Neutral Citation Number: [2013] EWCA Civ 1415
Case No: A3/2013/0921
IN THE COURT OF APPEAL (CIVIL DIVISION)
ON APPEAL FROM THE HIGH COURT OF JUSTICE
CHANCERY DIVISION
HIS HONOUR JUDGE PELLING QC
[2013] EWHC 772 (Ch)
Royal Courts of Justice
Strand, London, WC2A 2LL

Date: Thursday 14th November 2013
Before :

LORD JUSTICE BEATSON
LORD JUSTICE FLOYD
and
SIR STANLEY BURNTON
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Between :

	TFL Management Services Ltd	Appellant	
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	Lloyds Bank PLC
(Formerly known as Lloyds TSB Bank PLC)	Respondent	
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 (Transcript of the Handed Down Judgment of
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Christopher Harris (instructed by Charles Fussell & Co LLP) for the Appellant
Gerard McMeel and Neil Levy (instructed by CMS Cameron McKenna) for the Respondent
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Judgment
Lord Justice Floyd : 
1.	A spends money seeking a judgment for the recovery of a debt from B.  A fails to recover the debt because, so the court holds, the debt is not in fact owed by B to A (as A mistakenly thought), but owed by B to C.   C then recovers the debt, relying on the judgment in A’s unsuccessful claim.  The question raised in this appeal is whether A has a claim based on unjust enrichment against C, enabling him to recover the money expended on obtaining the judgment. 
2.	In an order dated 28 February 2013, His Honour Judge Pelling QC, sitting as a judge of the High Court, summarily dismissed the claim of TFL Management Services Ltd (“TFL”) against Lloyds TSB Bank PLC (“the Bank”). Summary judgment in favour of the Bank was entered on the ground that, assuming the facts to be as pleaded by TFL, it could not succeed. This, the judge found, was because any benefit conferred on the Bank was an “incidental benefit” and incidental benefits did not found a claim in unjust enrichment. TFL appeals against that order with permission of Aikens LJ.
3.	The assumed facts can be summarised as follows. The underlying dispute concerned the entitlement of a company, The Trading Force Ltd (“TTF”), to commission from Hesco Bastion Ltd (“Hesco”) in respect of sales of “gabions”.  Gabions are gigantic bags used for filling with earth or other local materials and then used for fortification and military engineering.  TTF and Hesco entered into a general agency agreement in 1995 and in 1998 a specific one relating to supplies to the United States Defense Supply Centre Columbus, Ohio (“the general agency” and “the DSCC agreement” respectively).  The Bank was the holder of a debenture on TTF’s assets and, on 10 April 2002, appointed administrative receivers over it pursuant to its charge.  On 30 April 2002, by means of a Chargee Sale of Assets Agreement (“the CSA agreement”) the receivers assigned the assets of TTF, including the “marketing contracts” and “sale contracts” but excepting defined “retained assets”, to Explora Group Ltd (“Explora”). The “marketing contracts” and “sale contracts” included TTF’s contracts with named parties, including Hesco, and therefore the general agency and the DSCC agreement. But, by sub-paragraph (c) of the definition of “retained assets” in the CSA agreement, “book debts” qualified as “retained assets”. 
4.	Over the next fourteen and a half months, there were exchanges between Explora and Hesco, TTF went into liquidation, Explora became a public limited company, TTF, acting by its receivers, issued proceedings against Hesco claiming an account of what was due to it from Hesco and, on 13 June 2003, Explora issued proceedings for commission payable by Hesco in respect of all contracts entered into by Hesco with TTF from 30 April 2002 (the “Explora v Hesco proceedings”). In early 2004, TTF was joined as a second defendant to the Explora v Hesco proceedings, but took no active part in the proceedings until after the substantive hearing of the appeal to the Court of Appeal.
5.	On 28 July 2004 Simon J held ([2004] EWHC 1863 (QB)) that the purported assignment of the two agreements to Explora amounted to repudiatory breaches of those agreements, which Hesco was entitled to and did terminate on 14 June 2002, but that termination did not affect TTF’s accrued rights to commissions before that date and that accrued right was validly assigned to Explora.  Explora was, accordingly, entitled to commissions in respect of sales made between the date of the assignment and the expiry of the agreements. 
6.	On the ensuing appeal, the Court of Appeal identified 10 issues which arose between Hesco as principal and Explora as assignee.  Issue 8(a) was whether TTF’s right to commission was assigned to Explora under the CSA agreement, or whether it was retained by the receivers of TTF. In a judgment handed down on 20 July 2005, the Court of Appeal ([2005] EWCA Civ 646) held that Explora was not entitled to commissions under the DSCC agreement at all, and was only entitled to commission under the general agency in respect of commissions falling due after 30 April 2002.  Under the terms of the assignment by the receivers to Explora, the right to commissions under the DSCC agreement had accrued at the date of that agreement, so all the rights to those commissions qualified as “book debts” and therefore were covered by the exclusion from the assignment of “retained assets”. 
7.	Hesco’s appeal was therefore, in substance, allowed.  Explora was, however, granted a declaration that it was entitled to commissions on non-DSCC orders arising from enquiries after 30 April 2002 (the date of the assignment) and before 14 June 2002 (the date of termination) and an account and payment of commissions due.   The Court of Appeal directed that “any claim which [TTF], acting by its Receivers or Liquidator, may wish to bring against Hesco as a result of the judgment … shall be dealt with by the Commercial Court” and made certain directions as to how any such claim should proceed. The receivers of TTF were represented at the hearing after judgment and made an application for the costs of a hearing on 15 July 2005, before judgment was handed down: those costs were reserved to the Commercial Court. 
8.	The Court of Appeal also made orders for costs as between Explora and Hesco.  No order for payment of any costs was made either in favour of or against TTF.  Further, it does not appear that any application was made by Explora for its costs against the receivers.  Explora say, but the Bank does not admit, that Explora’s costs of the Explora claim were £550,000 exclusive of VAT.
9.	Following the decision of the Court of Appeal and pursuant to the directions given in its order, the receivers of TTF issued proceedings in the Commercial Court against Hesco.  Ultimately, in February 2008 the receivers settled the claim in return for payment of £1,182,861.20 from Hesco and payment of their costs.  Pursuant to their debenture the Bank recovered those funds.  
10.	On 2 April 2007 Explora went into administration.  On 17 March 2008 Explora assigned certain rights, including a claim to rectify the CSA agreement to Almajmou’a Alistikahafieh Liltijara Ltd (“AAL”).  On 28 March 2008 Explora went into creditors’ voluntary liquidation.
11.	In July 2011 further assignments of Explora’s rights took place.  These included an assignment to AAL of Explora’s right to bring claims against the Bank, and an assignment by AAL to TFL, the claimant in this action, of that right.  TFL, as assignee of Explora’s rights, commenced this action against the Bank on 11 July 2011.
12.	TFL’s pleaded claim against the Bank includes a claim for breach of the CSA agreement.  It is common ground that the contract claim will go to trial and we are not concerned with it on this appeal, save to the extent that we should be conscious that summary dismissal of the unjust enrichment claim will not bring the proceedings to an end unless it provokes a settlement. The unjust enrichment claim, again as pleaded, is based on the following main factual allegations:
i)	Throughout the Explora v Hesco proceedings Explora mistakenly believed that the benefit of the agreements with Hesco had been assigned to Explora;
ii)	At all material times the Bank (and/or the receivers as agents for the Bank) mistakenly believed that the benefit of the agreements with Hesco had been assigned to Explora;
iii)	Because of the “mutual mistake” Explora incurred the costs of the Explora v Hesco action in the sum of £550,000.
iv)	Accordingly Explora conferred a valuable benefit on the Bank and the Bank was unjustly enriched at the expense of Explora.
The judgment
13.	The core of the reasoning of HHJ Pelling QC can be summarised as follows.  He recorded the submission of counsel for Explora that the “benefit” which had enriched the Bank was either the final and binding judgment of the Court of Appeal which created an issue estoppel as between Hesco and at least the receivers of TTF or, in the alternative, the legal costs which Explora had expended, as these were costs which the Bank would otherwise have had to spend to recover the book debts.  He then recorded the fact that the Bank accepted in principle that the provision of services that conferred an incontrovertible benefit was capable of amounting to the necessary enrichment.  However, the judge went on to say that there were limits to that principle.  Relying on Ruabon Steamship Ltd. v London Assurance Company Limited [1900] AC 6; Becerra and another v Close Brothers Corporate Finance Ltd. (unreported 25 June 1999); Goff & Jones: The Law of Unjust Enrichment (8th Edition) at paragraphs 4.52 and 4.53; and Burrows: A Restatement of the Law of Unjust Enrichment (2012) at paragraph 8(4), he concluded that there was a rule that “incidental benefits”, which the benefit to the Bank was an example of, do not support a claim in unjust enrichment.  
14.	Basing himself on these authorities, the judge concluded that Explora’s claim was unarguable, whether put on the basis of the legal fees which the Bank would otherwise have to spend, or on the basis of the obtaining of a judgment creating an issue estoppel between the Bank or its agents (the receivers) and Hesco.  It was inescapable that the Explora claim was for the benefit of Explora not the Bank, for the protection of Explora’s interests not the Bank’s interests, and for the purpose of obtaining a result which would have provided no benefit to anyone other than Explora.
15.	The judge rejected a submission made by counsel for Explora that, unlike the present case where the court had to assume that there had been a mistake, the authorities relied on were not cases of mistake at all.  The judge pointed out that the mistake in the present case was not one which the Bank or the receivers had encouraged Explora to make, or in respect of which they stood by, knowing that it was being made. If that had been the position, Explora’s position would have been arguable.
16.	Finally, the judge rejected a submission that there had in fact been no mistake, as Explora must be taken to have appreciated that the “book debts” issue might be resolved against it, and had assumed that risk.  He thought there was some force in this point, but considered it could only be resolved at trial.  
17.	The judge decided that if he was wrong about the incidental benefit point, none of the other answers proffered by the Bank to the unjust enrichment claim was sufficiently decisive to enable him to dismiss the claim summarily.  All of these answers are sought to be revived by the Bank’s respondent’s notice on this appeal. 
The arguments on the appeal
18.	The first question in the appeal is whether the judge was right to hold that the restitutionary claim must inevitably fail because any benefit conferred on the Bank was an “incidental benefit”, and incidental benefits cannot form the basis of a claim for unjust enrichment. 
19.	TFL does not dispute that there is a defence of “incidental benefit”.  It submits, however, that the defence requires proof of two distinct benefits, and there are no such distinct benefits here.  The present case was a case of a single benefit, because the book debts either belonged to Explora or the receivers, and thus the benefit of the legal work or the Court of Appeal judgment could only be for Explora or for the receivers (and thus the Bank).
20.	TFL also submits that the judge was wrong to hold that, absent a mistake induced by the Bank or the receivers, or “standing by” by them, exclusive self interest was an answer to the unjust enrichment claim.
21.	Explora finally submits that the judge should not have determined the application on assumed facts. Given the uncertainty of the law and the unusual features of the case, he should have let the matter go to trial. 
22.	The Bank supports the judge on all points.  On its behalf Mr McMeel submits that the authorities relied on by the judge do make it possible to articulate a clear exception in the case of “incidental benefit”.  He submitted that it arose where:
i)	The claimant had embarked on an action or course of actions with some principal intended consequence in mind;
ii)	The intended consequence of the action or course of actions was pursued in the claimant’s self interest;
iii)	A benefit accrues to the defendant which is not identical to the principal intended consequence.
23.	Here, the Bank submits, Explora pursued the litigation against Hesco with the recovery of the commissions as its principal intended consequence.  It did so in its self-interest.  The benefit which accrued to the Bank or the receivers was entirely different from the principal intended consequence.  Indeed Explora’s efforts were directed at establishing that the commissions belonged to Explora, whilst the benefit to the Bank is that they belong to the Bank.  Explora cannot recover by claiming as a benefit to the Bank something which it was striving so assiduously to prevent. 
24.	In a following argument, Mr Levy submitted that the judge was perfectly entitled to decide the matter on the assumed facts.  He referred us to passages from the Lord Woolf’s interim report “Access to Justice”, Jackson LJ’s “Preliminary Report on Civil Litigation Costs”, and the more recent  “Chancery Modernisation Review” under Briggs LJ.   These, he submitted, pointed towards a more ready use of summary procedures to remove road blocks to compromise.
25.	By their Respondent’s notice the Bank seeks to advance the alternative arguments for summary dismissal of the claim which the judge rejected.  I will summarise these, if necessary, when I have considered Explora’s appeal on incidental benefit.
The approach to summary judgment
26.	The judge referred to Easy Air Limited v Opal Telecom Limited [2009] EWHC 339 (Ch) as setting out the approach under CPR 3.4(2)(a) and 24.2.  In that case Lewison J (as he was then) said:
“ .. the court must be careful before giving summary judgment on a claim. The correct approach on applications by defendants is, in my judgment, as follows: 
i) The court must consider whether the claimant has a "realistic" as opposed to a "fanciful" prospect of success: Swain v Hillman [2001] 1 All ER 91;
ii) A "realistic" claim is one that carries some degree of conviction. This means a claim that is more than merely arguable: ED & F Man Liquid Products v Patel [2003] EWCA Civ 472 at [8];
iii) In reaching its conclusion the court must not conduct a "mini-trial": Swain v Hillman;
iv) This does not mean that the court must take at face value and without analysis everything that a claimant says in his statements before the court. In some cases it may be clear that there is no real substance in factual assertions made, particularly if contradicted by contemporaneous documents: ED & F Man Liquid Products v Patel at [10];
v) However, in reaching its conclusion the court must take into account not only the evidence actually placed before it on the application for summary judgment, but also the evidence that can reasonably be expected to be available at trial: Royal Brompton Hospital NHS Trust v Hammond (No 5) [2001] EWCA Civ 550;
vi) Although a case may turn out at trial not to be really complicated, it does not follow that it should be decided without the fuller investigation into the facts at trial than is possible or permissible on summary judgment. Thus the court should hesitate about making a final decision without a trial, even where there is no obvious conflict of fact at the time of the application, where reasonable grounds exist for believing that a fuller investigation into the facts of the case would add to or alter the evidence available to a trial judge and so affect the outcome of the case: Doncaster Pharmaceuticals Group Ltd v Bolton Pharmaceutical Co 100 Ltd [2007] FSR 63;
vii) On the other hand it is not uncommon for an application under Part 24 to give rise to a short point of law or construction and, if the court is satisfied that it has before it all the evidence necessary for the proper determination of the question and that the parties have had an adequate opportunity to address it in argument, it should grasp the nettle and decide it. The reason is quite simple: if the respondent's case is bad in law, he will in truth have no real prospect of succeeding on his claim or successfully defending the claim against him, as the case may be. Similarly, if the applicant's case is bad in law, the sooner that is determined, the better. If it is possible to show by evidence that although material in the form of documents or oral evidence that would put the documents in another light is not currently before the court, such material is likely to exist and can be expected to be available at trial, it would be wrong to give summary judgment because there would be a real, as opposed to a fanciful, prospect of success. However, it is not enough simply to argue that the case should be allowed to go to trial because something may turn up which would have a bearing on the question of construction: ICI Chemicals & Polymers Ltd v TTE Training Ltd [2007] EWCA Civ 725.
27.	Neither side sought to challenge these principles.  I would add that the court should still consider very carefully before accepting an invitation to deal with single issues in cases where there will need to be a full trial on liability involving evidence and cross examination in any event, or where summary disposal of the single issue may well delay, because of appeals, the ultimate trial of the action: see Potter LJ in Partco v Wragg [2002] EWCA Civ 594; [2002] 2 Lloyds Rep 343 at 27(3) and cases there cited.  Removing road blocks to compromise is of course one consideration, but no more than that.  Moreover, it does not follow from Lewison J’s seventh principle that difficult points of law, particularly those in developing areas, should be grappled with on summary applications; see Partco at 28(7).  Such questions are better decided against actual rather than assumed facts.  On the other hand it may be possible to say that the trajectory of the law will never on any view afford a remedy: see for example Hudson and others and HM Treasury and another [2003] EWCA Civ 1612.  
Incidental benefit
28.	Neither Explora’s nor the Bank’s formulation of a rule precluding recovery of an incidental benefit in a claim for unjust enrichment derives from any English authority.  The Bank’s formulation is not to be found in terms even in the judgment of HHJ Pelling QC. Both sides are inviting this court to formulate for the first time, on this summary judgment appeal, an exception to the type of benefit which, if conferred on a defendant by a claimant, can be relied on for the purposes of an unjust enrichment claim.  
29.	Before undertaking the formulation of an “incidental benefit” exception it is necessary to set out the basic elements of an unjust enrichment claim.  The parties are agreed that, in general, in considering a claim for unjust enrichment four primary questions must always be considered, namely:
i)	Has the defendant benefited or been enriched?
ii)	Was the enrichment at the expense of the claimant?
iii)	Was the enrichment unjust?
iv)	Is there any specific defence available to the defendant such as change of position?
These are the questions posed by Lord Steyn in Banque Financiere de la Cite v Parc (Battersea) Limited [1999] 1 AC 221 at 227 A to B; see also per Lord Hoffmann at 234 C-D (“BFC”).  However, as Henderson J pointed out in Investment Trust Companies v HMRC [2012] EWHC 458 (Ch):
“the four questions are no more than broad headings for ease of exposition. They should not be approached as if they have statutory force.”  
30.	“Incidental benefit” is undoubtedly a concept acknowledged by academic writers.  Thus at paragraph 4-52 in Goff & Jones: Law of Unjust Enrichment 8th Edition the authors say:
“No claim lies in unjust enrichment to recover the benefits which are incidentally conferred on a defendant by a claimant in the course of acting in his own interest”.
31.	This broad statement, which relies on a statement by Lord Halsbury in Ruabon Steamship Ltd. v London Assurance Company Limited [1900] AC 6 (see below) needs to be understood in the context of  the commentary which follows:
“This rule does not deny that the defendant is enriched by the receipt of incidental benefits, but withholds restitution for other reasons.  Some of the cases may be explained on the basis that the benefit received by the defendant was not one to which the claimant was exclusively entitled, so that the benefit was not received at his expense.  Alternative explanations are either that the claimant abandoned the benefit received by the defendant, or that the defendant’s enrichment is not unjust because a claimant who chooses to pursue a course of action for his own purposes that he knows must incidentally benefit the defendant, intends that outcome although it is not his primary motivation.”
32.	Thus the authors are explaining that the rule is not about the first of Lord Steyn’s questions in BFC “has the defendant benefited or been enriched?”.  The rule assumes this. They suggest that the rule may provide a negative answer to the second question “was the enrichment at the defendant’s expense?” or the third question “was it unjust?”.  Alternatively it may be a specific defence based on abandonment.  This already impressive array of possible rationales for the rule suggests that it may be better to consider cases against the questions in BFC, rather than seeking to formulate a general exception based on characterisation of the nature of the benefit alone.
33.	In Burrows: A Re-statement of the English Law of Unjust Enrichment (2012), Professor Burrows proposes a rule at paragraph 8(4):
“Even if the benefit obtained by the defendant is directly from the claimant, the enrichment is generally not at the claimant’s expense if the benefit is merely incidental to the furtherance by the claimant of an objective unconnected with the defendant’s enrichment.”
34.	So stated, the rule provides a negative answer to the second BFC question.  However Professor Burrows also says, in the relevant passage of commentary, that there are no clear authorities in English law which support the existence of such a rule. He goes on to point out that the examples given to support the rule are usually ones where there is, in any event, no unjust factor, that is to say the examples provide a negative answer to the third BFC question.  This shows again, to my mind, that the existing conceptual structure explained in BFC is likely to be adequate for most, if not all, purposes.   
35.	The Restatement and other academic writings contain a number of hypothetical examples used to illustrate the incidental benefit rule.   One example, also commented on by Professor Birks (see Birks: Unjust Enrichment 2nd Edition 2005 at 158-160), is of a person heating her own flat and incidentally providing a level of heating to the flat above. Commentators are agreed that there is no entitlement to restitution even if the claimant is mistaken, thought the heating was free and would not otherwise have turned it on.  The benefit remains merely incidental to the claimant heating her own flat. 
36.	Nobody would quarrel with that result.  The heating of the flat above was the entirely foreseeable consequence of heating the flat below.  The owner of the lower flat must be taken to have accepted this as an inevitable consequence of turning on her own heating.  Her remedy lies in insulation not restitution.    Professor Birks explains the example on the basis that there was a gift of the benefit, a yet further rationalisation of the supposed rule.    
37.	These academic writings make it abundantly clear that although “incidental benefit” may be a convenient chapter heading or umbrella term, it includes within its scope a whole variety of cases which may perhaps be better explained by reference to one or more of the questions asked in the BFC case.  
38.	The judge drew support from the decision of the House of Lords in Ruabon Steamship Ltd. v London Assurance Company Limited [1900] AC 6.  The respondent insurer in that case was liable for the damage suffered by a ship, the Ruabon, sustained on a voyage.  The respondent arranged for the necessary repairs to be effected in a dry dock.  While the vessel was in the dry dock at the insurer’s expense, the owners arranged for the ship to be inspected for the purposes of its Lloyd’s classification.  The insurer sought a contribution from the owner towards the cost of dry docking on the basis that the insurer had been saved the expense of arranging dry docking for the purposes of the Lloyd’s classification.  The House of Lords rejected the claim.  Lord Halsbury said this:
“I cannot understand how it can be asserted that it is part of the common law that where one party gets some advantage from the act of another a right of contribution towards the expense of that act arises on behalf of the person who has done it.  Many cases might be put where the generality of such a proposition would be plainly contrary to any received principle, and to my mind the question now in debate – admitted to be absolutely novel – would not be covered by any principle known to the law, except such a general proposition as I have indicated above.”
39.	The House of Lords in Ruabon Steamship was not looking at the case through the eyes of the modern law of unjust enrichment.  Had it been doing so, their Lordships would have had to go on to ask whether the owner had been enriched at the expense of the insurer, whether the owner’s enrichment was unjust and whether the owner had any specific defences.  As it was, the insurer was forced to rely on a principle of obviously unsustainable width, and its claim was bound to fail.  The case is of limited assistance in formulating a rule about “incidental benefit” in the modern law of unjust enrichment.  The very general terms in which the incidental benefit rule is expressed in the passage from Goff & Jones at paragraph 4-52, relying on Ruabon, must be seen in that light. 
40.	The judge also referred to Becerra and another v Close Brothers Corporate Finance Ltd. (unreported 25 June 1999) a decision of Thomas J (as he then was) at first instance.  In that case a Mr Page (acting with Mr Becerra) had learned of the proposed sale conducted by Close Brothers of the betting shop business of William Hill by Brent Walker.  Mr Page had contacted Close Brothers offering his services in contacting potential bidders in Asia, and Nomura.  Close Brothers made clear that he could do so, but if he did, he would be “acting off his own bat”.  Mr Becerra contacted someone he knew at Nomura and introduced him to Close Brothers.  When the transaction completed between Brent Walker and Nomura, the claimants sought a commission.  Thomas J rejected the claim.  His reasoning is apparent from the following:
“As I have come to the conclusion of fact that the plaintiffs were not requested by Close Brothers to perform any service for them and their overwhelmingly dominant motivation was their own self-interest if not their sole motivation, then it is clear they cannot recover, as [counsel for the claimants] accepted would be the case if I made such a finding”
41.	The case thus proceeded on the basis of a concession.  Given that the claimants in that case were being told that if they pursued the matter they would be acting off their own bat, and not as agents for Close Brothers, it would in no sense be unjust for them to be denied a remedy in restitution. Again therefore, it is possible to explain Becerra in terms of the questions asked in BFC. 
42.	The judge found assistance in Becerra because of its concentration on self-interest.  As I have said, he did not think that the fact that the claimant in the present case was acting under a mistake was a basis for distinguishing Becerra or Ruabon Steamship.  However, in Greenwood v Bennett [1973] 1 QB 195, a Mr Harper, a garage mechanic, bought a Jaguar car from a rogue who had stolen it and wrecked it in an accident.  He expended money on repairing it in the belief that he owned it.  The car was repossessed by the true owner.  The Court of Appeal held that Mr Harper had a restitutionary claim for the value of the repairs.  Lord Denning said this:
“Upon what principle is this to be done?  [Counsel] has referred us to the familiar cases which say that a man is not entitled to compensation for work done on goods or property of another unless there is a contract express or implied, to pay for it.  We all remember the saying of Pollock C.B.: “One cleans another’s shoes; what can the other do but put them on?”: Taylor v Laird (1856) 25 L.J. Ex. 329,332.  That is undoubtedly the law when the person who does the work knows, or ought to known that the property does not belong to him.  But it is very different when he honestly believes himself to be the owner of the property and does the work in that belief. …
Here we have an innocent purchaser who bought the car in good faith and without any notice of any defect in the title to it.  He did work on it to the value of £226.  The law is hard enough on him when it makes him give up the car itself.  It would be most unjust if the company could not only take the car from him, but also the value of the improvements he has done to it - without paying for them.  There is a principle at hand to meet the case.  It derives from the law of restitution.  The plaintiffs should not be allowed unjustly to enrich themselves at his expense. The court will order the plaintiffs, if they recover the car, to recompense the innocent purchaser for the work he has done on it.”
43.	When Mr Harper carried out the work on the Jaguar he was acting in his own self-interest, with a view to making a profit for himself when he sold the car.  Despite that fact, he had a restitutionary claim because he so acted under a mistake.  The mistake in question was not one induced by the true owner of the car.  I therefore disagree with the judge when he said that a mistake would only be relevant if it was one which the Bank encouraged Explora to make, or in respect of which the Bank knowingly stood by.  
44.	Mr McMeel’s three part test for the incidental benefit rule (which I have set out above) would not have deprived Mr Harper of his remedy on the facts of Greenwood because, he submits, in Greenwood the benefit conferred on the owner was “identical” to Mr Harper’s principal intended consequence.  On one level, that is plainly not the case.  Mr Harper did not intend the consequence that the owner should have the benefit of the repairs at all.  What Mr McMeel means, I think, is that the whole of the value of the work done on the car transferred to the owner.  But if it is unjust that the owner should benefit from the whole of the work done, I do not see why it is not also unjust if he should benefit from part of it.  I suspect Mr McMeel’s “identical” requirement is born more from a desire to distinguish Greenwood than from principle.
45.	If a claimant confers a benefit on a defendant in circumstances where he is acting in his own self interest, but labouring under a mistake so that he is actually conferring a benefit on someone else, I do not see why a court should deny a remedy simply on the ground that the benefit is not identical to that which the claimant intended to confer on himself.  Everything depends on whether the other ingredients of a cause of action in restitution are present. For my part I would resist the invitations of the parties on this appeal to formulate a general “incidental benefits” exception in the law of restitution.  There is in my judgment no reason to think that the existing conceptual structure explained in BFC is inadequate.  What is certainly true is that any such rule is too unclear both as to its formulation and its conceptual basis to form a secure foundation on which to strike out this action.  For my part, therefore, I would not have dismissed the action for the reasons given by the judge.
Respondent’s Notice
46.	By its respondent’s notice the Bank seeks to argue that the judge would have been justified in dismissing the claim because TFL had no real prospect of establishing that (a) the Bank has been benefited or enriched (b) any enrichment was at Explora’s expense (c) any enrichment was unjust in the required sense (d) the Bank was not entitled to a specific defence.  
Has the Bank been enriched?
47.	As Mr McMeel for the Bank has pointed out, the analysis of TFL’s claim is rendered more difficult by the failure to identify with precision the benefit which is said to have been conferred on the Bank.  This has been variously described as the expenditure of Explora’s legal costs, the work done to obtain the Court of Appeal judgment and to realise the debt for the Bank, the benefit of the Court of Appeal’s judgment, the commissions (or book debts) themselves and improving the right to the commissions (or book debts).  In his submissions before us, Mr Christopher Harris for TFL did not shrink from the criticisms of the way in which TFL’s case had been pleaded and advanced in his skeleton argument.  In his oral argument he focused on the benefit conferred on the Bank by the removal of obstacles which Hesco could place in the way of the Bank’s recovery of the book debts.  Many of the arguments run by Hesco in answer to the Explora claim were now precluded by issue estoppel. This represented a saving in the costs which the Bank would have to expend in recovering the debts, because all those points would have been run by Hesco had the Court of Appeal judgment not been “obtained” by Explora.
48.	Mr McMeel’s first argument on benefit is that the Bank did not benefit at all from the expenditure of costs.  TTF was always the owner of the book debts: Explora did not confer that benefit on TTF or the Bank.  On that argument he is undoubtedly right.  However, in the way that the argument is now put, it is not the book debts which are said to be the benefit.
49.	Considering the matter in that way, Mr McMeel accepts that it is arguable that some issues which were raised by Hesco and determined against Hesco in the Explora v Hesco claim would have been raised by Hesco if TTF had brought its own action for the book debts against Hesco.  However, he submits that TTF would have won on those issues and recovered its costs of doing so.  There is accordingly no saving of expense to the Bank.
50.	I am not able to accept that submission on a summary judgment application such as this. I regard it as commercially unrealistic to suppose that TTF did not benefit from the Court of Appeal judgment.  It is true that it could have pursued the litigation itself, but TTF would not have been indemnified as to its costs.  The fact that Hesco was bound by the Court of Appeal judgment meant, as TFL alleges in its particulars of claim, that the receivers could pursue a much simpler, less costly debt claim.  Such a claim would have led to a consequent reduction in irrecoverable costs.  Further, as Mr Harris points out in his written submissions, in addition to legal costs, in pursuing any claim the receivers would also be charging for their services.  I do not think that Explora’s claim to have conferred a benefit on TTF and the Bank can be dismissed as having no genuine chance of success.   It is essentially a question of fact which would have to be determined in the light of the evidence at a trial.
Was the enrichment of the Bank at Explora’s expense?
51.	As is pointed out in Goff & Jones at 6-01, the term "at the claimant's expense": 
"signifies that the claimant must have suffered a loss that was sufficiently closely linked to the defendant's gain for the law to hold that there was a transfer of value between the parties. This rule reflects the principle that the law of unjust enrichment is not concerned with the disgorgement of gains made by defendants, nor with the compensation of losses sustained by claimants, but with the reversal of transfers of value between claimants and defendants."
52.	The general rule in restitution is that only the direct recipient of the benefit is entitled to recover.  In Kleinwort Benson v Birmingham City Council [1997] QB 380 the Court of Appeal adopted a relatively strict approach to the requirement. Morritt LJ said at 400F that the words "at the expense of the plaintiff" pointed to the requirement that the claimant be the "immediate source". Evans LJ said at 393A that it had to be interpreted by reference to "the payer/payee relationship alone". Saville LJ said at 395A that the expression was a convenient way of describing the need for the payer to show that his money was used to pay the payee.
53.	By contrast in Filby v Mortgage Express [2004] EWCA Civ 759, May LJ said this at [62]:
“The enrichment will be at the expense of the claimant if in reality it was the claimant's money which effected the improvement.”
54.	The benefit conferred on the Bank, whatever it consists of, cannot in my judgment be described as having been directly conferred on the Bank by Explora.  The direct recipient of the money expended by Explora in costs was Explora’s legal advisers.  The direct recipient of the benefit of the Court of Appeal’s judgment was TTF.  Does TFL have a realistic prospect of showing, nevertheless, that the benefit conferred on the Bank was at the expense of Explora?  
55.	There is useful guidance to be found on the question of whether an indirect benefit can properly be treated as being at the claimant’s expense in the decision of Henderson J Investment Trust Companies (in liquidation) v HMRC [2012] EWHC 458 (Ch). The claimant investment trust companies employed managers to whom they paid fees which were subject to VAT. After the VAT had been paid, a decision of the Court of Justice of the European Union held that, contrary to what had been previously believed, the services in question were exempt. The claimants sought repayment of the sums which they had paid in the belief they were lawfully charged. One of the issues Henderson J addressed was whether, assuming HMRC was enriched, that enrichment was at the expense of the investment trusts. The payments to HMRC were not direct. 
56.	Having considered the divergent opinions adopted by academic writers and the decisions of the Court of Appeal in Kleinwort Benson v Birmingham City Council and Filby v Mortgage Express to which I have already referred, at [67] to [68] Henderson J concluded: 
"I must now draw the threads together, and state my conclusions on this difficult question. In the first place, I agree with Mr Rabinowitz that there can be no room for a bright line requirement which would automatically rule out all restitutionary claims against indirect recipients. Indeed, Mr Swift accepted as much in his closing submissions. In my judgment the infinite variety of possible factual circumstances is such that an absolute rule of this nature would be unsustainable. Secondly, however, the limited guidance to be found in the English authorities, and above all the clear statements by all three members of the Court of Appeal in Kleinwort Benson Ltd v Birmingham City Council, suggest to me that it is preferable to think in terms of a general requirement of direct enrichment, to which there are limited exceptions, rather than to adopt Professor Birks' view that the rule and the exceptions should in effect swap places (see "At the expense of the claimant": direct and indirect enrichment in English law, loc.cit., at page 494). In my judgment the obiter dicta of May LJ in Filby, and the line of subrogation cases relied on by Professor Birks, provide too flimsy a foundation for such a reformulation, whatever its theoretical attractions may be, quite apart from the difficulty in framing the general rule in acceptable terms if it is not confined to direct recipients. 
The real question, therefore, is whether claims of the present type should be treated as exceptions to the general rule. So far as I am aware, no exhaustive list of criteria for the recognition of exceptions has yet been put forward by proponents of the general rule, and I think it is safe to assume that the usual preference of English law for development in a pragmatic and step by step fashion will prevail. Nevertheless, in the search for principle a number of relevant considerations have been identified, including (in no particular order): 
a) the need for a close causal connection between the payment by the claimant and the enrichment of the indirect recipient; 
b) the need to avoid any risk of double recovery, often coupled with a suggested requirement that the claimant should first be required to exhaust his remedies against the direct recipient;
c) the need to avoid any conflict with contracts between the parties, and in particular to prevent "leapfrogging" over an immediate contractual counterparty in a way which would undermine the contract; and
d) the need to confine the remedy to disgorgement of undue enrichment, and not to allow it to encroach into the territory of compensation or damages." 
57.	I agree with Henderson J that these are relevant considerations in deciding the question of whether an indirect benefit was conferred at the claimant’s expense. But the various factors to which he refers are not, and were not I think intended to be, rigid principles.  Far less can it be said that if one or more of the factors can be said to be adverse to the claim, the claim is necessarily doomed to failure.
58.	Nevertheless, basing himself on this passage in Investment Trust Companies, Mr McMeel submitted that each of Henderson J’s considerations militates against the present claim.  
59.	Firstly he submits that TFL will not be able to establish a causal connection between their expenditure and a benefit to the Bank, because of the time delay between the judgment of the Court of Appeal and the settlement of the claim against Hesco (July 2005 to February 2008).  
60.	Next, he submitted that Explora has not exhausted its remedies against the Bank.  No application for costs against the receivers was made at the conclusion of the proceedings in the Court of Appeal.  The Court of Appeal made a detailed costs order, some time after its judgment had been handed down.  Explora had plenty of time to consider whether it wished to make any such application.  The court enjoys a wide discretion as to costs and could have made such an order.  Alternatively it could have directed that any issue as to Explora’s costs could have been dealt with in the Commercial Court.   The present action represents a collateral attack on the order made by the Court of Appeal, to which the receivers of TTF were party.
61.	Moreover, as was pointed out in argument, it would have been consistent with the case Explora now wishes to advance based on mutual mistake for Explora to have sought rectification of the CSA agreement and claim the benefit of the accrued commissions for itself.  It had not invoked this remedy either.
62.	Mr McMeel also submitted that the claim now made is in conflict with the rights of the Bank as set out in the CSA agreement. The CSA agreement provided for Explora to act as the Bank’s agent in collecting the book debts and to be remunerated by a percentage commission.  No agreement was made for the Bank to indemnify Explora for their legal costs.  If Explora had acted in accordance with the CSA agreement and collected the book debts on behalf of the Bank, as its agent, it would have been restricted to a claim for a percentage commission.  It should not be entitled to act in conflict with the CSA agreement, claim the book debts for itself, and, when it fails to recover, seek an indemnity from the Bank for doing so. 
63.	Mr Harris took us to the relevant clause of the CSA agreement and pointed to the fact that the obligations of Explora were relatively slight in return for a commission of 30% on such book debts as they collected.  Explora was to chase payment of the book debts by telephone and by sending fortnightly reminders.  What Explora had in fact done in bringing the Explora v Hesco proceedings in the mistaken belief that it was acting in its own interests, went much further.  He also submitted that it is unrealistic to suppose that TTF would have been able to pay any costs at that stage.  
64.	The Bank’s arguments on this limb of their respondent’s notice are undoubtedly powerful ones.  However, in common with the judge, I would not feel able to dismiss TFL’s claim summarily on the basis of them.  Firstly, I do not feel able to say that there is an insufficient causal connection based simply on the passage of time.  Litigation inherently takes time, and it is not surprising that it took the receivers some time to achieve settlement with Hesco.  Secondly, I am not persuaded that the existence of either of the alternative remedies (seeking costs from the Court of Appeal or rectification) is really in point.  Although courts are able to make other orders, the general rule is that costs follow the event.  To suggest that Explora’s counsel could have risen to his or her feet in the Court of Appeal and asked for a costs order in favour of Explora because, by losing, it had conferred a benefit on TTF is, in my judgment, unrealistic.  But that is not because TTF had not benefited at Explora’s expense.  It is because courts do not normally award parties the costs of issues on which they have lost against counterparties who have taken no part in the proceedings.  To my mind, the litigation costs regime has little or nothing to do with the claim which Explora now wishes to bring.  For the same reason the action which it now brings is, at least arguably, not a collateral attack on the order of the Court of Appeal.  Equally, although it is true to say that Explora could, consistently with its allegations in these proceedings, have sought rectification of the contract, that fact alone does not defeat the unjust enrichment claim based on the benefit of the Court of Appeal judgment.  It is obviously fatal to any claim to the book debts, but that, as I have said, is doomed to failure anyway.
65.	I do not think that the point made on the CSA agreement is fatal either.  I accept that there is a principle that the court will not normally order the recovery of benefits conferred pursuant to a contractual obligation, because to do so would be to act in conflict with the agreed contractual background.  But here, Explora allege that they went further than they were obliged to do under the terms of the CSA agreement.  I do not think the contractual term on which Mr McMeel relies defeats the claim. 
Was the enrichment unjust?
66.	The principal point taken by the Bank under this heading was that Explora must be regarded as having taken the risk that it would lose.  Explora was acting in its own self interest.  In the absence of any encouragement by the Bank the enrichment cannot be regarded as unjust.  To hold the contrary would throw on the Bank the burden of legal costs for services over which it had no control.
67.	In my judgment this submission was rightly rejected by the judge as well.  The summary judgment application is proceeding on the basis that both Explora and the Bank thought that the effect of the contract was to assign the commissions.  Whilst on full investigation it may turn out that Explora knew or ought to have known of the risk, we cannot work on that assumption.  Neither self-interest nor the absence of encouragement provides an answer: see Greenwood v Bennett.  The fact that the Bank had no control over the costs is not determinative either. 
68.	On the assumed facts it is possible for TFL to argue “with some degree of conviction” that Explora conferred a real benefit on the Bank, that the benefit was incurred at Explora’s expense and that it would be unjust for the Bank to retain it.  
Defences
69.	Under this head Mr McMeel listed the points about conflict with the CSA agreement and the failure to seek costs in the Court of Appeal.  I have already dealt with these issues under other heads.  Nothing is added by considering them separately here. I should indicate that the Bank did not advance any argument based on a defence of change of position.
Conclusion
70.	It follows that neither the main point on the appeal, or any of the points argued on the respondent’s notice provides, in my judgment, a basis for granting summary judgment.    For my part, I would allow the appeal.  
Sir Stanley Burnton:
71.	I am grateful to Lord Justice Floyd for setting out the uncontroversial and the assumed facts of this case. I regret that I do not agree that this appeal should be allowed. I am clear that the claim in unjust enrichment cannot succeed. My reasons are not those of His Honour Judge Pelling QC. I have not approached the appeal by seeking to apply general principles of unjust enrichment or by applying any definition of incidental benefit. I have rather considered the particular facts of this case.
72.	It is significant that Mr Harris was unable to identify quite what is the unjust enrichment that the TFL claims. Is it the amount of the costs Explora incurred in the proceedings that resulted in the judgment of the Court of Appeal that declared the accrued commissions to be book debts that had been retained by the receivers under the CSA agreement? Is it to be measured by the sum received by the receivers or the Bank from Hesco? I understood Mr Harris to submit that the claim was for a sum in between these figures. I ask rhetorically: by what standard, and on what basis, is the trial judge to arrive at a figure to be paid by the Bank to TFL? No such standard, and no such basis, has been identified. This is not a merely formal difficulty for TFL. It is a symptom of the lack of a justiciable cause of action.
73.	I first consider the claim in so far as it seeks reimbursement, or a sum, on account of, or reflecting, the costs incurred by Explora in the litigation against Hesco. In my judgment this part of the claim, as the Bank’s skeleton argument on this appeal contended, seeks to circumvent the costs jurisdiction of the Court. The time for making any such claim was when the Court of Appeal handed down its judgment on the construction of the CSA agreement. The tribunal before which such claim could and should have been made was the Court of Appeal that had heard the appeal and which gave that judgment. We do not know whether Explora made an application for costs. I do not think it matters. It is not for the Court now to make an order that would have the effect of an order that could have been made in the proceedings in which the costs were incurred. Moreover, it seems to me to be obvious that if any application for costs had been made by Explora against the receivers, it would have been bound to fail. The receivers had not taken a position adverse to Explora. The receivers may be regarded as having succeeded on the issue of the right to the accrued commissions. No basis has been suggested for rendering them liable for any part of Explora’s costs. Explora might have asked for costs as between it and Hesco to be awarded on an issue basis, since Explora had succeeded on every issue as against Hesco other than the right to the accrued commissions. It did not do so, or its application was rejected; in any event, the tribunal to consider such an order was that Court of Appeal. It follows that there is no injustice in Explora bearing its costs of its unsuccessful claim against Hesco. 
74.	I think it is also worth bearing in mind that if the receivers had played an active part in the previous proceedings, they would have succeeded and recovered most of their costs against Hesco and Explora. So the actual saving of the receivers’ costs to which TFL point would not approach the costs incurred by Explora. 
75.	The second aspect of the claim relates to the sum received by the receivers and subsequently by the Bank from Hesco. It was paid under the CSA agreement, as construed by the Court of Appeal. The receivers’ right to this sum was conferred on them by the agreement into which Explora entered. There is a well-established remedy for correcting a provision that has been included in a contract by common mistake, namely rectification. That remedy has not been sought and is not sought. Indeed, the evidence is that Explora made a conscious decision not to seek it. In the absence of rectification, the parties to that Agreement must be taken to have intended that accrued commissions were to be included in the retained assets. In the absence of rectification, there is no legal basis to deprive the receivers, or the Bank, of that to which they were entitled under the CSA agreement, or any part of it. In this connection it must be borne in mind that the Court of Appeal did not confer any right on the receivers. The receivers were not enriched by the judgment of the Court of Appeal. A judgment of the Court on the construction of a contract is declaratory, simply making clear what was agreed by the parties to it. There is no injustice in the receivers and the Bank retaining that to which the parties to the CSA agreement provided they should have.
76.	I add that if, contrary to my view, the receivers must be taken to have obtained a benefit from the judgment of the Court of Appeal, I see real difficulty in assessing any value to it. One lawyer may have advised that the effect of the exclusion of book debts was one of difficulty; another might have concluded that it was obvious. We are looking at perceptions, which are necessarily subjective.
77.	In my judgment, for the reasons I have endeavoured to give, TFL cannot succeed in establishing a claim for unjust enrichment. It is bound to fail. I have assumed that it will establish all the facts that it contends give rise to its claim. There is no point in a trial of its claim. I would therefore dismiss this appeal.
Lord Justice Beatson :
78.	I am grateful to Lord Justice Floyd for his comprehensive description of the factual assumptions upon which this appeal must proceed and the issues in it. I agree with his conclusion that it is not possible summarily to dismiss TFL's claim, and with his reasoning. Since we are divided, and in tribute to the excellent submissions of Mr McMeel, I would like to add a short judgment of my own.
79.	It is understandable that the factual circumstances of this case would lead someone coming to them (including many familiar with the development of the modern law of restitution) to believe that a claimant in the position of TFL has a high and possibly insurmountable hurdle. 
80.	There are a number of reasons for scepticism about a claim such as that brought by TFL. The first is that it is seeking restitution for services and the familiar difficulties of identifying the benefit (reflected in the different ways TFL has sought to identify it at different stages of these proceedings) arise: see Floyd LJ's judgment at [47] and Sir Stanley Burnton's at [72]. Secondly, TFL rendered the services when acting (so it believed) in its own interest. 
81.	The third reason for scepticism is that the services rendered consisted of conducting litigation, an activity which is inherently risky, and about which (and around which) the interests of finality are particularly strong. So, for example, a settlement of a claim which is entirely unfounded and thus worthless is binding save where the claimant who has benefitted from the settlement had no honest belief in his claim: Callisher v. Bischoffsheim (1870) LR 5 QB 449. In that context, the force of the policy favouring finality had a deleterious effect on the development of the law of restitution because cases that are in fact explicable as instances of submission to a claim or a compromise were, until the decision in “The Siboen and The Sibotre” [1976] 1 Lloyd's Rep 293 at 336, taken to preclude the setting aside of a contract on the ground of non-physical coercion or duress. 
82.	Mr McMeel observed that in Explora’s litigation against Hesco it put arguments to the Court which were adverse to the interests of TTF’s receivers and the Bank. As a result of this, he argued that TFL is not entitled to restitution from TTF (and thus from the Bank). It pursued its claim against Hesco for itself and maintained during the litigation that the benefit did not belong to TTF’s receivers and, after it did not succeed, it should not be entitled to turn on the receivers, and, through them, the Bank.  His characterisation of TFL's position was that it in effect wanted both to have its cake and to eat it, and that its current position is fundamentally inconsistent with the position Explora had taken in the litigation. This is essentially to maintain that Explora was a risk-taker and that, having taken the risk and not succeeded, is not entitled to pass the cost onto TTF’s receivers by now characterising what it did for itself as a service rendered for the benefit of the receivers and through them the Bank.
83.	As far as "benefit" is concerned, TFL’s position as to the nature of the benefit conferred crystallised during the hearing. Mr Harris focused on the costs the Bank saved in recovering the accrued commissions as a result of the expenditure incurred by Explora in the proceedings against Hesco. Those proceedings resulted in the judgment of the Court of Appeal that declared the commissions to be book debts that had been retained by the receivers under the CSA agreement, and thus accrued to the Bank. I agree with Floyd LJ that, in the abstract and without findings of fact, it is commercially unrealistic to proceed on the basis that TTF did not benefit from the Court of Appeal judgment. The question of the extent of the benefit is more problematic. It does not follow that because the litigation costs incurred by TFL amounted to some £550,000, that is also the amount by which TTF/the receivers and thus the Bank benefitted.
84.	The question is then whether there is a principle barring restitution in respect of benefit of the sort that has been conferred. As my Lord, Floyd LJ, also stated (see [32] - [37]), the discussions by scholars of a suggested principle under which restitution of so-called "incidental benefits" are so barred, recognise that the scenarios relied on are "generally" ones in which the question is whether a benefit is to be regarded as "at the expense of" the claimant or one of the factors negativing voluntariness or qualifying consent is present. 
85.	It is also to be observed that the three part test advanced by Mr McMeel (see [22]) may prove too much and exclude many cases in which restitution has been ordered. One of these is the classic case of a payment by A to B made in A’s mistaken belief that he owed B the money where, at least since Kelly v Solari (1841) 9 M & W 54, A has (subject to defences) been entitled to recover the money. From A’s point of view it can legitimately be said that the principal intended consequence of the payment is the discharge of A’s obligation to B. Because of the mistake, however, the benefit to B is not identical to that intended consequence. It is the receipt by B of the money. 
86.	Given the position in the scholarly commentaries, and the absence of decisions which explicitly proceed on the basis of a principle barring "incidental benefits", or any clear (let alone agreed) formulation of what it is which is to be prevented, I do not consider that it is appropriate to give summary judgment on the basis of a general principle barring restitution in respect of benefits conferred “incidentally”. To do so would, in particular, be to discount the possible alternative explanations for the scenarios which have been said to be examples of its operation. 
87.	Is there anything else on the assumed facts of this case which would justify summary judgment and the deputy judge's order? This involves consideration of a number of other questions. The first and most important is whether Explora must, on the assumed facts, be regarded as having voluntarily conferred the benefit. It will be so regarded unless one of the factors negativing voluntariness (such as mistake or compulsion), or qualifying consent to a transfer (notably failure of consideration) are present. The question of risk, and the significance (if any) of the fact that the services in respect of which restitution is now sought were rendered by Explora in the course of litigation for its own benefit are relevant to this question. 
88.	As to Explora acting in its own interest and taking a risk which it should not be able to reallocate to TTF, it is important for present purposes that it has to be assumed that Explora was mistaken. I agree with Floyd LJ that the deputy judge adopted an unduly narrow formulation of the type of mistake required where restitution is claimed on the basis that a benefit has been conferred by mistake. It is quite clear that, for the purposes of the recovery of money paid, a very broad range of mistakes will suffice, even those caused by the payer's negligence (Barclays Bank Ltd v WJ Simms [1980] QB 677, 686-7). In the case of mistakenly conferred services, there may be a difference, but any difference stems principally from the fact that the rendering of a service is not always or even generally incontrovertibly beneficial. Greenwood v Bennett [1973] 1 QB 195 shows that, even in the case of services, there is no need for the mistake to have been induced by the recipient or for the recipient to stand by when the person rendering the services does so. In any event, on the facts of the present case it is arguable that TTF’s receivers did so induce the mistake (by entering into the assignment) and then stood by when Explora pursued its litigation against Hesco, and that the Bank is, as the holder of the charge over TTF's assets, in no better position than TTF’s receivers.
89.	Four other questions arise. The first is whether the enrichment was at Explora's (and thus at the TFL's) expense. The second is whether Explora was in fact a risk-taker, and if it was, what risk it was taking, and whether doing so precluded a restitutionary claim by it because such a claim would re-allocate a risk it chose to bear. Like Floyd LJ, I consider the Bank has powerful arguments on these questions, but agree with him and the deputy judge that these are questions which are intensely fact-specific and thus not suitable for summary determination. I also agree with my Lord that these proceedings are not fatally flawed at this stage either because they constitute a collateral attack on the costs order made by the Court of Appeal, to which TTF’s receivers were party, or because Explora/TFL should have sought rectification of the CSA agreement.