Secret Trusts in a Will UK: Fully Secret vs Half-Secret Trusts
Updated: 18 May 2026 • Reading time: 8 min
When a will is admitted to probate it becomes a public document — anyone can pay £1.50 and read it. A secret trust allows a testator to provide for a beneficiary without their name appearing in the will or on the probate record. Equity enforces the privately communicated obligation even though it was never made in the formalities of the Wills Act 1837. The price is strict requirements: if the communication or acceptance rules are not met, the secret trustee keeps the property personally — and the intended beneficiary gets nothing.
Two Types of Secret Trust
| Feature | Fully Secret Trust | Half-Secret Trust |
|---|---|---|
| Face of the will | Appears to be an outright gift — no trust mentioned | Expressly states X holds on trust, but does not name beneficiaries |
| Communication timing | Before death; best practice: before or at execution | Must be before or at execution (Re Keen [1937]) |
| If trust fails | Trustee takes absolutely (fraud risk) | Resulting trust back to estate — trustee cannot take personally |
| Key case | Ottaway v Norman [1972] | Blackwell v Blackwell [1929] AC 318 |
The Fraud Principle: Equity vs the Wills Act
The Wills Act 1837 requires a will to be in writing, signed by the testator, and witnessed by two people. Secret trust terms are communicated privately — in a conversation, a letter, a sealed envelope opened after death. They are not in the will and do not meet the statutory formalities.
Equity overrides the statute on the fraud principle: a trustee who receives property on the strength of a private undertaking cannot then invoke the formalities of the Wills Act to keep the property for themselves. In Blackwell v Blackwell[1929] AC 318, Viscount Sumner stated that equity “will not permit a man to keep property which he has obtained by a promise to hold it for another, on the ground that the promise was not in writing.” The doctrine operates dehors (outside) the will — it is a personal obligation imposed on the conscience of the trustee.
Communication and Acceptance
Both types require communication (the testator must tell the trustee of the obligation, the property, and the beneficiary) and acceptance(the trustee must agree — silence when informed is treated as acceptance).
Critical timing difference
For a half-secret trust, communication must occur before or at the time the will is executed. Communication after execution is void (Re Keen [1937]). For a fully secret trust, communication before death suffices — but communicating before execution is the safest approach, as it most clearly satisfies the fraud principle.
What Happens When a Secret Trust Fails
Fully secret trust failure: the trustee takes the property absolutely. The intended beneficiary has no enforceable claim. This is the most dangerous outcome — it rewards the trustee’s failure to honour the private commitment.
Half-secret trust failure: because the will shows on its face that X holds on trust, X cannot take personally. The property is held on resulting trust for the testator’s estate and falls into residue or passes on intestacy. The trustee receives nothing beyond their entitlement under the will as properly construed.
Modern Alternatives to Secret Trusts
- Discretionary trust in the will — the trustees hold for a class of potential beneficiaries and apply income and capital at their discretion; the beneficiaries are named but the trustee’s decision-making is private
- Letter of wishes — guidance to the executor or trustee, not part of the probate record and not legally binding; commonly used with discretionary trusts
- Lifetime settlement — transfer assets to a trust before death so they never form part of the probate estate and are not publicly disclosed
- Nomination — pension death benefits can be directed by a nomination form to any person without appearing in the will or on probate
Frequently Asked Questions
What is a secret trust?
A secret trust arises when a testator makes what appears on the face of the will to be an absolute gift (or a trust without named beneficiaries), having privately communicated to the recipient that the property is to be held for a third party beneficiary who is not named in the will. The trust operates outside the will — 'dehors the will' — and is enforced in equity to prevent the legal recipient using the Wills Act 1837's formalities as an instrument of fraud. Secret trusts allow beneficiaries to remain off the public probate record and were historically used by testators who wanted to provide for a mistress, illegitimate children, or other persons without public disclosure.
What is the difference between a fully secret trust and a half-secret trust?
A fully secret trust: the will contains an apparent absolute gift to X — there is nothing on the face of the will to suggest any trust exists. X has privately agreed (before the will was made, at the time of making, or in some circumstances after) to hold the property for Y. Half-secret trust: the will on its face shows that X holds on trust — 'I give to X to hold upon such trusts as I have communicated to him' — but does not name the beneficiaries. The distinction matters for the timing of communication: communication to the secret trustee must occur before or at the time of execution of the will for a half-secret trust (Blackwell v Blackwell [1929]), but for a fully secret trust, the communication and acceptance may be made at any time before the testator's death (though the dominant view is that communication must be before execution to satisfy the fraud principle — see Ottaway v Norman [1972]).
What is the fraud principle in secret trusts?
The fraud principle is the equitable basis for enforcing secret trusts. Section 9 of the Wills Act 1837 requires a will to be in writing, signed by the testator in the presence of two witnesses who also sign. A secret trust is not made in those formalities — its terms are communicated privately. Equity enforces it anyway because: (1) the secret trustee acquired property by undertaking to hold it for a third party; (2) if equity did not intervene, the secret trustee would be permitted to keep the property for themselves using the statute as a shield; (3) equity will not allow a statute (the Wills Act) to be used as an instrument of fraud. The leading statement is from Viscount Sumner in Blackwell v Blackwell [1929] AC 318: 'A court of equity...will not permit a man to keep property which he has obtained by a promise to hold it for another, on the ground that the promise was not in writing.'
What are the requirements for a valid fully secret trust?
For a fully secret trust to be valid: (1) Communication — the testator must communicate the existence of the trust (including the identity of the beneficiary and the property to be held) to the intended trustee; (2) Acceptance — the intended trustee must accept the obligation, either expressly or by acquiescence (remaining silent when told of the trust is treated as acceptance); (3) Reliance — the testator must have made or left unrevoked the will in reliance on the trustee's acceptance. The communication may be to one of several co-trustees, but see the distinction below about whether communication to one binds all. The trust fails if the trustee predeceases the testator — the property falls into residue (unlike a half-secret trust, where the trustee holds on resulting trust for the residuary estate if the trust fails).
What are the requirements for a valid half-secret trust?
For a half-secret trust: (1) Communication — must take place before or at the time of execution of the will. Communication after execution does not satisfy the requirement for a half-secret trust (Re Keen [1937]); this contrasts with the position for fully secret trusts, where communication after the will but before death may suffice. (2) Acceptance — as for fully secret trusts, acceptance may be express or by acquiescence. (3) The terms communicated must be consistent with the terms of the will — if the will says 'to X on trusts already communicated' but the communication was made after the will, the half-secret trust fails. If the half-secret trust fails, X holds on resulting trust for the testator's residuary estate (or the estate on intestacy).
What happens if a secret trust fails?
Fully secret trust failure: if the trust fails (because communication was insufficient, the trustee predeceased, or acceptance was never given), the secret trustee takes the property absolutely. The intended beneficiary has no claim. Half-secret trust failure: because the face of the will shows that X holds on trust (even if the beneficiary is not named), X cannot take beneficially. The property is held on resulting trust for the testator's estate — it falls into residue or passes on intestacy. The difference reflects the fraud rationale: in a fully secret trust, equity steps in to prevent the trustee's fraud; in a half-secret trust, the trustee was always on notice of the obligation so cannot take personally.
Are secret trusts still used in modern practice?
Rarely. Modern reasons to keep beneficiaries private are better served by: (1) a discretionary trust — a properly drafted discretionary trust in the will names the class of potential beneficiaries but the trustee's exercise of discretion is private; (2) a letter of wishes — non-binding guidance to the executor or trustee, not part of the probate record; (3) a lifetime settlement — transferring assets into a trust before death so they never form part of the estate. Secret trusts remain important academically and arise occasionally in litigation. The risk of failure is high (timing of communication is frequently disputed), and a failed fully secret trust benefits the trustee personally rather than the intended beneficiary. Solicitors generally advise against relying on secret trusts in place of proper drafting.
Keep Your Beneficiaries Private — the Safe Way
Secret trusts carry significant failure risk. WillSafe helps you use modern, reliable alternatives — discretionary trusts, letters of wishes, nomination forms — so that sensitive provisions are private without depending on a doctrine that has defeated many families in court.
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