Licences and proprietary estoppel

Licences and proprietary estoppel sit at the fault-line between contract, property, equity and registration. The topic asks two deceptively simple questions. First, when is a person’s permission to use land merely personal, so that it binds only the grantor? Secondly, when does equity convert expectation, reliance and detriment into an interest capable of affecting successors to the land?

A licence is, in its orthodox form, not an estate or interest in land. It is authority to do on another’s land something which would otherwise be a trespass. The bare licence given to a dinner guest is revocable at will. A contractual licence is supported by contract: revocation in breach of contract may produce damages or an injunction, but it does not, merely for that reason, become proprietary. A licence coupled with an interest is parasitic on some independent proprietary right, for example a right to enter to take timber or minerals. A licence arising by estoppel is different again: the language of licence may describe the claimant’s occupation or use, but the enforceability comes from the equity generated by assurance, reliance, detriment and unconscionability.

Proprietary estoppel is the more important Tripos topic. It is a mechanism by which B acquires an equity against A where A has encouraged B to believe that B has or will obtain some right in relation to A’s land, B has acted on that belief, and it would be unconscionable for A to insist on strict legal rights. The modern cases resist rigid formulae: assurance, reliance and detriment are analysed together, with unconscionability as the controlling idea rather than a free-standing licence to do palm-tree justice.

The module context matters. Earlier weeks have dealt with the numerus clausus of legal interests, registration, overriding interests and overreaching. Those rules now explain the consequences of the conclusion that the claimant has only a personal licence or, instead, an equity by estoppel. The personal licence has no priority battle to fight because it is not proprietary. The estoppel equity, by contrast, is expressly recognised by section 116 of the Land Registration Act 2002 as an interest capable of binding successors in registered land, subject to priority rules. It may also be protected by actual occupation under Schedule 3 paragraph 2, though that requires the usual independent analysis of occupation and obviousness or knowledge.

In Cambridge supervision essays, the best answers do not say simply that licences are personal and estoppels are proprietary. They ask why the law draws that line. Contractual licences may generate serious expectations; proprietary estoppel may undermine formality requirements; and remedies now oscillate between satisfying expectations and compensating detriment, especially after Guest v Guest. Examiners reward answers which keep those tensions in view while remaining doctrinally precise.

The law of licences developed as the common law’s answer to a basic practical problem: landowners frequently permit others to enter or use land without intending to grant an estate. The licence therefore began as a negative concept. It was not a lease, not an easement, not a profit, and not an equitable interest. It simply made lawful what would otherwise be trespass. This explains both its utility and its limits. The guest at a house, the theatre-goer with a ticket, the contractor allowed onto a site, and the occupier under a preliminary agreement may all be licensees, but the licence itself does not carve an interest out of the land.

Nineteenth- and early twentieth-century authority generally insisted on this personal quality. The leading illustration is King v David Allen & Sons, where a contractual right to display advertisements on a wall did not bind a purchaser of the building. The House of Lords treated the arrangement as contractual permission, not a proprietary interest. That approach reflects the same structural concern as the closed list of recognised land rights: third parties should not be burdened by idiosyncratic personal arrangements unless the law recognises and protects them as proprietary.

The twentieth century then produced two kinds of pressure on the orthodox view. The first came from contractual licences used to protect residential occupation. In Errington v Errington and Tanner v Tanner the Court of Appeal protected licensees against arbitrary revocation where they had acted on family or domestic arrangements. Those cases are sometimes presented as if they made contractual licences proprietary. They did not. Their better reading is that, as between the parties, equity and contract prevented revocation contrary to the promise. Their importance is remedial and interpersonal, not a general abandonment of the licence’s personal character.

The second pressure came from equity. Courts had long intervened where a landowner stood by while another built on or improved land in the belief that he had rights. The older language was often that of acquiescence. Modern proprietary estoppel broadened the principle beyond passive standing by to active assurances, family understandings and informal inheritance promises. The farm cases, from Gillett v Holt to Thorner v Major and Guest v Guest, demonstrate the modern pattern: years of work, a representation that the land or business will come to the claimant, and a breakdown of family relationships.

Registration reform sharpened the question. Before the Land Registration Act 2002, the status of an equity by estoppel in registered land had to be inferred from general priority principles and the doctrine of overriding interests. Section 116 now declares that an equity by estoppel and a mere equity are interests capable of binding successors, though it does not tell us when the equity arises, what its content is, or how it ranks in every case. Those questions remain matters of equitable doctrine and priority analysis.

The history therefore supplies the central distinction. The law refused to allow contract alone to manufacture new proprietary burdens, but it allowed equity to intervene where conscience required. Proprietary estoppel is not a disguised contractual licence; nor is every disappointed licence-holder an estoppel claimant. It is a distinct equitable response to induced reliance concerning land.

1. A licence is permission, not property. The orthodox definition is functional: a licence authorises conduct on land which would otherwise be unlawful. It may arise gratuitously, by contract, or in connection with another interest. Its basic incidents are negative. It gives no estate, no exclusive possession as of right, no proprietary priority against purchasers, and no power to assign unless contractually permitted. This is why the lease/licence distinction from Week 8 remains essential. If the arrangement confers exclusive possession for a term at a rent, it is likely to be a lease unless special circumstances show otherwise. If it does not, the question becomes whether contractual or equitable enforcement is nevertheless available.

1. Bare licences are revocable, subject to reasonable time to leave. A bare licence is unsupported by consideration and unconnected to an interest. It is normally revocable at will. Once revoked, the licensee must be allowed a reasonable opportunity to depart or remove goods. The bare licence is of limited examination importance, but it provides the baseline against which contractual and estoppel-based claims are measured.

1. Contractual licences are enforceable inter partes. If A contracts with B that B may occupy or use land, A’s attempted revocation may be a breach of contract. The court may award damages or, where appropriate, grant an injunction or specific relief. But the contractual licence does not thereby become an interest in land. The critical distinction is between enforceability against the grantor and enforceability against successors. The former is a matter of contract and remedies. The latter requires property, trust, agency, fraud or estoppel. King v David Allen and Ashburn Anstalt v Arnold are the anchor cases.

1. A licence coupled with an interest is different because the interest is proprietary. Where a licence is necessary to enjoy an independent proprietary right, the licence may be irrevocable for so long as the interest subsists. The right to enter land to take minerals under a profit, or to remove goods sold, is not proprietary because it is called a licence. It is protected because there is an underlying property or contractual interest to which entry is ancillary.

The leading cases form two lines which should not be collapsed. The first concerns licences and the refusal to make them proprietary merely because they are contractual. King v David Allen & Sons is the orthodox starting point. A cinema owner promised the claimant the right to post advertisements on a wall. The owner later leased the building to another. The House of Lords held that the advertising agreement did not bind the lessee. The claimant had contractual rights against the promisor, not an interest in the land.

Errington v Errington is more subtle. A father bought a house for his son and daughter-in-law, promising that if they paid the mortgage instalments the house would be theirs. After his death, the personal representatives sought possession. The Court of Appeal restrained revocation while the couple continued to perform. The case is often over-read. It does not prove that contractual licences are proprietary; it shows that a licence may be irrevocable between relevant parties where unilateral contractual or equitable considerations make revocation unjust.

National Provincial Bank v Ainsworth is not a licence case in the narrow sense but is indispensable. The House of Lords held that a deserted wife’s right to remain in the matrimonial home was not a proprietary interest binding the bank. Lord Wilberforce’s criteria for property continue to haunt the topic: a right must be sufficiently definite, identifiable and stable before land law can treat it as proprietary.

Ashburn Anstalt v Arnold reasserted orthodoxy after a period of doctrinal uncertainty. The purchaser of commercial premises had notice of an occupier’s contractual right to remain until redevelopment. Fox LJ rejected the notion that a contractual licence binds third parties merely because they take with notice. Binding effect may arise through established doctrines, such as constructive trust in exceptional cases, but not through notice alone.

The proprietary estoppel line begins with cases such as Pascoe v Turner and Gillett v Holt, where assurances about homes or farms induced significant detrimental reliance. The modern shape is given by Cobbe, Thorner, Jennings and Guest. Cobbe marks the limit: equity will not normally enforce an incomplete, subject-to-contract commercial negotiation between sophisticated parties. Thorner demonstrates contextual assurance in domestic and agricultural life. Jennings emphasises proportionality in relief. Guest is now the leading remedial authority: expectation is a powerful starting point, but relief must not exceed what is necessary to prevent unconscionability.

For examination purposes, the most important comparison is Cobbe and Thorner. Both involved expectations about land; only one succeeded. The difference lies in clarity, context and formal risk. In Cobbe, both parties knew that no binding contract existed and that the arrangement required formal completion. In Thorner, the claimant reasonably understood, over many years, that he would inherit the farm. Proprietary estoppel protects reliance induced by assurance; it does not rescue every failed negotiation.

See practice questions section below.

See further reading section below.