SA900 is HMRC's Trust and Estate Tax Return, the Self Assessment return trustees and personal representatives use to report a trust's or estate's income and gains. For the 2025 to 2026 tax year a paper SA900 must reach HMRC by 31 October 2026, or you can file online with software by 31 January 2027.
Everything below comes from HMRC's SA950 Trust and Estate Tax Return Guide 2026, the SA900 form and GOV.UK's Trusts and taxes guide, as of October 2026.
Deadlines for 2025 to 2026
| What | Deadline | If you miss it |
|---|---|---|
| Paper SA900, or if you want HMRC to calculate the tax | 31 October 2026 | Automatic penalty of £100, even if there's no tax to pay |
| Online return (bought software) | 31 January 2027 | Automatic penalty of £100, plus more if the delay goes beyond 3 months |
| Paying the tax for the year | 31 January 2027 | Interest, and a late payment penalty if unpaid by 1 March 2027 |
This is the detail that saves a penalty. The paper deadline is 31 October 2026, but the guide says that if you miss it you can still file online by 31 January 2027 without a penalty, as long as you didn't send a paper return first. So a trustee who isn't ready by 31 October should switch to online filing rather than post a late paper form.
Who files and what's in it
All trustees and personal representatives receive the first 12 pages of the return. Supplementary pages cover things like trade income and foreign income, and it's your responsibility to include the right ones; the guide's pages 8 and 9 explain which. If there are 2 or more trustees, GOV.UK says to nominate one as the principal acting trustee to manage the trust's tax, although the others stay accountable. A trust also has to be registered with HMRC once it becomes liable for tax.
The tax rates the return works with
| Type of trust | Dividend-type income | Other income |
|---|---|---|
| Accumulation or discretionary | 39.35% (dividend trust rate) | 45% (trust rate) |
| Interest in possession | 8.75% for 2025 to 2026; 10.75% from 6 April 2026 | 20% |
| Estate in administration (personal representatives) | 8.75% dividend rate for 2025 to 2026 | 20% basic rate |
The guide says gains are chargeable to Capital Gains Tax at 24%, with the rate set by the type of asset and the date of disposal. Trustees don't qualify for the dividend allowance. Personal representatives aren't charged at the higher rates, which only apply to individuals.
The 500 pound rule is a cliff, not an allowance
Most trusts pay no Income Tax on income up to a tax-free amount of £500. The guide is blunt: it's not a general allowance. If total income is more than £500, tax is due on the full amount, not just the excess. The same applies to an estate: personal representatives are chargeable on all estate income if it exceeds £500.
For accumulation or discretionary trusts, the £500 is shared across all such trusts made by the same settlor:
| Other trusts made by the settlor | Tax-free amount for this trust |
|---|---|
| None | £500 |
| 1 | £250 |
| 2 | £167 |
| 5 or more trusts in total | £100 each |
Payments on account
Some trustees and personal representatives have to make payments on account. Each is normally half of the previous year's tax liability, after tax deducted at source, due on 31 January in the tax year and 31 July following the tax year. Interest runs on late payments from the date the tax was due.
Bare trusts and settlor-interested trusts
Not every trust's income is the trustees' to report in the usual way. If you're the beneficiary of a bare trust, GOV.UK says you're responsible for the tax on its income and report it on your own Self Assessment return; the £500 tax-free amount doesn't apply, but you may be able to use your Personal Allowance. With a settlor-interested trust, the settlor is responsible for the tax even on income not paid out to them, but the trustees pay it as they receive the income, report it on the SA900 and give the settlor a statement so the settlor can declare it.
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After the return: telling beneficiaries
Trustees must give a beneficiary a statement of the income and the tax paid by the trust if they ask, and form R185 (trust) can be used for this; each beneficiary gets the figures for their share. A beneficiary who doesn't usually file a return may need to register for Self Assessment by 5 October after the tax year and declare the income on SA100.
Filing it
- Check the supplementary pages you need using page 3 of the return and pages 8 and 9 of the SA950 guide.
- Gather the trust's or estate's income records, bank statements and any tax deducted at source.
- Decide paper (by 31 October) or online with commercial software (by 31 January).
- Work out the tax, or leave it to HMRC if you file on paper by 31 October.
- Pay by 31 January and send R185 statements to beneficiaries who ask.
The verdict
If you're a trustee or executor with a 2025 to 2026 return to file and you'll miss the paper deadline, go online instead of posting late: it moves your deadline to 31 January 2027 with no penalty. Watch the £500 cliff closely, because a trust just over it pays tax on every pound, and check the Self Assessment deadlines for the beneficiaries too. For estates, the Inheritance Tax side runs separately on IHT400.
Frequently asked questions
What is the SA900?
It's HMRC's Trust and Estate Tax Return, used by trustees and personal representatives to report a trust's or estate's income and gains under Self Assessment.
When is the SA900 due?
For 2025 to 2026, a paper return must reach HMRC by 31 October 2026, and an online return is due by 31 January 2027.
What is the trust tax rate?
For accumulation or discretionary trusts, 45% on most income and 39.35% on dividend-type income.
Do trusts pay tax on income under 500 pounds?
Most trusts pay no Income Tax if income is within the tax-free amount, normally £500. If income is above it, tax is due on the full amount.
Can I file the SA900 online?
Yes, using commercial software after registering for the online service, which gives you until 31 January 2027 for the 2025 to 2026 return.
