HMRC · Self Assessment for trusts

Do you need a trust tax return accountant? The SA900, explained

If a trust is still running — a will trust that continued after the estate was wound up, a lifetime discretionary trust, a life-interest trust for a surviving spouse — and it has income above £500 in a tax year or gains to report, HMRC expects a Self Assessment return in the trust's own name: the SA900. It is due every year the trust stays over the line, it does not stop being due because probate finished, and it is not the same thing as registering the trust in the first place. This page sets out who actually has to file, the £500 rule that lets some trusts out entirely, the deadlines and payments on account, what happens when a return is late, and what "getting an accountant to do it" actually covers.

The SA900 is HMRC's Self Assessment return for a trust, filed by the trustees in the trust's own name. HMRC calls it the Trust and Estate Tax Return, because the same form is also used by the personal representatives of an estate during its administration period — but for a continuing trust it is the trustees' return, covering the trust's own income and chargeable gains for the tax year 6 April to 5 April. It is not the settlor's personal return, and it is not any beneficiary's. A beneficiary who receives trust income reports that on their own return, using the statement the trustees give them (§VI and the R185 question below).

Two routes into filing. The law gives HMRC the power to require a return from any trustee of a trust by notice (TMA 1970 s.8A), and in practice a trust that is registered with HMRC as a taxable trust is issued that notice every year. Separately, trustees who are chargeable to Income Tax or Capital Gains Tax for a year and have not been sent a notice must tell HMRC themselves — the statutory window is six months from the end of the tax year, which is 5 October (TMA 1970 s.7, applied to trustees by s.7(2)). So a trust ends up filing either because HMRC asked, or because it had something to tax and said so.

What “something to tax” means. For income, the line is the £500 rule in §II. For gains, the trust has its own annual exempt amount — £1,500 for the 2026 to 2027 tax year, or £3,000 where a beneficiary is vulnerable — and HMRC's own return guide says the capital gains pages are needed where the trust's taxable gains exceed that amount, where it disposed of chargeable assets worth more than £50,000 even if the gain was small, or where the trustees want to claim a loss or make an election. A sale of UK residential property by trustees has its own separate in-year report, due within 60 days of completion, whatever the SA900 later says.

Who, exactly, is responsible. All of the trustees. HMRC asks that where there are two or more, one is nominated as the principal acting trustee to deal with the trust's tax — but in HMRC's own words the other trustees "are still accountable, and can be charged tax and interest if the trust does not pay." For a will trust, the people named as executors very often become the first trustees when the estate's administration ends, and that is the moment the responsibility changes hands: the estate's SA900 was the personal representatives' return; the trust's SA900 is the trustees' return — a different taxpayer, with its own reference number, even when the same people sign both. If you are still mid-administration rather than running a continuing trust, the estate-side duty is covered on our estate income tax page.

Since 6 April 2024, a trust whose total income for the tax year is £500 or less pays no Income Tax on that income at all. The rule is ITA 2007 s.24B: where the trustees' net income for the year is £500 or less, it is treated as £0. It applies to income of every kind — interest, dividends, rent — and it replaced the old arrangement under which the first £1,000 of a discretionary trust's income was taxed at lower rates. That £1,000 band no longer exists.

Why “cliff edge” is the right description. HMRC's own return guide puts it plainly: the tax-free amount "is not a general allowance, it only applies where the total income is £500 or less. If the income is above this threshold, tax is due on the full amount." So a trust with £499 of income pays nothing; a trust with £501 pays tax on all £501, not on the pound over — and for a discretionary or accumulation trust that means the trust rates, 45% on most income and 39.35% on dividends, from the first pound. It is a threshold, not a slice.

It is an income rule only. The £500 test says nothing about gains. A trust with £300 of interest and a chargeable gain above its £1,500 annual exempt amount still has Capital Gains Tax to work out and report.

One settlor, several trusts. For trusts whose income is taxed at the trust rates — discretionary and accumulation trusts — the £500 is divided by the total number of such trusts the same settlor has made, counting this one, down to a floor of £100. HMRC's guide gives the ladder: one other trust, £250 each; two others, £167; three others, £125; four or more others, £100. Where a trust has more than one settlor, the lowest figure is used. Four kinds of trust are left out of that count altogether and keep the full £500 themselves: trusts whose income is taxed on the settlor because the settlor kept an interest, trusts for a disabled person or a bereaved minor, heritage maintenance funds, and trusts holding assets for a registered pension scheme. An interest-in-possession trust, whose income is not taxed at the trust rates, is neither reduced nor counted.

The knock-on for a life-interest beneficiary. Where an interest-in-possession trust pays no tax because of the £500 rule, the income reaches the beneficiary without a tax credit attached. HMRC's policy paper says that for a taxpaying beneficiary "there will be an additional amount to pay and tax returns may need to be made when that was not previously the case." The trust being under the line does not make the income tax-free in the beneficiary's hands.

What it means for filing. If the trust's total income is £500 or less and it has no gains to report, the trustees have no Income Tax liability for the year, so there is nothing to notify HMRC about under the s.7 duty in §I. But if HMRC has already issued a notice to file, that notice stands until it is withdrawn (§I's callout). HMRC's own consultation summary anticipated exactly this: trustees of a trust that moves either side of the line "may have a continued need to ensure they correctly notify HMRC ... or seek removal from self-assessment for tax years where income is below the de minimis amount." A trust that is under the line one year and over it the next is the case where a notice, or the lack of one, most often gets forgotten.

Checked 3 September 2026 against the statute and HMRC's 2026 return guide: the £500 figure, the £100 floor and the ladder are unchanged since 6 April 2024. Nothing on this page tells you whether your trust is over or under the line — that depends on the trust's own figures.

A trust can be registered with HMRC and still owe nothing on an SA900 that year, and a trust can have a return due while its registration is out of date — because the two are different duties, under different law, with different deadlines. Conflating them is the mistake this section exists to undo.

Put the two side by side and the shapes of the common errors become visible. A discretionary trust holding a house that a beneficiary lives in, with no rent coming in, no sale and no Inheritance Tax event that year, is an express trust holding UK land — so it belongs on the register — yet it has no income, no gains and, if HMRC has issued no notice, no SA900 to file. The year the trustees start letting the house, it becomes liable to Income Tax: it must now be shown to HMRC through the Trust Registration Service as a taxable trust, and the trustees have either a notice to answer or a 5 October notification to make. Two duties switched on by one event, each with its own clock.

The reverse error is quieter. The Trust Registration Service has its own exclusions with their own figures; the fact that a trust owes no Income Tax because of the £500 rule says nothing about whether it has to be registered. And a trust that was registered years ago as non-taxable, then quietly started earning, has a return due and a registration that no longer describes it.

The third thing that gets muddled in: paying the tax. Registering records who the trust is; the SA900 reports what it earned; the tax itself is charged at rates that depend on the trust's type. As GOV.UK states them at 3 September 2026, a discretionary or accumulation trust pays 45% on most income and 39.35% on dividends once it is over the £500 line, and an interest-in-possession trust pays 20% on most income and 10.75% on dividends (8.75% for income arising on or before 5 April 2026). This page is about the filing duty; the rates are noted only so that the three duties are not mistaken for one.

The worked reading above — that a trust can be on the register with no return due that year, and that the moment it becomes liable it owes both — is this page's reading of two separately-stated HMRC duties, not a single sentence HMRC publishes. Each half is HMRC's; the join is ours.

The SA900 runs on the ordinary Self Assessment calendar, with one difference that catches trustees out: HMRC provides no free online filing for it. Filing online means commercial software — bought by the trustees, or used by an accountant filing on the trust's behalf.

Payments on account, plainly. They are advance instalments towards the next year's bill, each normally half of the previous year's liability after tax deducted at source, due 31 January and 31 July. They are required unless either the tax owed last year was less than £1,000, or more than 80% of it was collected at source. Where they apply, the January payment is the balancing payment for last year plus the first instalment for this one — the year the trust first files with tax to pay is the year that combined bill arrives unannounced. Trustees who expect a lower bill can claim to reduce the payments (online, or on form SA303); reduce them too far and HMRC charges interest on the shortfall from the original due date.

No free HMRC filing route — and no Making Tax Digital either. HMRC's SA900 page (last updated 13 May 2026) says it in one sentence: "you'll need to buy software for trust and estate Self Assessment tax returns to do this." Separately, HMRC's Making Tax Digital guidance (updated 28 May 2026) lists "trusts submitting an SA900" as automatically exempt from Making Tax Digital for Income Tax, with trustees told to "continue to submit Self Assessment tax returns as normal." So the April 2026 rollout of quarterly digital reporting did not reach trusts; the annual SA900 remains the return. Both are service facts rather than statute, and either could change without the usual warning — checked 3 September 2026.

The £100 penalty is automatic from the day after the filing deadline, and HMRC's guide is explicit that it is charged "even if there's no tax to pay or any tax owed has been paid on time." Late filing and late payment are penalised separately, and they do not cancel each other: a correct return filed on time does not stop late-payment penalties, and paying in full does not stop late-filing ones.

Nothing in the law requires a trustee to use an accountant to file an SA900. HMRC's own guidance offers both routes in the same breath: "You can also get help, for example from HMRC or by getting an accountant to do your return for you." What the law does require is that the return is complete, correct and on time, and that the trustees stand behind it. The honest question is not whether you are allowed to do it yourself, but what doing it properly involves.

• Identify every source of income and every disposal, by category. The SA900 asks about each separately and sends you to supplementary pages for some of them — SA903 for UK property, SA904 for foreign income, SA905 for capital gains, SA901 for a trade. Missing a page is the same as missing the income.
• Work out which rate the trust pays. Discretionary and accumulation trusts pay at the trust rates once over the £500 line; interest-in-possession trusts pay at the basic and dividend ordinary rates; a mixed trust is taxed part by part. Trust management expenses have their own treatment (HMRC helpsheet HS392).
• Count the settlor's other trusts. Box 9B.1 of the return asks how many other trusts the settlor has made, because the answer sets the trust's own £500 figure (§II). Getting this wrong is a wrong return, not a rounding error.
• Keep the tax pool straight. When a discretionary trust pays income to a beneficiary, HMRC treats it as already taxed at 45%, and the trustees must have paid enough tax over the years to cover that credit — the running total HMRC calls the trust's tax pool. It has to be carried from year to year, and a distribution the pool cannot cover creates an extra charge on the trustees.
• Compute the balancing payment and the payments on account (§IV), or ask HMRC to calculate them by filing on paper by 31 October.
• Give each beneficiary their statement. A beneficiary who was paid income is entitled to ask the trustees for a statement of the income and the tax paid on it — form R185 (Trust Income) — and needs it for their own return. It comes out of the same computation as the SA900, so it is prepared at the same time.

The honest split. For an interest-in-possession trust with one kind of income and one beneficiary, a trustee with the bank statements and the patience can do this. For a trust with several kinds of income, a disposal, discretionary distributions to beneficiaries in different tax positions, a tax pool to carry, or a settlor who made more than one trust, most trustees use an accountant — for the computation, for the software HMRC does not provide, and so that the workings exist in a form HMRC can follow if it asks. That is the point at which the question in this page's title stops being about permission and starts being about judgement.

This page does not give a market fee range for accountants' SA900 work: none was independently verified for it, and a range that is not verified is a number that reads as a fact.

Checked directly against GOV.UK, HMRC's Trust and Estate Tax Return guide (SA950, 2026), and legislation.gov.uk on 3 September 2026. This page is information about how the rules work, not advice on your situation — whether a particular trust is over or under the £500 line, or owes payments on account, depends on its own figures, and a trustee should take advice from an accountant or solicitor before relying on any date stated here.

Three ways to act on this, depending on where you are.

Readers arrive at this page in three different positions: a trustee who has just found out a return is due — or overdue — now; a trustee who is not sure the trust was ever registered in the first place; and someone writing a will or setting up a lifetime trust who wants to know what they are committing a future trustee to. Each has a different next page.