Residuary Discretionary Trusts

Something about the Will feels wrong, even on a second read. Instead of "I leave my estate equally to my children", the residue (everything left after debts, expenses and any specific gifts) goes to "my trustees to hold on discretionary trusts" for a list of possible beneficiaries: the spouse, children, grandchildren, perhaps others. Nobody is actually given anything. The family wants to know who inherits, and the honest answer on the face of the Will is: whoever the trustees decide.

That can feel unsettling, even hurtful, at a raw time. But a residuary discretionary trust is almost never a sign of distrust or a drafting error. It is a deliberate structure chosen for flexibility and protection, and it usually comes with a private letter telling the trustees what the deceased hoped would happen. There is also a strict clock running: decisions made within two years of death can be treated, for Inheritance Tax, as if the Will itself had said so. This factsheet explains the structure and the steps to take now.

What a residuary discretionary trust is

A discretionary trust is a trust in which the trustees (the people who legally hold and manage the assets) decide which members of a defined class of beneficiaries (the group of people capable of benefiting) receive money, how much and when. No beneficiary has an automatic entitlement; they have only the right to be considered.

When the trust covers the residue of the estate, the trustees end up holding most or all of what the person owned. Their decisions are made formally, usually by a deed of appointment (a signed legal document recording a decision to give trust assets to a beneficiary).

Nearly every such Will is accompanied by a letter of wishes: a confidential, non-binding note in which the person who died explains who they really wanted to benefit, in what circumstances and why. Finding that letter is one of your first jobs. Conscientious trustees follow it unless there is good reason not to.

Why people set up residuary discretionary trusts

Protection of beneficiaries. Money held at the trustees' discretion is not a beneficiary's property until they receive it. That matters enormously if a beneficiary is going through a divorce, facing bankruptcy, struggling with addiction or not yet ready to handle a large sum. Trustees can wait, drip-feed or support a beneficiary indirectly.

Means-tested benefits. A vulnerable beneficiary who inherits outright can lose means-tested support. A discretionary structure means there is no entitlement to be counted, and the trustees can provide for them carefully. (For some disabled beneficiaries a specific disabled person's trust may be more tax-efficient; advice is needed.)

Second marriages and complicated families. Where fixed shares risk inflaming tensions, or the right division genuinely depends on circumstances at death, discretion lets the trustees respond to the family as it actually is.

Flexibility and post-death tax planning. Because of the two-year rule, a discretionary residue lets the trustees effectively finish writing the Will after death, with full knowledge of the tax rules, the family's needs and the size of the estate.

Older nil rate band planning. Many Wills written before October 2007 contain a discretionary trust of the nil rate band (the £325,000 IHT-free allowance, frozen until April 2031), created when a spouse's unused allowance could not be transferred. Many are now redundant, but they still take effect and need the same two-year review.

The two-year window: section 144 IHTA 1984

Under section 144 of the Inheritance Tax Act 1984, where trustees appoint assets out of a discretionary Will trust within two years of the death, the appointment is "read back" into the Will for IHT purposes: tax is charged as if the Will had left the assets that way, and the appointment itself triggers no exit charge. This is the single most important thing for trustees of a discretionary Will trust to understand.

Within the window, the trustees can:

One timing trap. An appointment in favour of a surviving spouse made within the first three months after death can fail to qualify for read-back (the Frankland trap), forfeiting the spouse exemption. The safe corridor is generally after three months and well before the second anniversary. Take advice before signing anything.

And one tax boundary. Read-back applies for Inheritance Tax only. Capital gains tax is worked out separately, and appointing assets that have risen in value since death can trigger a CGT charge; take advice before choosing which assets to appoint.

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How the trust is taxed if it carries on

A discretionary trust is a relevant property trust (the IHT regime applying to trusts where no one has a fixed entitlement), and it is within that regime from the date of death, not from the second anniversary. What the second anniversary takes away is the read-back opportunity, nothing more and nothing less. If the trustees keep the trust running:

These charges are often a price worth paying for the protection, but they should be a decision, not an accident. Review the trust before each ten-year anniversary.

What executors and trustees need to do now

A worked example

David, a widower, dies leaving a residuary estate of £540,000 on discretionary trusts for his two adult children and his grandchildren, with a letter of wishes asking the trustees to treat the children equally "when sensible". His daughter is financially settled; his son is mid-way through contested divorce proceedings. Six months after death, the trustees appoint half the fund outright to the daughter; under section 144 that is read back into the Will, as if David had left it to her directly. The son's half stays in the trust, out of the matrimonial pot, and the trustees register it on the Trust Registration Service. Three years later, with the divorce settled, they appoint the remaining fund to the son, accepting a modest exit charge as the cost of the protection. This is a hypothetical example for illustration only.

Common mistakes

Letting the two years drift past. Grief, probate delays and indecision eat the window quickly. The trust has been in the relevant property regime since the death; what vanishes at the second anniversary is the read-back opportunity, and it cannot be revived.

Appointing to a spouse in the first three months. The Frankland trap can cost the entire spouse exemption. The dates are technical; ask a STEP-qualified adviser to check the timing.

Treating the letter of wishes as either binding or irrelevant. It is neither. Trustees should give it serious weight while still exercising their own judgment.

Missing the trust register. Trustees who keep the fund going beyond the two-year window often assume probate was the end of the paperwork; HMRC expects the trust to be registered, and the obligation is easy to overlook.

Assuming the discretionary trust itself saves tax. Residue into a discretionary trust gets no spouse exemption and can lose the residence nil rate band. The tax efficiency comes from what the trustees do within two years.

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This factsheet is general information for England and Wales, not legal, tax or financial advice. Last reviewed: June 2026.