A testamentary trust is a trust created by a will rather than during the testator's lifetime. The word "testamentary" simply means "by will". The trust comes into existence on the testator's death; the assets named in the will pass into the trust, where the trustees hold and manage them for the named beneficiaries according to the terms set out in the will. Testamentary trusts are a foundational tool in UK estate planning — used for children under 18, for vulnerable adults, for blended families, and for tax-efficient inheritance planning.
This guide covers what a testamentary trust is, the most common types, how they work in practice, and when they earn their complexity.
Key takeaways:
- A testamentary trust is created by a will and comes into existence on the testator's death.
- Common types include bare trusts (for minors), life interest trusts (for blended families), and discretionary trusts (for flexibility and vulnerable beneficiaries).
- Testamentary trusts let you separate legal ownership (trustees) from beneficial enjoyment (beneficiaries) for added control.
- They are particularly valuable for children under 18, vulnerable beneficiaries, blended families, and inheritance tax planning for larger estates.
- They are not free — trustees need to be paid (or willing to act unpaid), accounts kept, and tax returns filed. Don't use a trust where a clean outright gift would do.
What a testamentary trust actually is
A trust is a legal arrangement separating legal ownership from beneficial enjoyment. Trustees own the trust assets legally — their names appear on bank accounts, property titles, share registers. Beneficiaries are the people the trustees hold the assets for — the ones who actually benefit from the value.
A testamentary trust is simply a trust created by a will. Until the testator dies, the trust doesn't exist; it's just words on paper. On death, the will is admitted to probate, the trust springs into being, the assets named pass into it, and the trustees take over.
This contrasts with an inter vivos trust (Latin for "between the living") — a trust created during the settlor's lifetime by signing a trust deed. Inter vivos trusts are commoner for tax planning during life, asset protection (where appropriate), or holding assets for specific purposes like supporting a disabled adult relative.
The four main testamentary trust types
### 1. Bare trust
The simplest. The trustees hold the asset for a single named beneficiary who is absolutely entitled to it. The beneficiary can demand the asset at age 18 (16 in Scotland).
Used for: Children under 18 receiving any meaningful gift. The trust is a holding mechanism until they're old enough to receive it directly.
Tax: Income and gains are treated as the beneficiary's (not the trust's) for tax purposes. Simple.
### 2. Life interest trust (interest in possession)
One person (the life tenant) has the right to income from the trust or use of the trust asset for their lifetime. After the life tenant dies, the underlying capital passes to the remainder beneficiaries.
Used for: Blended families. The classic case: leaving your share of the home in trust to give your second spouse the right to live there for life, with the property passing to your children from your first marriage after the spouse dies. See our Protective Property Trust guide.
Tax: Treated as if the life tenant owns the trust assets for IHT purposes (under "immediate post-death interest" rules).
### 3. Discretionary trust
The trustees have discretion over which beneficiaries receive what, when and how much. The will names a class of potential beneficiaries (e.g. "my children and grandchildren") and the trustees decide.
Used for: Flexibility — vulnerable beneficiaries (addiction, mental health, learning disability), means-tested benefit situations, family structures where future circumstances are unpredictable.
Tax: More complex. Discretionary trusts face their own IHT regime (10-year periodic charges, exit charges) plus higher rates of income and capital gains tax on undistributed income.
### 4. Accumulation and maintenance / 18-25 trust
A specialised form for children where assets are held until they reach a chosen age (usually between 18 and 25), with the trustees able to use trust funds for the child's maintenance and education in the meantime.
Used for: Avoiding the situation where an 18-year-old receives a large inheritance outright. Holds until 21 or 25, with trustees paying out for university fees, deposit on a flat, etc., in the meantime.
Tax: Modified IHT regime. Less aggressive than discretionary trust rules if the structure is correct.
When a testamentary trust earns its complexity
Three situations where a testamentary trust is clearly the right answer:
1. Children under 18
Any gift to a minor of more than a few hundred pounds is naturally a trust situation. Without a trust clause, the gift either has to be held by the executors (which they may resist) or transferred to a parent (which may not be appropriate). A clean bare trust until age 18 (or higher) is the standard answer.
2. Blended families
Where you want to protect your children's inheritance from a surviving partner who may remarry or who has children of their own. A life interest trust over the family home is the classic structure.
3. Vulnerable beneficiaries
Where a beneficiary cannot manage money safely or where a direct gift would jeopardise means-tested benefits. A discretionary trust lets the trustees protect the beneficiary by controlling distributions.
When a trust is overkill
For a typical estate ("leave it to my spouse, then equally between my children"), trusts add expense and complexity without adding meaningful protection. The spouse exemption from IHT, the residuary clause in the will, and the standard intestacy substitutions for predeceased beneficiaries handle the situation without trust complications.
Resist the sales pitch of "everyone needs an asset protection trust". Most people don't, and badly drafted trusts cause more problems than they solve.
Who can be a trustee
The same considerations as choosing executors but with a longer time horizon:
- Honest — they have a fiduciary duty
- Capable — they have to administer the trust, keep accounts, possibly file tax returns
- Available for the long term — a trust for a 3-year-old beneficiary could run for 18+ years
- Trustworthy with money — they hold legal title to substantial assets
Common choices:
- Adult family members (spouse, adult children, siblings)
- Trusted friends
- A professional (solicitor, accountant, trust corporation) — charges from the trust assets
- A mix of one family member and one professional
Always name substitutes so the trust continues if a trustee dies or refuses to act. You can name up to four trustees in a will.
Trusted Hands handles bare trusts for minor beneficiaries automatically. Our guided builder asks the right questions and inserts standard bare trust clauses where children under 18 are involved. For more complex trust structures (life interest, discretionary, A&M), we recommend regulated solicitor drafting. Start your will →
Letter of wishes alongside a trust
For any testamentary trust with discretionary elements, a letter of wishes is invaluable. It tells your trustees how you'd like them to exercise their discretion — which beneficiaries you'd prioritise in particular circumstances, what kinds of distribution you'd encourage or discourage, the principles you'd want followed.
The letter is non-binding (the trustees retain discretion) but courts have been clear that trustees should give serious weight to a clear letter of wishes when exercising their powers.
Trust administration practicalities
Once a testamentary trust comes into existence, the trustees take on real responsibilities:
- Open trust bank accounts (separate from the trustees' personal accounts)
- Transfer assets into trustee names
- Keep accounts of all trust income, gains and distributions
- Register the trust with HMRC's Trust Registration Service (TRS) if required
- File annual tax returns if the trust has any income or gains
- Make distributions in accordance with the trust terms
- Communicate with beneficiaries about the trust's purpose and operation
This is real work. For a small bare trust holding £10,000 until a child turns 18, the burden is light. For a substantial discretionary trust with property and investments, it's a part-time administrative job.
Frequently asked questions
How long can a testamentary trust last?
In England and Wales, most modern trusts can last up to 125 years under the Perpetuities and Accumulations Act 2009. In practice, most family trusts wind up within 20-30 years.
Can my spouse and I be trustees together?
Yes. Naming both spouses as trustees of a will trust for your children is common. Each spouse is named in the other's will. Just remember that a single trustee shouldn't normally be the sole beneficiary of the same trust fund — it defeats the legal separation.
Do testamentary trusts avoid inheritance tax?
Some structures defer or reduce IHT; others incur their own charges. There is no general rule that trusts = no IHT. Discretionary trusts in particular have their own IHT regime. For significant tax planning, take regulated advice from a specialist.
How much does it cost to set up a testamentary trust?
The trust is created by clauses in your will. The additional drafting cost is usually £200-£800 above a standard will, depending on complexity. The ongoing administration costs depend on the trust's assets and complexity.
Can the beneficiaries collapse the trust?
In some cases yes, under the rule in Saunders v Vautier (1841): if all beneficiaries are adults, of sound mind, and absolutely entitled between them to the entire trust fund, they can agree to terminate the trust and take the assets outright. This applies to bare trusts and some life interest trusts but is rarely available for discretionary trusts.
What happens if a trustee dies?
The surviving trustees continue. If the will named substitutes, they step in. If there are no remaining trustees, the court can appoint replacements — slow and costly. Always name substitutes.
Can I name a charity as a beneficiary of a testamentary trust?
Yes. Charitable trusts have their own legal regime (with significant tax advantages — they're IHT-exempt and income/gains within them are largely tax-free). For a substantial charitable bequest in trust, take advice from a solicitor with charity-law expertise.
Are testamentary trusts the same as living trusts?
No. Testamentary trusts are created by a will and arise on death. Living trusts (inter vivos trusts) are created during the settlor's lifetime by a trust deed. The two have similar mechanics but very different tax and practical implications.
Trusted Hands is a UK will-writing service, not a firm of solicitors. Bare trusts for minor beneficiaries are handled in our guided builder; more complex trust structures benefit from regulated solicitor drafting and we strongly recommend that route for life interest, discretionary, or A&M trusts.
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