Introduction
Trusts play a vital role in English law as creatures of equity, allowing one person (the trustee) to hold and manage assets for the benefit of others (the beneficiaries). This split between legal ownership and equitable interest is a hallmark of trust law. A trust is essentially an obligation enforceable in equity: for example, a UK Government definition provides that “A trust is an obligation binding a person (a ‘trustee’) to deal with property in a particular way for the benefit of another person or class of persons… whose interests… are protected by the equitable jurisdiction of the courts” (gov.uk). In order for an express trust (one intentionally created by a settlor) to be valid and enforceable, it must satisfy the three certainties doctrine established in English law. These three certainties – certainty of intention, certainty of subject matter, and certainty of objects – were famously outlined by Lord Langdale MR in Knight v Knight (1840). In that case, the court held that the settlor must indicate with sufficient clarity an intention to create a trust, the specific property to be subject to the trust, and the beneficiaries (or permissible objects) of the trust. The rationale is that unless a trust’s essential terms are certain, the court cannot enforce trustees’ duties or ensure the trust’s administration aligns with the settlor’s wishes.
This essay will explain each of the three certainties in turn, with reference to leading cases and authorities in English trust law. Short, clear examples will illustrate how courts determine whether each certainty is met. After examining the traditional doctrine, the essay will discuss recent developments and debates – including modern judicial and academic perspectives – about the three certainties and potential reforms.
Certainty of Intention
Certainty of intention means it must be clear that the settlor (the person who creates the trust) truly intended to impose a binding trust obligation on the trustee, as opposed to making a gift or merely expressing a hope or wish. The court looks at the words used and the context or conduct of the settlor to decide if a trust was intended. No particular form of words is necessary – the settlor need not explicitly use the word “trust” – so long as in substance a sufficient intention to create a trust is manifested. As Megarry J observed in Re Kayford [1975], “it is well settled that a trust can be created without using the words ‘trust’ or ‘confidence’ or the like: the question is whether in substance a sufficient intention to create a trust has been manifested.”. The courts will therefore construe the whole of the settlor’s words and actions in context to decide if they meant to create a trust.
If the language used is imperative (commanding or directing that the property be held or applied for someone), it points to a trust; if it is precatory (expressing a wish, hope, or moral obligation), it generally will not create a trust. This principle was established in the late 19th century in cases like Lambe v Eames (1871), where a testator gave property to his widow “to be at her disposal in any way she may think best, for the benefit of herself and her family.” The court held this did not create a trust – the words were precatory and imposed no binding obligation on the widow. As Sir Malins VC stated, to establish a trust you “must show a clear intention” to do so. The result was that the widow took the property absolutely (outright) since no trust was found. Similarly, in Re Adams and the Kensington Vestry (1884), a husband left all property to his wife “in full confidence that she would do what was right by his children.” The court held this was only a hope, not a trust – the wife was not legally bound to hold it for the children, so she took the assets for herself free of trust. These cases illustrate that mere expressions of wish or confidence are insufficient; the settlor must intend to impose a duty on the trustee.
On the other hand, where the language or conduct indicates a clear intention to create a trust, the courts will give effect to it even if informal. In Comiskey v Bowring-Hanbury [1905] AC 84, a testator’s will left his estate to his wife “absolutely in full confidence that she will make such use of it as I should have made myself… and that at her death she will devise it to such one or more of my nieces as she may think fit, and in default of any disposition by her… I hereby direct that all my estate… shall at her death be equally divided among the surviving said nieces.”. Although part of this wording (“in full confidence”) was precatory when read alone, the House of Lords (then the highest court) held that taken as a whole the will demonstrated an intention to create a trust in favor of the nieces. The critical factor was the later mandatory language (“I hereby direct…shall be…divided among the nieces”), which showed the testator meant to impose a binding trust and not leave the matter solely to the wife’s goodwill. Thus, the wife was deemed a trustee (with a life interest), and the nieces were beneficiaries of the remainder, rather than the wife receiving an absolute gift. This contrast between Re Adams (no trust) and Comiskey (trust) – despite both containing “in full confidence” – underlines that the entirety of the document and circumstances determine intention; a seemingly precatory phrase can be overcome by other directive language in the instrument.
Trust intention can also be inferred from conduct and spoken words in non-formal situations. A well-known example is Paul v Constance [1977] 1 WLR 527. There, a man (Mr. Constance) had separated from his wife and was living with a new partner (Mrs. Paul). He opened a bank account solely in his own name but repeatedly told Mrs. Paul that “the money [in this account] is as much yours as mine,” and they treated the account funds as joint monies (e.g. joint bingo winnings were deposited, and both withdrew for shared purposes). When Mr. Constance died intestate, the question was whether he had declared a trust of the account for himself and Mrs. Paul (which would give her a beneficial entitlement) or whether the money was entirely his estate’s. The court held that a trust had been declared: Mr. Constance’s words “this money is as much yours as mine,” along with the way the account was used, demonstrated a clear intention to hold the money in trust for the both of them in equal shares. Paul v Constance shows that even in casual contexts, the courts will find the requisite intention for a trust if the substance of what was said and done conveys an intention to share ownership in the manner of a trust. No technical wording was needed; equity looks to intent rather than form.
Conversely, if it appears that there was no genuine intention to create a trust – for example, the arrangement is a sham or a mere facade – then there is no certainty of intention and the trust will be void. In Midland Bank v Wyatt [1995] 1 FLR 696, a husband executed a trust declaring his home was held on trust for his wife and daughter, at a time when he was facing financial difficulty. He retained the deed at home, never informed his wife or acted as though the property was truly held for them, and continued to treat the house as his own. The court found that this “trust” was a sham, intended to put the home beyond reach of creditors while not sincerely divesting the husband of beneficial ownership. Because the settlor had no true intention to impose enforceable duties on himself as trustee for his family, the certainty of intention requirement was not met – the document did not reflect a bona fide trust intention. The result was that the trust was void and ineffective. This illustrates that courts will probe the reality of intention; a trust must be intended in substance, not just in appearance or form.
In summary, certainty of intention is about ensuring the settlor meant to create a trust. The courts examine all the relevant words and actions of the settlor. Precatory expressions (hopes, wishes) are insufficient to establish a trust obligation, whereas imperative words or clear conduct can demonstrate the necessary intention. If certainty of intention is absent, the would-be trustees hold no trust – depending on the situation, the property might remain with the recipient as an absolute gift (as in Lambe v Eames) or result back to the settlor’s estate. Certainty of intention thus underpins the creation of a trust: without a definite intent to create a trust, there is simply no trust for equity to enforce.
Certainty of Subject Matter
The second certainty required is certainty of subject matter – the trust property itself must be specified with sufficient clarity. This actually encompasses two aspects: (a) the property intended to be held on trust must be clearly identifiable, and (b) the beneficial share or entitlement of each beneficiary (in a fixed trust) must be certain. In simple terms, one must be able to point to what property is held in the trust and how it is held for the beneficiaries.
For a trust to exist, there must be some identifiable property – often called the trust fund or trust res. If the wording of the trust is so vague or ambiguous that it is impossible to determine what property (or how much of some larger property) is subject to the trust, the trust will fail for uncertainty of subject matter. A classic illustration is Palmer v Simmonds (1854), where a testatrix attempted to create a trust of “the bulk of my residuary estate” in favor of certain beneficiaries. The court held that this description – “the bulk” – was too uncertain to delineate what portion of the estate was meant to be held on trust. Vice-Chancellor Kindersley noted that while a phrase like “the residue of my estate” could be given a definite meaning (it implies the remainder after debts and legacies, which is calculable), the phrase “the bulk of my residuary estate” had no clear quantifiable meaning and thus was not sufficiently certain. Because the trust property could not be ascertained, the trust failed – the intended beneficiaries could not enforce anything since it was unclear what they were entitled to. Similarly, in Sprange v Barnard (1789), a testatrix left certain money to her husband, stating that whatever was left of that money when he died should go to specified relatives. It was uncertain at the testatrix’s death what (if anything) would be “left” for the relatives, because the husband might spend or use the funds. The court found the subject matter of the trust (the remaining part of the money) was not certain at the time of the gift, so no trust in favor of the relatives was created – the husband took the sum outright.
The courts require that the specific property to which the trust attaches be identified, especially when the trust is only over part of a larger asset or collection. If a settlor says “I hold some of my property on trust” without specifying which property or what portion, it will likely be too uncertain. This issue often arises when part of a homogeneous bulk of assets is allegedly held on trust. For example, in Re London Wine Co (Shippers) [1986] PCC 121, customers paid for bottles of wine from a merchant and the wine was stored in the seller’s warehouse, but specific bottles were never segregated or earmarked for each customer. When the company went insolvent, the question was whether those customers had a trust over certain bottles of wine. The court held any purported trust failed for uncertainty of subject matter – since the particular bottles for each customer had not been separated from the general stock, no one could say which bottles (which property) were held for which customer. The customers were therefore merely unsecured creditors, not beneficiaries of a trust, because the subject matter of the trust was not certain (the wine was an unallocated part of a larger bulk). By contrast, English law has taken a more liberal approach with intangible fungible assets. In Hunter v Moss [1994] 1 WLR 452 (CA), a man declared a trust over 50 of his 950 shares in a company, but he did not segregate or distinguish which 50 shares were to be the trust property. The Court of Appeal upheld the trust, reasoning that shares (being intangible and all identical in rights) did not require segregation – a trust of an undefined portion of a homogeneous mass of intangible assets could be certain. Essentially, the court drew a distinction: if the assets are indistinguishable units (like shares of the same class), declaring a trust of a specified number or percentage is sufficiently certain even without earmarking specific ones, whereas with tangible items (like particular bottles of wine or gold bars) traditional thinking required segregation. The Hunter v Moss decision has been debated. It was followed (with some reluctance) by the High Court in Re Harvard Securities (1997) where Neuberger J felt bound to apply Hunter for shares. Some commentators praise the practicality of Hunter in preventing an intended trust from failing merely for want of formality, while others criticise the intangible/tangible distinction as logically “spurious”, arguing that fundamental property law requires identifiable property in any trust, and that identical tangible items pose the same issue as shares. Nonetheless, as of today, Hunter v Moss remains good law in England, meaning a trust of part of a bulk of intangible identical assets can be upheld without pinpointing the exact units, whereas with tangible assets specificity is needed.
Apart from identifying the trust property itself, certainty of subject matter also requires certainty of the beneficial entitlements – particularly in a fixed trust where the shares are defined by the settlor. The seminal illustration here is Boyce v Boyce (1849). A testator left several houses on trust for his daughters, stipulating that his elder daughter, Maria, should choose one house for herself, and the remaining house(s) would then be held for the younger daughter, Charlotte. Maria died before the testator and thus never made any choice of house. This left it impossible to ascertain which house was intended for Maria (since no choice was made) and which for Charlotte – the trust failed because the beneficial allocation was uncertain. In other words, although the bulk property (the set of houses) was known, the uncertainty was in “who gets what”. The court could not enforce the trust for Charlotte because it could not be determined which specific house she was meant to receive. Consequently, the property resulted back to the testator’s estate. Boyce v Boyce exemplifies that if the method of distributing the trust property between beneficiaries is too uncertain (here contingent on an event that did not occur), the trust may fail. The Boyce scenario is one reason some academics argue “distributional certainty” should be recognised separately – the idea that where a trust involves dividing property among several beneficiaries, the shares for each must be sufficiently clear. In traditional analysis, this issue has been treated as part of subject matter certainty (since it deals with the extent of each beneficiary’s interest). The key point for the three certainties is that both the property and the quantum of interest must be certain.
The courts will, however, strive to give effect to a trust where the general intention is clear, sometimes by implying a solution if possible. An example is Burrough v Philcox (1840), where a testator gave property in trust for his children for life, and provided that if his children had no offspring, the survivor of the children could choose how to distribute the remainder among the testator’s nieces and nephews. In the event, the surviving child did not exercise that power to choose. The court held that the testator had a general intention to benefit the nieces and nephews, so rather than letting the trust fail, it applied the principle “equality is equity” and divided the property equally among all the nieces and nephews. In modern terms, the court found a trust with implied equal shares, effectively resolving the uncertainty by construing the settlor’s overarching intent. Likewise, in Re Golay’s Will Trusts [1965] 1 WLR 969, a testator directed his executors to let a beneficiary, Miss Golay, “enjoy one of my flats during her lifetime and to receive a reasonable income from my other properties”. The phrase “a reasonable income” was challenged as uncertain (how much is “reasonable”?). Ungoed-Thomas J held that this was objectively ascertainable and therefore sufficiently certain – the court could determine what a “reasonable” income was in the circumstances, by objective standard. Because the yardstick of reasonableness could be applied, the trust did not fail: the court noted that terms like “reasonable” have been upheld in other contexts (such as a “reasonable provision” for someone can be assessed by the court). Re Golay demonstrates that not every ambiguity is fatal; if the court can find a workable standard or infer an intention (like equal division or reasonableness), it may save the trust. However, the courts will not rewrite a settlor’s intention entirely – they will only infer or apply default principles where it is appropriate and consistent with the settlor’s likely intent.
In summary, certainty of subject matter requires that we know what property is held on trust and any division of that property between beneficiaries is clear. If the subject matter is uncertain – for example, an uncertain portion of a larger fund, or an unclear measure of how much each beneficiary receives – then the trust (or at least that part of it) is void for uncertainty. The property in such a case typically remains with the would-be trustee or falls back to the settlor or estate via a resulting trust. The law’s insistence on this certainty is to ensure a trustee (and court) can definitively identify the trust property and allocate it as the settlor intended. Recent cases and commentary have tested the boundaries of this requirement (such as allowing trusts of unsegregated fungible assets in Hunter v Moss), but the core principle endures that a trust without identifiable trust property or clear beneficial shares is no trust at all.
Certainty of Objects
The third certainty is certainty of objects, referring to the need for the beneficiaries or objects of the trust to be sufficiently certain. In a private trust, the “objects” are the persons who are intended to benefit from the trust – essentially, the beneficiaries. The rule is often stated that a trust must have definite objects so that the trust obligations can be enforced. As Sir William Grant MR famously put it, “there must be somebody in whose favour the court can decree performance” (Morice v Bishop of Durham (1805) 9 Ves 399) – a private trust typically cannot exist for an uncertain or abstract purpose with no beneficiaries, because no one could hold the trustees to account. Thus, certainty of objects is about being able to identify who the beneficiaries (or permitted purpose, in certain cases) are, with enough clarity that the trustees (or the court) can determine who is entitled to benefit.
The degree of certainty required for objects can vary depending on the type of trust. For a fixed trust, where the settlor has defined exact shares or benefits for each beneficiary (or a class of beneficiaries), the traditional test is often called the “complete list” test – it must be possible to draw up a complete list of all beneficiaries. In IRC v Broadway Cottages Trust [1955] Ch 20, the Court of Appeal held that a trust (in that case, a fixed trust for a class) was invalid unless it was possible to ascertain every member of the class of beneficiariesclassic.austlii.edu.au. In other words, if the trust says income to be divided equally among “my employees’ children,” one would need to identify all those children to distribute the income; if it’s fundamentally impossible to say who all are included, the trust fails. This strict approach ensured that the trustees could discharge their duty to distribute the trust property to all entitled beneficiaries.
However, for discretionary trusts – where the trustees have discretion to choose who, among a class of potential beneficiaries, will receive benefits and in what amounts – the certainty of objects test was relaxed by the House of Lords in the landmark case McPhail v Doulton [1971] AC 424 (also known as Re Baden’s Deed Trusts No. 1). The settlor in McPhail had created a trust for the benefit of the staff of a company and their relatives and dependants, with trustees empowered to choose among them (so a classic discretionary trust). The House of Lords, departing from the older complete-list rule for such trusts, adopted the test used for mere powers of appointment from Re Gulbenkian’s Settlements [1970] AC 508. Lord Wilberforce held that the trust is valid if it can be said with certainty whether any given individual is or is not a member of the class of beneficiaries. This is often called the “any given postulant” test or the test of conceptual certainty of the class. In practice, it means the description of the class of beneficiaries must be clear enough that, for any person, one can determine definitively whether they qualify or not. It is not necessary to compile an exhaustive list of everyone in the class, which might be very burdensome for large classes; it suffices that you can test any particular case. Thus, after McPhail v Doulton, a discretionary trust would be valid as long as the class of objects is defined in conceptually certain terms. The trustees must still distribute or at least consider distributing the property among that class, but they don’t need to identify every member beforehand – they can proceed by identifying eligible recipients when making distributions.
An important aspect of certainty of objects is conceptual vs. evidential certainty. Conceptual certainty (sometimes called “linguistic” or “semantic” certainty) means the language defining the class of beneficiaries has a clear meaning. For example, “children” or “spouses” or “first cousins” are conceptually certain terms in law; “friends” or “good people” would likely be conceptually uncertain because reasonable people can interpret those in many different ways. Evidential certainty refers to the practical ability to find or prove the identity of the persons within that class. A class might be conceptually clear (“children of X”), but evidentially difficult if X’s family records are lost, etc.; however, mere difficulty in evidence does not render a trust invalid – the trust won’t fail just because it is hard to find all the beneficiaries, as long as the class itself is defined clearly. In the context of discretionary trusts, the House of Lords in McPhail indicated that conceptual certainty is required, whereas evidential certainty (being able to identify every person or having complete information) is not strictly required in the same way. This was further explored in the Court of Appeal in Re Baden’s Deed Trusts (No. 2) [1973] Ch 9, on remission from McPhail. In Re Baden (No. 2), the judges agreed that “relatives” (the term used in the trust deed) was conceptually certain – they variously defined it as either “next of kin” (Stamp LJ’s approach) or “descendants of a common ancestor” (the broader approach of Sachs and Megaw LJJ). All three appellate judges found the trust workable, though they had slightly different takes on how to handle individuals whose status was uncertain. Notably, Sachs LJ held that once a class is conceptually certain, the burden is on claimants to prove they fall within it; if they cannot, that doesn’t invalidate the trust, it just means those individuals cannot benefit. This pragmatic approach ensured that evidential gaps (not being sure if a particular person is a “relative”) would not make the entire trust void – it would only mean that person might not be included absent proof. The upshot is that as long as the class description is clear in principle, the trust can be upheld, and the courts or trustees will do their best with evidence to identify members. By contrast, if a class is conceptually uncertain – e.g. a trust “for my friends” – it fails from the outset because nobody can say with any precision what qualifies someone as a “friend” in this legal context (Brown v Gould (1972) is an example where “old friends” was deemed too subjective and unclear). The McPhail test therefore demands a clear concept for the group of beneficiaries.
Another limitation related to certainty of objects is administrative unworkability. This is a kind of outer limit: even if a class is conceptually clear, if it is so broad that it cannot reasonably be administered as a trust, the trust may be invalid. In McPhail v Doulton, Lord Wilberforce gave the example that a trust for “all the residents of Greater London” might be held void – not because “residents of Greater London” is unclear in meaning (it’s conceptually quite clear), but because the class could encompass millions of people and trying to perform a trust duty (to survey the range of possible beneficiaries and make discretionary distributions) would be hopelessly unworkable. A real case illustrating this is R v District Auditor ex parte West Yorkshire MCC (1986) 26 RVR 24. There, a local council tried to create a trust for “the inhabitants of the County of West Yorkshire” (some 2.5 million potential beneficiaries) with a fund of £400,000. The court struck it down as administratively unworkable – a class so large defeated the ability of trustees to make any sensible selection or distribution. It was not a question of conceptual uncertainty (who an “inhabitant” is was clear enough) but rather that the trust obligation could not realistically be fulfilled for so unwieldy a class. Another related concept is sometimes called capriciousness: if a settlor’s description of beneficiaries is one that has no rational link to any charitable or sensible intent – for instance, a trust for “the first 10 people I see on the street each day” – a court might void it for capriciousness. This is relatively rare; the more common issue is just that extremely large classes can render a trust non-viable even if technically certain.
If a private trust fails for uncertainty of objects, the normal result is that there is a resulting trust of the property back to the settlor or the settlor’s estate. The trustees cannot take beneficially (because the settlor’s intention was not to benefit them), but since the intended trust cannot operate, equity returns the property to the next logical claimant – usually the settlor, or in a will, the residuary estate. This happened in the early case of Morice v Bishop of Durham (1805) mentioned above: a trust “for such objects of benevolence and liberality as the Bishop of Durham shall approve” was too uncertain (and not a valid charitable trust), so it failed and the funds reverted to the estate of the testatrix rather than being applied at the Bishop’s discretion. The requirement of certainty of objects is thus tied to the beneficiary principle: except in the case of valid charitable trusts or a few anomalous purpose trusts, every trust needs ascertainable beneficiaries who can enforce it. Charitable trusts are an important exception – they do not require specific human beneficiaries, as the Attorney General can enforce charitable purposes, and the purposes themselves must be within the legal definition of charity. In the context of the three certainties, charitable trusts are often said to be exempt from the certainty of objects requirement because their “objects” are purposes beneficial to the public rather than named persons. For example, a trust “for the relief of poverty in X town” is charitable and valid even though no particular individuals are named – it’s enough that the purpose is certain and charitable. Private purpose trusts (trusts not for people or charities but for purposes) generally fail for lack of beneficiaries (exceptions include trusts for the care of specific animals or graves, which are allowed as special cases). The three certainties primarily apply to express private trusts for beneficiaries.
In summary, certainty of objects requires that the beneficiaries of the trust (or the class from which they are to be chosen) are described with sufficient clarity that it is objectively ascertainable who is within the class and who is not. For fixed trusts, this means the ability to identify all beneficiaries (or at least all categories of beneficiaries). For discretionary trusts, since McPhail v Doulton, it means the class must be defined such that any given individual could be tested against the description and it be determined whether they qualify. Vague or subjective terms will cause the trust to fail, whereas reasonably precise terms (even if broad) will satisfy this certainty as long as they are conceptually clear. The law has evolved to be more flexible for discretionary trusts, reflecting their usefulness in modern estate and business planning, but it still guards against trusts that are too uncertain or cumbersome to enforce. Certainty of objects ensures there is someone with standing to enforce the trust and that the trustees can carry out their duties knowing the scope of their beneficiary class.
Recent developments and reforms
The doctrine of the three certainties in trust law is longstanding, originating from the 19th-century case law, and it has proven to be a robust foundation for determining trust validity. In modern times, the core principles of intention, subject matter, and objects remain fundamentally unchanged, but there have been developments in interpretation and ongoing academic and legal discussions about refining or reforming these rules. After covering the traditional doctrine, it is useful to consider some recent developments and debates that shed light on how the three certainties operate in the 21st century.
One notable development (though now itself half a century old) was the relaxation of the certainty of objects test for discretionary trusts by the House of Lords in McPhail v Doulton (1971), discussed above. This change – allowing trusts with large classes of beneficiaries to be upheld on the “is or is not” test – has had a lasting impact on the use of trusts. It essentially revolutionised the modern discretionary trust. By removing the need for a complete list of beneficiaries, English law enabled settlors to create trusts benefiting wide classes (such as all family members or employees) without fear of automatic invalidity. This innovation in the late 1960s and early 1970s has been described as a “significant reform” of object certainty requirements, and it paved the way for the widespread use of discretionary trusts in family wealth management, pension schemes, and employee benefit trusts. According to scholarly analysis, this reform not only affected the doctrinal test but also had important implications for the theoretical conception of the trust and the modern practice of discretionary trusts. In practice, discretionary trusts have become extremely common, precisely because the law now accommodates them so long as the class of beneficiaries is conceptually certain and not administratively unworkable. The legacy of this development is evident in how trust deeds are drafted today – settlors often define broad classes (e.g. “all my descendants and their spouses”) knowing that the trust will be upheld if drafted with conceptually clear terms, whereas prior to 1971 such a broad class might have been problematic.
Another area of modern case law elaboration concerns certainty of subject matter, especially with assets like funds and securities. A contemporary challenge has been how trust law applies to complex financial or commercial arrangements. For instance, in the aftermath of the 2008 financial crisis, cases like Lehman Brothers International (Europe) v CRC Credit Fund [2012] UKSC 6 tested the boundaries of subject matter certainty. There, under regulatory rules, client monies held by an investment firm were intended to be held on trust for clients even if not segregated. The Supreme Court had to reconcile the principle of certainty of subject matter with the regulatory scheme. Ultimately, it was held that a trust did exist over the commingled client funds upon the firm’s insolvency (even if specific segregation hadn’t occurred initially), because the intention and the framework clearly identified a fund proportion for clients. While this was grounded in specific regulations, it shows the law’s adaptability – effectively, English law accepted a trust over a portion of a mixed fund for clients, akin in spirit to Hunter v Moss albeit in a different context. Such cases underscore that the courts are willing to enforce trusts in modern commercial settings, provided the substance of certainty is met (in Lehman, the proportionate entitlement of each client was identifiable by a formula, thus sufficiently certain subject matter).
In academic discourse, there have been calls to reconsider or clarify certain aspects of the three certainties. One recent scholarly argument is that we should recognise a “fourth certainty” – dubbed distributional certainty – as distinct from the traditional trio. Professor David Wilde, writing in 2020, suggests that where a trust requires dividing property among multiple beneficiaries, the law in effect demands certainty about how the property is to be divided (who gets what share) – and that this deserves explicit recognition separate from “subject matter” certainty or “objects” certainty. He notes that issues like those in Boyce v Boyce (discussed earlier) are often conflated with subject matter uncertainty, but in his view, distributional uncertainty has “differing consequences [and] special resolution techniques” and even ties into doctrines like administrative unworkability. Wilde points out that Knight v Knight itself, when Lord Langdale listed the certainties, mentioned the need for certainty in “the interests to be enjoyed by the objects” – hinting at this idea that not only must we know who the beneficiaries are, but what interest each beneficiary takes. This academic development does not change the law per se (the courts still analyse such issues under the established three headings), but it is a useful conceptual refinement. It reflects an effort by modern scholars to ensure that every aspect of trust validity is properly understood and that no gaps exist in the certainty analysis. While practitioners still speak of three certainties, the underlying requirement that beneficiaries’ shares be clear is acknowledged (often by the maxim that equity is equality if nothing else is specified). Whether courts will explicitly adopt a “fourth certainty” terminology is uncertain, but the discussion itself shows the depth of analysis contemporary trust law attracts.
Another modern discussion revolves around the distinction drawn in Hunter v Moss concerning intangible property. As noted, Hunter v Moss has critics who feel the law might need reform or clarification. Some have suggested that the decision should be revisited to require certainty of subject matter even for intangible assets, or that the law should provide a more coherent rationale (such as treating a trust of part of a fungible mass as a trust of a proportionate co-ownership share, which is one way to intellectually underpin Hunter v Moss). So far, English courts have not overturned Hunter, but they have also not extended its principle to obviously problematic scenarios (for example, it remains unclear if one could declare a trust of “500 out of my 1,000 identical gold bullion bars” without segregation – by analogy to shares one might argue yes, but gold bars are tangible so Hunter wouldn’t strictly apply, and likely London Wine would). Academic proposals to legislate on this point have not materialised, but this remains an area where future case law could further develop the certainty of subject matter doctrine, either by refining the rule or affirming the current approach.
In terms of law reform commissions or legislation, there has been little direct legislative intervention in the three certainties, largely because these are common law principles that have generally worked well. The Law Commission in England and Wales has not specifically proposed changes to the three certainties tests in recent reform programs; most trust law reforms in recent decades have focused on areas like trustees’ powers (e.g. Trustee Act 2000), perpetuities and accumulations (Perpetuities and Accumulations Act 2009), or the formalities for wills and dispositions (which intersect with trust creation but not the substantive certainty tests). One could argue the three certainties doctrine is a stable area of judge-made law that does not obviously demand reform. However, as trust law encounters new challenges – such as digital assets (cryptocurrencies or digital holdings) being held on trust, or the increasing use of trusts in international contexts – the courts will continue to adapt the interpretation of the certainties to new situations. For instance, ensuring certainty of subject matter when the asset is a type of cryptocurrency might raise novel questions (e.g. identifying particular crypto tokens on a blockchain for a trust). It is foreseeable that principles analogous to those used for shares will be applied, treating them as fungible intangibles.
Another recent practical development in the UK is not a change in the law of certainty, but in the oversight of trusts: the introduction of a Trust Registration Service (TRS) following anti-money laundering regulations. Now most express trusts, even private family trusts, must be registered with HM Revenue & Customs. While this does not affect whether a trust is valid (it’s an administrative requirement), it reflects the modern context in which trusts operate – transparency and accountability have increased. This indirectly pressures trustees and settlors to be clearer and more formal in setting up trusts, which likely means the classic pitfalls of uncertainty might be avoided more often with professional drafting. The historic cases of uncertainty often involved homemade wills or informal declarations; today, with greater regulation, settlors are more likely to seek legal advice, which helps ensure the three certainties are clearly satisfied in the trust instrument.
In conclusion, contemporary developments have largely confirmed the importance of the three certainties rather than undermined them. The fundamental requirement that a trust must have a clear intention, property, and beneficiaries remains as crucial in 2025 as it was in 1840. Courts have shown flexibility in applying these requirements to new scenarios – for example, relaxing object certainty for discretionary trusts, or accommodating trusts of non-segregated assets where it makes sense – but they have not abandoned the core principles. Academic commentary continues to critique and analyse the doctrine, proposing nuanced improvements such as explicitly recognising “distributional certainty”, yet these are evolutions in understanding rather than radical changes. In the absence of statutory overhaul, the common law of trusts demonstrates a continuity: the three certainties doctrine persists as a cornerstone of trust validity, ensuring trusts are created with the necessary clarity to be effective and enforceable.
Conclusion
The three certainties of trust law – intention, subject matter, and objects – are fundamental safeguards in English equity that ensure any trust is sufficiently defined to be operable and just. They require that the settlor’s intention to create a trust is unequivocal, that the property forming the trust is clearly identified, and that the beneficiaries (or purposes, if charitable) are certain so that the trust can be enforced. Through leading cases from Knight v Knight onward, the courts developed these principles to prevent trusts failing from ambiguity or poor drafting, while also preventing unfounded claims where no trust was truly intended. Each certainty addresses a different essential question: Intention asks, did the settlor mean to create a trust obligation? Subject matter asks, what property is committed to the trust, and in what shares? Objects asks, who are the beneficiaries (or permissible objects) of the trust? Only when all three answers are clear will equity recognise and enforce a trust.
We have seen how these certainties are applied with examples: precatory words like “in full confidence” without more do not suffice for intention, vague references to “the bulk” of an estate fail for subject matter uncertainty, and imprecise beneficiary classes like “friends” fail for object uncertainty. Conversely, the courts will uphold trusts where a reasonable interpretation yields certainty – as with Comiskey, where the will taken as a whole showed a clear trust intention; or Re Golay, where “reasonable income” was held objectively certain enough; or McPhail v Doulton, which liberalised the object certainty test so that a trust for employees and relatives could be workable by focusing on conceptual clarity. Equity’s flexibility is evident in its handling of the three certainties: the courts balance a respect for the settlor’s expressed wishes with a pragmatic insistence on clarity. Where a trust fails for want of certainty, the fallback doctrines (like resulting trust) ensure the property is returned to the settlor or estate, reflecting the principle that “equity will not assist a volunteer” in cases of an incomplete or uncertain gift.
In modern times, the three certainties continue to underpin trust drafting and litigation. The basic doctrine has not been replaced by statute, and attempts to soften it (such as allowing substantial compliance or “wait and see” approaches) have not been necessary because the courts have shown adaptability within the existing framework. Recent academic and judicial conversations have enriched our understanding – highlighting, for example, that within the traditional certainties we can further dissect issues like distribution among beneficiaries or evidentiary challenges in identifying a class – but these do not detract from the classic test. Any proposed reform would have to ensure that trusts remain defined enough to protect beneficiaries and trustees alike; so far, the common law has been up to the task. The clearest endorsement of the three certainties is their enduring presence in every law textbook and judgment on trusts: they are taught, cited, and applied as the starting point for analysing the validity of any express trust.
In conclusion, the three certainties in English trust law serve a crucial purpose by ensuring trust instruments are not void for indefiniteness. They represent a careful equilibrium: requiring clarity to prevent litigation and injustice, yet allowing enough flexibility for settlors to craft trusts in varied circumstances. Through incremental developments and case law, English law has kept the doctrine relevant in contemporary settings without legislative change. Trusts, being “creatures of equity”, continue to evolve, but the need for certainty – of intention, subject matter, and objects – remains a steadfast requirement. This ensures that trusts fulfill their role in law as intended, enforceable obligations rather than mere precatory or uncertain arrangements. The three certainties thus remain a cornerstone of trust law, combining historical wisdom with modern adaptability, and any future reform will likely build upon, rather than dismantle, this well-established doctrine.
References
Cases:
Burrough v Philcox (1840) 5 My & Cr 72, 41 ER 299.
Comiskey v Bowring-Hanbury [1905] AC 84 (HL).
Hunter v Moss [1994] 1 WLR 452 (CA).
Inland Revenue Commissioners v Broadway Cottages Trust [1955] Ch 20 (CA).
Knight v Knight (1840) 3 Beav 148, 49 ER 58.
Lambe v Eames (1871) LR 6 Ch App 597 (Ch).
McPhail v Doulton [1971] AC 424 (HL).
Midland Bank plc v Wyatt [1995] 1 FLR 696 (Ch).
Morice v Bishop of Durham (1805) 9 Ves 399, 32 ER 656.
Paul v Constance [1977] 1 WLR 527 (CA).
Re Adams and the Kensington Vestry (1884) 27 Ch D 394 (Ch).
Re Baden’s Deed Trusts (No 2) [1973] Ch 9 (CA).
Re Golay’s Will Trusts [1965] 1 WLR 969 (Ch).
Re Harvard Securities (in liquidation) [1997] 2 BCLC 369 (Ch).
Re Kayford Ltd [1975] 1 All ER 604 (Ch).
Re London Wine Co (Shippers) Ltd [1986] PCC 121 (Ch).
R v District Auditor ex parte West Yorkshire MCC [1986] RVR 24 (QB (Div Ct)).
Sprange v Barnard (1789) 2 Bro CC 585, 29 ER 320.
White v Shortall [2006] NSWSC 1379 (Supreme Court of NSW) (Aus).
Legislation:
Administration of Justice Act 1982, s.22 (UK).
Law of Property Act 1925, s.53(1)(b) (UK).
Books and Journal Articles:
Gary Watt (2019) Equity & Trusts Law Directions, 6th edn, Oxford University Press – Chapter 4 (Three Certainties) learninglink.oup.com.
Lewin on Trusts, 19th edn (2015) Sweet & Maxwell – para 3.005 (discussion of certainty of subject matter) centaur.reading.ac.uk.
Wilde, David (2020) “The three certainties required to declare a trust – or is it four? ‘Distributional certainty’.” Cambridge Law Journal 79(2): 349–359centaur.reading.ac.uk.
Palmer, Jessica & Rickett, Charles (2017) “The Revolution and Legacy of the Discretionary Trust.” Journal of Equity 11: 157–184 papers.ssrn.com.
Hudson, Alastair (2009) Equity and Trusts, 7th edn, Routledge-Cavendish – (comments on Hunter v Moss and certainty of subject matter) en.wikipedia.org.
Official / Web Sources:
HM Revenue & Customs (2021) Stamp Taxes on Shares Manual – “What is a trust?” (HMRC internal guidance) – Definition of a trust gov.uk.
Law Society (n.d.) “Trusts” – public guidance on what a trust is and the roles of settlor, trustee, beneficiary lawsociety.org.uk.
UK Government (2021) Trust Registration Service, Guidance (HMRC/Gov.uk) – (background on trust registration requirements, illustrating modern regulatory context).
