JUST when the death of free acceptance as an unjust factor seemed assured, it has returned like a zombie to plague the law of unjust enrichment. In Barton v Morris [2023] UKSC 3, [2023] A.C. 684, at [230], Lord Burrows had expressly rejected free acceptance as an unjust factor, albeit in a dissenting judgment, and considered that failure of consideration, now commonly known as failure of basis, should be used instead. Recently, three decisions of the High Court have considered free acceptance as an unjust factor. In two it was recognised (Rogers v Wills [2025] EWHC 1367 (Ch), [2025] 1 W.L.R. 4995 and Jones v Griffiths [2025] EWHC 797 (KB) (albeit not established in the latter)) and in one it was rejected (H and P Advisory Ltd. v Barrick Gold (Holdings) Ltd. [2025] EWHC 562 (Ch), [2025] 1 W.L.R. 4919). These decisions reveal significant confusion about the function of unjust factors and the operation of failure of basis.

Free acceptance is clearly relevant when establishing enrichment, since it defeats the defendant’s subjective devaluation of a benefit received. Where the defendant received a service, knowing that the claimant expected to be paid for it and had an opportunity to decline it but failed to do so, the defendant cannot assert that they did not value the service. But should this also be sufficient to establish that the defendant’s receipt of the service was unjust? In Rogers v Wills HHJ Paul Matthews held that it was. In H and P Advisory Ltd. Simon Gleeson, sitting as a Deputy Judge of the High Court, held that free acceptance was not a free-standing unjust factor but formed part of failure of basis. The crucial difference between free acceptance and failure of basis is that, for the latter, there needs to be a shared understanding between the parties that the claimant’s provision of a benefit was subject to a condition and that condition has failed, whereas for the former no such understanding is required, the focus is on the defendant’s failure to reject the service knowing that it was not provided gratuitously.

Rogers v Wills concerned a claim by a daughter against her mother’s estate for the cost of caring for her mother in her final years. It was found that there had been a contract between the mother and daughter, but, if he was wrong, the judge also considered liability in unjust enrichment. He concluded that, assuming no contract, there was no shared assumption of payment as a condition for the provision of care, so failure of basis could not be established. This was because, if there had been such a shared basis, there would have been a contract. Instead, he held that the mother had freely accepted the care having had the opportunity to decline it whilst knowing that the daughter expected to be paid for the care she had provided.

HHJ Paul Matthews considered that he was bound by a number of authorities to recognise free acceptance as an unjust factor. In H and P Advisory Ltd. Simon Gleeson had preferred to analyse these cases as recognising failure of basis. This analysis of the authorities, some decided when unjust enrichment had not been recognised, reveals little other than that there is a fine line between failure of basis and free acceptance, turning on whether a shared assumption can be established.

More significantly in Rogers v Wills was the justification for the recognition of free acceptance as an unjust factor, namely that, where the recipient realises that a service is being conferred with the expectation of payment, they are subject to a moral duty to reject the service (at [232]). This moral duty within free acceptance involves the imposition of liability for an omission, which should only arise where the duty is clearly defined, which it is not. Further, the duty arises even if the defendant was unaware of the expectation of payment but “should have known” (at [233]). It follows that an obligation to make restitution can be imposed because the recipient should have rejected the service even if they were unaware that the provider expected to be paid for it.

The judge justified his recognition of this moral duty, a duty the recognition of which was not grounded on any theory but only assertion, with reference to a hypothetical window cleaner example. A mistakenly cleans the windows of B’s house when A should have cleaned the windows of another house. B returns home just as A starts work, sees what is happening, is aware that A expected to be paid, but does not object. The judge considered that B should be liable to pay for the service provided by A. This is probably correct, but for different reasons. B has freely accepted the service, such that B cannot subjectively devalue the benefit. This enrichment is unjust, but because of A’s causative mistake not free acceptance. In HHJ Paul Matthews’s world, if I stop my car at traffic lights and somebody jumps from the kerb to wash my windscreen, I am under a moral duty to say no. If I do not, I will be required to pay for the privilege (subject to any possible defence of risk-taking which presumably negates the moral duty, although this was not considered). The imposition of a liability in such circumstances is contrary to the general tenor of unjust enrichment jurisprudence and resorting to vague assertions of “moral duty” is not sufficient to justify it.

In the earlier case of H and P Advisory Ltd. Simon Gleeson rejected free acceptance and focused instead on failure of basis. The claimant investment bank had done considerable work on a proposed merger which eventually took place between two gold mining companies. It was found that no contract had been made between the parties. It is common practice for investment banks to do such work on an unpaid basis in the hope that they will secure appointment subsequently. This work had conferred a valuable benefit and it was found that the parties to the merger had recognised this and had intended to make some payment in respect of the services received. The key question was whether an unjust factor could be identified to ground a claim in unjust enrichment for a quantum meruit remedy.

Whilst rejecting free acceptance as a free-standing unjust factor, the judge considered that receipt of a service knowing that the provider expected to be paid for it constitutes an ingredient of failure of basis since, with this knowledge, there will be a shared assumption such that, if the claimant is not paid, the basis will have failed. This is illustrated by the facts of H and P Advisory Ltd. itself. There had been a conversation between the claimant and the two companies where it was clear that the claimant believed it would be appointed as adviser and the companies had the opportunity to disabuse the claimant but had failed to do so. This established a common basis of understanding that the claimant would be appointed and would be paid for their work, objectively determined. The claimant was not appointed and was not paid so the basis had failed entirely. This appears to reinstate free acceptance. Indeed, as the judge acknowledged (at [263]), if the recipient does not intend to pay for the service in circumstances where they know or ought to know that the provider expected payment, the recipient is at risk of being liable to pay if they do not make clear that they do not intend to pay. Here, the awareness of an expectation of payment is being used to establish a common assumption of payment, but this looks a lot like free acceptance. This could be more clearly distinguished from free acceptance if the identification of the basis turned on what the defendant actually knew rather than what they should have known.

There are three other significant observations about the approach adopted by Simon Gleeson. First, the basis may be established after the services had started to be provided such that, if the basis fails through no contract being made, the claimant can recover their value, as long as there was a close connection between the service and the shared assumption of payment, such as where it was all part of the same transaction.

Second, there was an analysis of risk-taking which, if correct, suggests that the defence of risk-taking will not be available in cases involving failure of basis. The claimant had taken a risk that no contract would be made but, because of the identification of a basis between the parties, the judge considered that this was a risk which had paid off, meaning that the claimant was a “gratified risk-taker” rather than a “disappointed risk-taker”. In fact, the claimant was disappointed as regards the risk that a contract would not be made, but gratified once a basis could be identified which had failed resulting in restitution of the value of the service. It follows that, once the shared assumption is established, the claim cannot be defeated by the claimant’s being a risk-taker. But this means that risk-takers are rewarded which undermines the rationale for recognising a risk-taking defence in the first place and is one of the key reasons why free acceptance should not be recognised as an unjust factor.

Third, there are concerns about the contract/unjust enrichment borderline. In Rogers failure of basis was held to be incompatible with the assumption that no contract had been made. This was not the case in H and P Advisory Ltd. Perhaps the difference is due to the distinct family and commercial contexts. It follows that, in the commercial context if no formal contract has been made, it remains possible to impose restitutionary liability if a shared assumption that a contract would be made can be identified. Whilst this is a non-contractual liability it comes very close to contract. Judges will need to tread very carefully to ensure that the identification of a shared assumption does not undermine the finding of no contract.

We are left with disagreement in the High Court about the continued relevance of free acceptance to the law of unjust enrichment. This needs to be resolved by a higher court. In doing so free acceptance as an unjust factor should be killed off for good. Failure of basis is a justifiable unjust factor, but there is still work to be done to clarify its operation and ambit and to ensure that it retains a theoretical and evidential distinction from free acceptance, otherwise free acceptance will continue to plague the law.