An analysis of the High Court decision in Redland City Council v Kozik [2024] HCA 7

In 2022, I authored an article in Issue 88 of Hearsay about the Supreme Court of Queensland decision in Kozik & Ors v Redland City Council [2021] QSC 233 (see The Fruits of an Unlawful Demand). That decision concerned the entitlement of plaintiff ratepayers to restitution of tax paid pursuant to an unlawful demand by a local government. Since that article was published, Bradley J’s decision has been the subject of appeals to the Queensland Court of Appeal and, more recently, the High Court.

In my previous article, I emphasised Bradley J’s finding that the plaintiffs had a statutory entitlement to restitution. That finding removed the need to consider any common law action for unjust enrichment.  For the sake of discussion, I then explored the counterfactual: identifying difficulties that may confront plaintiffs in recovering unlawfully exacted tax under the common law where legislation does not require repayment.

Since my article, that counterfactual became reality in this case. Contrary to Bradley J’s findings, the High Court in Redland City Council v Kozik [2024] HCA 7 held that no statutory entitlement to restitution arose. It was therefore necessary for the Court to confront the unjust enrichment issue – an issue that split the Court 3/2. The decision is a fascinating one and has real implications for the law of restitution in Australia.

BACKGROUND

The background to this matter is summarised in my previous article on this case. In short, the appellant, Redland City Council, had passed resolutions to levy special charges on an area of land, including land owned by the respondents, to fund services relating to nearby water reserves. The Council demanded, and was paid, the special charges by the respondents and other landowners.

It was later discovered that each of the Council’s resolutions to levy the special charges was unlawful. This was so because, contrary to requirements in statute, the resolutions did not properly identify an ‘overall plan’ for the services to which the special charges applied.

The Council refunded the unspent portion of the special charges but refused to refund the remainder on the basis that it had been spent on services benefiting those who had paid. The respondents, who were plaintiffs in a representative action on behalf of other affected landowners, sought the repayment of the remainder of the funds.

At first instance, Bradley J determined that the rate notices by which the Council levied the special charges were not invalid by virtue of regulations passed pursuant to the Local Government Act 2009 (Qld) – referred to as ‘validating regulations’. Because the validity of the rate notices was preserved, His Honour found the respondents had not paid under a mistake of law so as to give rise to a common law claim for restitution. Nevertheless, under the same validating regulations, the respondents were entitled to recover the remainder of the funds as a debt.

On appeal, a majority in the Court of Appeal held that the validating regulations did not apply to the special charges and that, consequently, the rate notices were invalid and payments made by the taxpayers were not recoverable in debt. It was determined that, instead, the payments were recoverable as restitution on the ground of a mistake of law.

The matter ultimately split the High Court. A majority (Gordon, Edelman and Steward JJ) dismissed the Council’s further appeal; largely affirming the Court of Appeal’s reasoning. The minority (Gageler CJ and Jagot J) held that a prima facie entitlement of the landowners to restitution was displaced by a defence not previously recognised by the High Court. The majority and minority decisions are explored below.

OPERATION OF VALIDATING REGULATIONS

Contrary to the findings of the primary judge, all justices of the High Court concluded that the validating regulations were not engaged. In so deciding, the Court distinguished between, firstly, errors at the stage of resolving to levy the special charges, and, secondly, errors at the stage of actually levying the tax. The validating regulations only preserved rate notices in the event of certain kinds of error at the second stage. Application of the validating regulations was said to be premised upon the existence of a valid resolution.

Here, none of the resolutions were valid and, consequently, the Council lacked power to levy the charges. As explained by the majority, ‘there was nothing to which the rate notices issued by the Council to the respondents could attach…’.[1]

RESTITUTION OF UNJUST ENRICHMENT

The absence of any statutory right to restitution brought into focus the respondents’ common law action for restitution of unjust enrichment. The High Court has previously described the term ‘unjust enrichment’ as referring to categories of case where the law imposes upon a defendant an obligation to make restitution for a payment, or other benefit, derived at the expense of a plaintiff.[2]

All actions for restitution for unjust enrichment involve a two‑stage inquiry. At the first stage, a plaintiff must demonstrate a prima facie entitlement to restitution. To do so, the plaintiff must establish that a recognised ‘qualifying or vitiating factor’ operated on the making of the payment. Factors capable of founding a taxpayer’s entitlement to recover tax paid in an action for restitution include ‘mistake of law’. At the second stage, it is open for a defendant to displace the plaintiff’s prima facie entitlement by pointing to ‘circumstances which the law recognizes would make an order for restitution unjust’.[3]

In this case, the first stage of the inquiry was uncontentious. The landowners were said to have demonstrated a prima facie entitlement to restitution. They had paid the special charges in the mistaken belief that they were under a legal obligation to do so and, consequently, the ‘mistake of law’ factor was engaged. It was the second stage of the inquiry that divided the Court.

‘Good consideration’ defence

As a defence to the restitution claim, the Council argued that the rate payments were made for ‘good consideration’ – namely, for the benefit conferred upon the taxpayers by the work the subject of the special charges. Both the majority and minority rejected that argument. The majority did so on three bases.

First, the majority said that restitution of the special charges would not ‘cause the basis of the Council’s performance of the relevant works to fail’. The Council was obliged by statute to perform the relevant works. The services were provided on that basis and not in exchange for payment of the special charges.

Second, the majority held the relevant works did not ‘benefit’ the landowners in the sense necessary to satisfy a defence of good consideration. Generally, A will obtain a benefit in that sense where B performs a non-gratuitous service that A had requested, or for which A freely accepted a liability to pay. The majority emphasised that, in this case, the landowners had not requested, nor freely accepted, the Council’s services. They were not in a position to reject performance of the works.

Third, the application of a ‘good consideration’ defence would, it was found, stultify the operation of the relevant legislation. The purpose of conditioning the power to impose special charges on the preparation of an overall plan was said to be one of community protection; ensuring local governments take care before incurring substantial costs that ‘will ultimately be borne by a section of the community’. The majority found that purpose would be undermined if, despite the lack of an overall plan, restitution to the taxpayers was prevented on the basis of ‘good consideration’.

‘Recipient not unjustly enriched’ defence

The central controversy arising in the majority and minority judgments was the application of a defence termed ‘recipient not unjustly enriched’ (‘RNUE defence’) – a concept recognised in the United States, but not previously by the High Court. Under the claimed RNUE defence, a prima facie entitlement to restitution of a benefit may be defeated where a defendant can show the benefit conferred ‘did not unjustly enrich the recipient when the challenged transaction is viewed in the context of the parties’ further obligations to each other’.[4] The RNUE defence is said to have a basis in equity; requiring consideration of the justice of the impugned transaction in light of ‘the larger transactional circumstances’.[5]

The majority decided that no separate RNUE defence should be recognised in Australia. Their Honours found that the RNUE defence uses the concept of unjust enrichment as a premise of direct application – that is, it contemplates an assessment of the ‘perceived injustice’ of the transaction in question. This is in circumstances where unjust enrichment is, properly understood, not a concept capable of direct application and is, instead, ‘a conclusion of a process of reasoning’.[6]

The majority rejected the equitable basis for the RNUE defence. It was said that, though the foundations of the law of unjust enrichment lie in the principles of natural justice and equity, those concepts are not capable of direct application in the context of restitutionary claims and defences.  In view of the majority, it is not appropriate to determine whether an enrichment is unjust ‘by reference to some subjective evaluation of what is fair or unconscionable.’ Instead, restitution involves ‘determination, by the ordinary processes of legal reasoning’ of whether an obligation arises to make restitution.[7]

The minority disagreed; recognising the RNUE defence and finding that it defeated the landowners’ prima facie entitlement to restitution. The minority found that the Council’s retention of the payments did not result in the Council being unjustly enriched ‘when viewed in the context of the statutory obligations and entitlements of the Council and of the Landowners’.[8]

The minority outlined a number of circumstances demonstrating that the Council’s retention of the moneys would not be unjust.[9] First, it emphasised that the Council was statutorily obliged to undertake the works. Second, the works resulted in ‘special benefit’ to the land of the Landowners (as that term was defined in the relevant legislation), sufficient to entitle the Council to resolve to levy special charges for the works. Third, invalidity of the resolutions did not arise from a lack of statutory power to levy the special charges in fact levied but from an error in the process by which that power was purportedly exercised. Fourth, the Council in fact used the moneys paid to it by the Landowners as special charges exclusively for the purpose of funding the works, refunding the surplus to the Landowners. Fifth, the Council acted in good faith; honestly believing that it had complied with the required processes.

Seemingly in response to the majority’s criticisms, the minority asserted that the RNUE defence involves no ‘direct application’ of the concept of unjust enrichment. Rather, the defence was said to indicate circumstances which can operate to deny an ‘occasion of unjust enrichment supporting claims for restitutionary relief’.[10] The minority argued that the range of circumstances establishing a defence to a prima facie entitlement to restitution should not be narrowly confined; particularly in light of its ‘equitable underpinning[s]’ of the common law action.[11]

In answer to the majority’s concerns about stultification of the statutory regime, the minority observed that common law liability in restitution, where it arises in the event of breach, is a collateral consequence of statutory invalidity. The liability is exposure only to a prima facie entitlement to restitutionary relief. Accordingly, there was said to be no ‘stultification’ in the Court staying its hand in the face of the RNUE defence.[12]

WOOLWICH

In my article about the first instance decision, I explained that English courts have recognised that claims for restitution of unjust enrichment can be grounded solely upon the unlawful act of a public authority – that is, without the need to demonstrate a right to restitution on any other ground. I discussed the decision in Woolwich Equitable Building Society v Inland Revenue Commissioners [13] where the House of Lords held that money paid by a citizen to a public authority in the form of taxes or other levies paid pursuant to an ultra vires demand by the authorities was recoverable as of right.

Whether the Woolwich principle should be imported into the common law of Australia was described by the minority in Kozik as ‘a large question’; involving consideration of existing High Court authority and, interestingly, the scope and content of the prescription in s 64 of the Judiciary Act 1903 (Cth) that ‘[i]n any suit to which the Commonwealth or a State is a party, the rights of parties shall as nearly as possible be the same … as in a suit between subject and subject’.[14] 

However large the question, the Court ultimately refused to answer it; both the majority and minority finding it not determinative of the issues on appeal. The minority expressed a view that, regardless of its application in Australia, entitlement of a taxpayer to recovery on the Woolwich principle was prima facie and subject to displacement by defences. This was so despite references in English caselaw to ‘high principles of public policy’ tending against the recognition of defences to the principle.[15]

IMPLICATIONS

A number of principles can be distilled from the majority’s reasoning in Kozik. Most fundamentally, the decision makes clear that Australian law does not recognise a RNUE defence to a claim for restitution of unjust enrichment. The term ‘unjust enrichment’ is not a premise capable of direct application and concepts of justice or fairness are not themselves relevant to either stage of the unjust enrichment inquiry. That is, they are irrelevant to whether a prima facie entitlement to restitution has arisen, nor are they relevant to the question of whether that entitlement has been displaced.

The decision also confirms that the Woolwich principle is not yet recognised in Australian law. In this sense, restitutionary claims against governments are treated no differently from claims against private citizens. Aggrieved taxpayers must rely on orthodox restitutionary principles to recover tax the subject of unlawful demands.

However, as Kozik demonstrates, when those principles are applied to claims for restitution by citizens who have paid tax under a mistaken belief that government has complied with the law in demanding that tax, the prima facie entitlement to restitution that arises will often be very difficult to displace.

Finally, the decision is a reminder of how claims for restitution of unjust enrichment should be pleaded. As identified by the majority, such claims should not seek to directly invoke the concept of ‘unjust enrichment’. Doing so will render a pleading liable to be struck out as disclosing no cause of action. Instead, reference should be made to an established category of restitution (for example, mistake or duress). Similarly, practitioners should refrain from pleading in a defence ‘no unjust enrichment’ as a premise of direct application. Instead, reference should be made to a recognised defence to any prima facie entitlement to restitution.[16]

The High Court’s decision can be found here.

[1] Redland City Council v Kozik [2024] HCA 7, [176] (Gordon, Edelman and Steward JJ).

[2] Equuscorp Pty Ltd v Haxton (2012) 246 CLR 498, 516.

[3] Redland City Council v Kozik [2024] HCA 7, [73] (Gageler CJ and Jagot J) referring to David Securities Pty Ltd v Commonwealth Bank of Australia (1992) 175 CLR 353, 379.

[4] Redland City Council v Kozik [2024] HCA 7, [215] (Gordon, Edelman and Steward JJ).

[5] Redland City Council v Kozik [2024] HCA 7, [94] (Gageler CJ and Jagot J).

[6] Redland City Council v Kozik [2024] HCA 7, [217] – [219] (Gordon, Edelman and Steward JJ).

[7] Redland City Council v Kozik [2024] HCA 7, [226] (Gordon, Edelman and Steward JJ).

[8] Redland City Council v Kozik [2024] HCA 7, [131] (Gageler CJ and Jagot J).

[9] Redland City Council v Kozik [2024] HCA 7, [120] – [125] (Gageler CJ and Jagot J)

[10] Redland City Council v Kozik [2024] HCA 7, [97] (Gageler CJ and Jagot J)

[11] Redland City Council v Kozik [2024] HCA 7, [74] (Gageler CJ and Jagot J).

[12] Redland City Council v Kozik [2024] HCA 7, [130] (Gageler CJ and Jagot J).

[13] Woolwich Equitable Building Society v Inland Revenue Commissioners [1993] AC 70.

[14] Redland City Council v Kozik [2024] HCA 7, [78] (Gageler CJ and Jagot J).

[15] Redland City Council v Kozik [2024] HCA 7, [78] – [83] (Gageler CJ and Jagot J).

[16] Redland City Council v Kozik [2024] HCA 7, [217] (Gordon, Edelman and Steward JJ).

An analysis of the Supreme Court of Queensland ’s decision in Kozik & Ors v Redland City Council [2021] QSC 233, noting the decision has been appealed to the Queensland Court of Appeal. The Court of Appeal has reserved its decision.

PRELIMINARY

Where a public authority takes tax paid by a citizen pursuant to an unlawful demand, should the citizen be entitled to repayment of that tax? To answer that question, one must dive into the often-murky waters that lie between the invalid acts of government and the granting of monetary remedies to aggrieved individuals.

The rationale behind the affirmative argument is plain to see. It has been said that there exists ‘manifest injustice’ in allowing moneys unlawfully exacted from a person by a public authority to be retained.[1] It seems ‘strange’ to penalise the innocent taxpayer whose natural instinct is to trust the public authority, who pays tax at the compulsion of the authority’s coercive powers, and whose only fault is that it paid what the authority improperly said was due.[2] Why should the taxpayer bear the burden of the government’s mistake? And why should the government have the benefit of further funding as the fruit of its unlawful action?

On the other hand, it has been claimed (perhaps less convincingly) that to recognise a broad right of recovery for unlawful exactions of tax would be to ‘throw the finances of the country into utter confusion’ and would create ‘fiscal chaos’.[3]

In this country, funds paid in error to public entities have been described as ‘surprisingly difficult to recover’.[4] Courts in Australia and in other jurisdictions have encountered real difficulties in reconciling errors by public authorities with the restitutionary claims of private citizens. To address these concerns, parliaments in many jurisdictions have enacted regimes for the recovery of unlawfully exacted tax.

This kind of statutory regime was the subject of the recent Supreme Court of Queensland decision of Bradley J in Kozik & Ors v Redland City Council[5] (‘Kozik’). The purpose of this article is to analyse the decision in Kozik and its implications. Ultimately, it will be shown that the decision emphasises the importance of the legislature’s role in ensuring that citizens have a right of restitution in circumstances where public authorities make unlawful demands for tax.

KOZIK

The decision in Kozik concerned a representative action brought by the plaintiffs against Redland City Council (‘Council’) to recover payments of special charges.

Statutory framework

Council is a local government in the sense contemplated by the Local Government Act 2009 (Qld) (‘LG Act’) and, as a creature of statute, derives its powers from legislation. The LG Act vests powers in local governments to impose rates and charges on land.[6] While local governments are obliged to levy general rates,[7] they are conferred with a discretion to levy a special rate or charge.[8] The power to levy a special charge is to be exercised by a resolution of councillors.[9]

Whilst a resolution of a local government engages the statutory authorisation to exercise a taxation power, the giving of a rate notice to an owner of land engages the statutory mechanism to make the tax due and payable. If the owner of rateable land owes a local government for overdue rates and charges, the overdue rates and charges are deemed to be a charge on the land.[10]

Importantly, regulations contain what Bradley J referred to as ‘validating regulations’.[11] Where a rate notice includes special rates or charges that are levied on land to which the special rates or charges do not apply, the validating regulations operate to save the rate notice from invalidity, but concurrently oblige the local government to return those special rates or charges.

The effect of the validating regulations is to preserve a local government’s right to collect special charges levied by rates notices in circumstances where the resolutions to levy the special charges are themselves invalid.[12] Affected persons lose what might otherwise be a right to set aside the notice or to ask the court to declare it to be of no effect. But in place of that right, by the same validating regulations, an obligation is imposed on the local government to return the funds paid for the special charges that did not apply to their land.[13]

Factual background

Between June 2011 and July 2016, Council passed resolutions to levy special charges on land adjacent to particular water reserves, including land owned by the plaintiffs (‘the Resolutions’). These special charges were levied to fund capital and operational expenditure on services relating to the reserves.

Council issued rate notices to the owners of the relevant land, including the plaintiffs. The rate notices included the special charges contemplated by the Resolutions. The plaintiffs paid the amount noted on each of the rate notices they received, including the amount of the special charges.

However, it was later discovered that the Resolutions had been passed without compliance with statutory preconditions to the exercise of the authority to resolve to levy a special rate or charge.[14] Upon discovering its error, Council refunded a proportion of the special charges. When the plaintiffs sought to recover the balance of the special charges not refunded by Council, Council asserted that it was not obliged to return the ‘spent’ portion of the special charges on grounds that this amount was spent on services for the benefit of all the those who paid the special charges, including the plaintiffs.

Bradley J did not accept these arguments by Council. His Honour held that Council was liable to each of the landowners under a cause of action in debt for the balance of the special charges paid. Bradley J’s judgment hinged largely upon the operation of the validating regulations. His Honour found that each of the Resolutions were invalid and were therefore ‘incapable of ever having produced legal effects.’[15] Consequently, for the purposes of the validating regulations, the rates and charges specified in the Resolutions did not apply to the relevant land.

In default of returning the balance of the amounts paid for special charges by the group members ‘as soon as practicable’, the effect of the validating regulations (particularly the obligation to return the special rates or charges) was that Council was liable to each of those landowners under a cause of action in debt. As explained by Bradley J, the validating regulations saved the rate notices, but did not ‘validate or give effect to a purported resolution to levy the special rate or charge that is invalid and of no effect’.[16] The requirement in the validating regulations that that payment for the special charges be returned was unqualified.[17]

Additionally, Bradley J held that Council could not avoid or diminish its statutory obligation to return the amount of the special charges to each person who paid them, by a defence that the payers will be unjustly enriched by the return.[18]

DISCUSSION

In the author’s view, the judgment in Kozik is best characterised as an exercise in statutory construction. The outcome (i.e. liability of Council to the plaintiffs under a cause of action in debt) was a product of the taxation regime established under the LG Act framework. It was not a product of any general principle that, where a public authority takes tax paid by a citizen pursuant to an unlawful demand, the citizen is entitled to repayment of that tax.

The obligation to return the payments for the special charges to the landowners who paid them is an essential element of the regulatory scheme and could not be ‘cut down’ by resort to restitutionary principles.[19] It is therefore unsurprising that Bradley J did not consider it necessary to consider whether any unjust enrichment cause of action arose on the part of the plaintiffs. In this sense, the decision demonstrates that common law restitutionary considerations cannot purport to override a statutory regime for recovery that is intended to be exhaustive.[20] In the circumstances, the legislation at issue in Kozik was sufficient to provide a monetary remedy to persons affected by the unlawful exactions of special charges by Council.

But how important are statutory regimes for the recovery of unlawfully exacted tax? Would a right to be reimbursed have arisen in Kozik even in the absence of the validating regulations? As will be shown, in the absence of legislation of this kind, plaintiffs in Australia are confronted with some obstacles in recovering tax paid pursuant to unlawful demands.

English courts have recognised that a claim for unjust enrichment can be grounded solely upon the unlawful act of a public authority. In Woolwich Equitable Building Society v Inland Revenue Commissioners[21] (‘Woolwich’), the House of Lords held that money paid by a citizen to a public authority in the form of taxes or other levies paid pursuant to an ultra vires demand by the authorities was recoverable as of right.[22] There is no need to show a right to restitution on any other ground.

Curiously, no such principle has gained authoritative recognition in this country. Whilst the approach of the House of Lords in Woolwich has ‘been mentioned without criticism, and even approval, in a number of Australian cases’,[23] the High Court is yet to rule on its applicability.[24]

Consequently, in the absence of statutes providing a right of reimbursement like those the subject of Kozik, aggrieved taxpayers must rely on orthodox restitutionary principles to recover tax the subject of unlawful demands and, in particular, must satisfy the standard elements of unjust enrichment. [25] To succeed in a claim for unjust enrichment, a plaintiff must establish, amongst other things, that the enrichment of the defendant occurred by virtue of one or more recognised classes of ‘qualifying or vitiating’ factors (i.e.  mistake, duress, illegality or failure of consideration) by reason of which the enrichment of the defendant is treated by the law as unjust.[26]

It is conceivable that, had the validating regulations not applied to the special charges the subject of Kozik, the plaintiffs in Kozik could have asserted that the payment of the special charges was made under a mistaken belief of validly and, in that sense, gave rise to an obligation on the part of the public authority to make restitution. Additionally, plaintiffs could have sought to establish that they paid the special charges under duress, that is – a reasonable apprehension that Council would exercise extra-curial means of harming the plaintiff’s interests.  

However, the success of these arguments in such a hypothetical claim would be dependent on evidence of the plaintiffs’ intention for making the payments and not on the legality of Council’s actions. Arguably, these avenues to establish a right to restitution are more arduous from the perspective of a plaintiff. Ultimately, in this sense, the decision Kozik emphasises the importance of the legislature’s role in ensuring that citizens have a right of restitution in circumstances where public authorities make unlawful demands for tax.

[1] Test Claimants in the FII Group Litigation v Revenue and Customs Comrs (formerly Inland Revenue Comrs) [2012] 2 AC 337 at 372 per Lord Walker citing ‘Restitution: Mistakes of Law and Ultra Vires Public Authority Receipts and Payments’ (1994) (Law Com No 227).

[2] see Woolwich Equitable Building Society v Inland Revenue Commissioners [1993] AC 70 at 172 per Lord Goff.

[3] to use of the wording of Isaacs J in Sargood Bros v Commonwealth (1910) 11 CLR 258 at 303.

[4] Greg Weeks, ‘The Public Law of Restitution’ (2014) 38(1) Melbourne University Law Review 198 at 200 citing Steven Elliott, Birke Häcker and Charles Mitchell, ‘Introduction’ in Steven Elliott, Birke Häcker and Charles Mitchell (eds), Restitution of Overpaid Tax (Hart Publishing, 2013) 3, 3.

[5] Kozik & Ors v Redland City Council [2021] QSC 233.

[6] see Local Government Act 2009 (Qld) Chapter 4, Part 1.

[7] Local Government Act 2009 (Qld) s 94(1)(a).

[8] Local Government Act 2009 (Qld) s 94(1)(b)(i).

[9] Local Government Act 2009 (Qld) s 94(2).

[10] Local Government Act 2009 (Qld) s 95.

[11] Local Government (Finance, Plans and Reporting) Regulation 2010 (Qld) s 32 (repealed); Local Government Regulation 2012 (Qld) s 98.

[12] Kozik & Ors v Redland City Council [2021] QSC 233 at [111].

[13] Kozik & Ors v Redland City Council [2021] QSC 233 at [88].

[14] In particular, council had omitted to adopt an ‘overall plan’ before, or at the same time as, council resolved to levy the special charges of the Local Government Regulation 2012 (Qld) (after 14 December 2012), and the repealed Local Government (Finance, Plans and Reporting) Regulation 2010 (Qld) (before 14 December 2012).  

[15] Kozik & Ors v Redland City Council [2021] QSC 233 at [39].

[16] Kozik & Ors v Redland City Council [2021] QSC 233 at [41].

[17] other than requiring repayment ‘as soon as practicable’.

[18] Kozik & Ors v Redland City Council [2021] QSC 233 at [99].

[19] Kozik & Ors v Redland City Council [2021] QSC 233 at [90] citing Commonwealth v SCI Operations Pty Limited (1998) 192 CLR 285, 306 per Gaudron J.

[20] See Commonwealth v SCI Operations Pty Ltd (1998) 192 CLR 285 at 317 per McHugh and Gummow JJ.

[21] Woolwich Equitable Building Society v Inland Revenue Commissioners [1993] AC 70.

[22] Woolwich Equitable Building Society v Inland Revenue Commissioners [1993] AC 70 at 172 per Lord Goff.

[23] Prygodicz v Commonwealth (No 2) [2021] FCA 634 at [147] per Murphy J referring to State Bank of New South Wales Limited v Commissioner of Taxation for the Commonwealth of Australia (1995) 62 FCR 371 at 378 per Wilcox J; Chippendale v Commissioner of Taxation (1996) 62 FCR 347 at 366 per Lehane J.

[24] Commentators have explained this to be a product of the ‘somewhat conservative’ nature of Australian courts: Greg Weeks, ‘The Public Law of Restitution’ (2014) 38(1) Melbourne University Law Review 198 at 203.

[25] The approach to determining claims of unjust enrichment in a claim for money had and received was summarised by French CJ, Crennan and Kiefel JJ in Equuscorp Pty Ltd v Haxton (2012) 246 CLR 498 at 516.

[26] Equuscorp Pty Ltd v Haxton (2012) 246 CLR 498 at 516 per French CJ, Crennan and Kiefel JJ.