estate earns over £500, you must choose between an informal check or filing a formal Trust and Estate Tax Return (SA900). Your choice is governed by strict financial boundaries:

The Informal Reporting Pathway

You can bypass the complex SA900 return entirely if the estate clears all three of the following criteria:

The total value of the estate at the date of death is less than £2.5 million.
The total tax due for the entire administration period is less than £10,000.
The total value of assets sold in any single tax year is less than £500,000.

At the end of the administration period, you simply write a formal letter to HMRC detailing your gross income, expenses, and calculated tax liability. You then settle the tax via a single informal payment plan.

The Complex Formal Pathway (Form SA900)

If the estate breaks even one of those criteria, it is legally classified as a Complex Estate and must follow a strict formal process:

{/ Reason: Skipping the Trust Registration Service or using standard individual portals can cause the system to reject the return, triggering severe late-filing fines. /} Log onto GOV.UK and register the estate using the Trust Registration Service (TRS). You must submit this information by 5 October following the end of the tax year in which the income was first generated. HMRC will process your details and issue a unique 10-digit UTR for the estate. If you prefer to file using physical forms, complete the paper Form SA900 alongside any relevant supplementary pages and ensure it reaches HMRC by the 31 October deadline. HMRC’s basic consumer portal does not support SA900 submissions. To file online, you must purchase and use HMRC-approved commercial tax software. The digital return and final tax payment must be finalized by 31 January. When passing the remaining income to beneficiaries, you must provide them with a formal Form R185 (Estate Income) certificate. This form states the exact basic-rate tax the estate has already paid on their behalf, allowing them to claim a tax credit or refund on their personal return if they are basic or non-rate taxpayers.

Key Points to Remember

The pre-death period (SA100) and post-death administration (SA900) are treated as two distinct tax identities.
Estates are exempt from reporting or paying tax if their total annual income across all sources remains under £500.
Crossing the £500 line exposes the entire income to flat basic rates of 20% for interest/rent and 8.75% for dividends.
Estates valued under £2.5m with under £10,000 in tax due can typically settle up using informal letters.
Complex estates must register using the Trust Registration Service and file formal annual SA900 returns.
Online filing for an SA900 return requires the use of specialized, third-party commercial software.

How useful was this article?

☆