Joining Foreign Heirs as “Necessary or Proper Parties” for Enforcement-Only Relief: Commentary on The Public Institution for Social Security v Al Rajaan & Ors [2025] EWCA Civ 1505

1. Introduction

This Court of Appeal decision in The Public Institution for Social Security v Al Rajaan & Ors [2025] EWCA Civ 1505 addresses a novel and important question of jurisdiction and party-joinder in cross‑border estate and fraud litigation: can foreign heirs of a deceased defendant be joined to English proceedings, under the “necessary or proper party” gateway for service out, solely so that they are bound by the English court’s determination of the deceased’s liability for the purposes of enforcement abroad, even where no substantive relief is sought against them?

The Court of Appeal (Sir Geoffrey Vos MR giving the leading judgment, with Nugee and Asplin LJJ agreeing) answers “yes”. It holds that:

heirs resident abroad can be “necessary or proper parties” for the purposes of CPR PD6B, para 3.1(3),
even where the only relief sought against them is declaratory / enforcement-oriented (the “Enforcement Basis”),
provided the central liability issue is the same as that to be determined against the estate, and the joinder is necessary to avoid multiplicity of proceedings and to enable effective enforcement in a foreign jurisdiction.

This commentary examines the background, the reasoning of both Jacobs J and the Court of Appeal, the interaction with Swiss universal succession, and the judgment’s implications for cross-border enforcement, estate litigation, and the “necessary or proper party” gateway.

2. Background to the Case

2.1 The Parties and the Underlying Claim

The Claimant, the Public Institution for Social Security (“PIFSS”), is the Kuwaiti state pension fund. It alleges that its long‑serving former Director General, Fahad Al Rajaan (First Defendant), orchestrated substantial corruption schemes between 1984 and 2014, abusing his position to obtain secret commissions for himself and third parties.

Mr Al Rajaan submitted to the jurisdiction and defended the claim while alive. He died on 6 September 2022. His widow, Muna Al Rajaan Al Wazzan (Second Defendant), and their children – the 42nd to 45th defendants, the “Al Rajaan Children” – are his heirs. The trial of PIFSS’s substantial fraud claim is ongoing before Jacobs J and is expected to last close to a year.

2.2 The Cross-Border Estate Dimension

The litigation is complicated by the fact that:

PIFSS’s claim is primarily against the estate of the late Mr Al Rajaan.
He had some assets in England but more substantial assets in Switzerland.
The English assets are plainly insufficient to satisfy any significant judgment debt.
PIFSS therefore anticipates needing to enforce in Switzerland.

For the purposes of this application and appeal, all parties proceeded on the basis that Mr Al Rajaan was domiciled in Switzerland at the time of his death. That assumption imports Swiss succession law – in particular, the civil‑law concept of universal succession, under which heirs automatically succeed to the assets and liabilities of the deceased.

PIFSS does not allege any wrongdoing by the Al Rajaan Children. They are not said to have assisted in, or benefited from, the corruption schemes in a culpable sense. They are joined solely in their capacity as heirs, and PIFSS seeks to involve them to ensure that any English judgment determining their father’s liability will be enforceable against Swiss‑situated assets.

2.3 Procedural History

The key procedural steps were:

On 14 November 2022, Jacobs J appointed Ms Al Wazzan to represent the English estate under CPR 19.12(1)(b).
On 26 March 2023, Henshaw J granted limited ad litem and ad colligenda bona grants, appointing Ms Al Wazzan as administrator of the English estate. She thereby became the personal representative for English‑situate assets.
On 25 April 2024, Jacobs J granted PIFSS permission to join the Al Rajaan Children (and Ms Al Wazzan in her capacity as heir) under CPR 19.2(4) or 19.2(2)(b).
On 11–12 June 2024, PIFSS obtained without‑notice permission to serve the claim form out of the jurisdiction on the Children.
On 23 July 2024, the Children applied to challenge jurisdiction and to set aside service out.

One child, Fajer Al Rajaan (44th Defendant), had been a director of two English companies and had given a London address of their accountants as her address for service. PIFSS served her within the jurisdiction at that address, and relied (if needed) on section 1140 Companies Act 2006 to argue that such service was valid irrespective of her actual residence.

At first instance, Jacobs J:

held that PIFSS had a “good arguable case” that the Children were proper parties on the Enforcement Basis, and
declared (though it was unnecessary) that service on Fajer under s.1140 CA 2006 was valid.

The Children appealed with permission of Jacobs J. Their appeal raised:

Ground 1: No good arguable case that they were “necessary or proper parties” under the Enforcement Basis.
Ground 2: Service on Fajer under s.1140 CA 2006 was invalid (only arising if Ground 1 succeeded).

PIFSS responded with a respondent’s notice, contending that Jacobs J should also have held that there was a good arguable case under the alternative Substantive Basis (i.e. that the heirs were themselves substantively liable under Swiss law as universal successors).

3. Swiss Law: Universal Succession and Enforcement

3.1 Expert Evidence of Swiss Law

PIFSS relied on unchallenged expert evidence from Professor Dominique Jakob (University of Zurich). The Court distilled four key propositions:

Universal succession. Switzerland does not recognise a separate “estate administration” akin to English law. At death, all assets and liabilities pass automatically to the heirs as a group. They form a community of heirs, joint owners and joint and several debtors. No official act or acceptance is required (though heirs can disclaim within a time limit).
No separate legal personality of the estate. The “estate” is not a separate juridical person. As a rule, it cannot sue or be sued. A judgment against “the estate” is not binding on the heirs. A judgment against only one heir binds only that heir’s quota, not the whole community. To bind the entire estate for enforcement, all heirs should be named as defendants.
Jurisdiction assessed at commencement of proceedings. Under Swiss private international law, one looks at the defendant’s domicile or habitual residence at the time the claim is filed, not at the time of judgment. If the foreign court had jurisdiction over the deceased when proceedings were commenced, the later participation (or non‑participation) of heirs as defendants does not negate jurisdiction.
Universal succession extends to procedural aspects. The heirs succeed not only to substantive assets and liabilities but also to the deceased’s procedural situation, including the jurisdictional status of pending proceedings. Where proceedings were properly commenced against the deceased, the same court continues to have jurisdiction over the heirs.

3.2 Enforcement Consequences in Switzerland

For PIFSS, this evidence had a crucial practical implication:

A mere English judgment against “the estate” of Mr Al Rajaan (or against its English administrator) may not be enforceable in Switzerland against all Swiss assets.
Under Swiss law, all individual heirs must be parties to the judgment for the community of heirs to be fully bound, so that the entire asset pool can be reached in execution.

Accordingly, from PIFSS’s perspective, joining the heirs as defendants in the English proceedings is not a matter of choice but a condition for:

obtaining a judgment that will be recognised in Switzerland as binding all heirs, and
avoiding the need to litigate the factual and legal issues afresh in Swiss enforcement proceedings.

4. The Pleaded Bases for Joining the Heirs

4.1 Substantive vs Enforcement Basis

PIFSS’s Particulars of Claim advanced two distinct and alternative bases (17–19):

The “Substantive Basis” (para 12A(a)). If Swiss law governs the estate, then under Articles 560, 603 and 639 of the Swiss Civil Code and related provisions, the heirs are jointly and severally liable as universal successors to the civil liabilities of the deceased. On this footing, PIFSS claims substantive relief against the Children as successors to the tort liabilities of their father.
The “Enforcement Basis” (para 12A(b)). Even apart from any direct substantive liability, PIFSS seeks to join the heirs to ensure that its English judgment is effective and enforceable in relation to Swiss and other assets. The logic is:
- Swiss law governs succession to Swiss immovables (and, depending on domicile and choice‑of‑law, certain movables).
- Foreign jurisdictions may treat the heirs as holding certain assets.
- To obtain an enforceable judgment against those assets, it may be necessary that judgment be entered against the heirs themselves.
The relief here is essentially declaratory, establishing as between PIFSS and the heirs that Mr Al Rajaan was liable.

The Court of Appeal is careful to distinguish the two:

Under the Substantive Basis, PIFSS would be seeking a money judgment directly against the heirs as successors.
Under the Enforcement Basis, PIFSS merely seeks:
a binding determination as between PIFSS and the Al Rajaan Children of Mr Al Rajaan's liability. It is not to obtain a determination ... of any liability of the Al Rajaan Children to satisfy a judgment against Mr Al Rajaan's estate. [19]

Jacobs J had found the Substantive Basis “by no means straightforward” but upheld jurisdiction under the Enforcement Basis. On appeal, the Children’s primary target was the Enforcement Basis (Ground 1), with the Substantive Basis only in play via PIFSS’s respondent’s notice.

5. The Jurisdictional Question: “Necessary or Proper Party” Gateway

5.1 The Gateway and the Test

Because the Children are resident outside England & Wales, PIFSS needed the court’s permission to serve them out of the jurisdiction (CPR 6.36). For that, it had to show a “good arguable case” that the claim against them fell within one of the jurisdictional “gateways” in CPR PD 6B para 3.1.

PIFSS relied on Gateway 3, which covers a claim where:
“a claim is made against a person (‘the anchor defendant’) who has been or will be served within the jurisdiction and … another person is a necessary or proper party to that claim.”

The classic test for a “necessary or proper party” comes from Lord Collins in Altimo Holdings and Investment Ltd v Kyrgyz Mobil Tel Ltd [2011] UKPC 7; [2012] 1 WLR 1804 at [87], adopted here at [16]:

“... the question whether D2 is a proper party is answered by asking: ‘supposing both parties had been within the jurisdiction would they both have been proper parties to the action?’ … D2 will be a proper party if the claims against D1 and D2 involve one investigation … [or if they are] ‘closely bound up’ [or involve] ‘a common thread’ …”

Thus, the essential inquiry is a hypothetical:

If both the estate and the heirs had been present in England,
would it have been proper to join the heirs under CPR 19.2, because the claims raised a common investigation or were closely interwoven?

If so, they are “proper parties” and can be served out under Gateway 3, subject to the usual additional requirements (serious issue, forum conveniens). The Children did not run distinct arguments on serious issue or forum beyond those tied to the gateway point.

6. English Law on Estates, Administration and Foreign Representatives

6.1 Six Propositions of English Law

The Children’s argument on Ground 1 rested on six orthodox propositions, none disputed by PIFSS ([24]–[29]):

Administration vs succession distinguished. English law distinguishes clearly between:
- the administration of an estate (collecting assets, paying debts, distributing residue), and
- succession (who ultimately becomes entitled to the property).
See Viegas v Cutrale [2024] EWCA Civ 1122; [2025] 1 WLR 1467 at [118].
Executors’/administrators’ duty to pay debts. As Uthwatt J explained in Re Tankard [1942] Ch 69 at 72, it is the executors’ duty, as part of the due administration of the estate, to pay the testator’s debts with due diligence out of the assets properly available. Matters concerning collection and debt‑payment are “administration of estates” (Viegas at [120]).
Survival of causes of action against the estate (1934 Act). By section 1(1) of the Law Reform (Miscellaneous Provisions) Act 1934, all causes of action subsisting against (or vested in) a deceased (with narrow exceptions, e.g. purely personal claims, defamation) survive for or against their estate. Hence, claims based on pre‑death causes of action are properly brought against the personal representative: see High Commissioner for Pakistan v NatWest [2015] EWHC 3052 (Ch) at [29].
Liabilities as provable debts in administration. Section 1(6) of the 1934 Act treats such liabilities, even if for unliquidated damages in tort, as debts provable in the estate administration.
Territorial reach of English grants. An English grant of representation extends only to property locally situate in England at the time of death (and movables later brought here): Dicey, Morris & Collins, Rule 156. The administration of the English estate is governed by English law: Rule 158; Viegas at [99]–[100].
Foreign personal representatives have no status in England. A grant or authority under foreign law has no operation in England: Dicey, Rule 159. A foreign personal representative cannot, in that capacity, sue or be sued in England: Dicey, Rule 160; Degazon v Barclays Bank International Ltd [1988] 1 FTLR 17.

6.2 The Children’s Core Argument from These Propositions

The Children argued that these principles lead to two conclusions:

The only proper defendant to PIFSS’s claim is the English personal representative (here, Ms Al Wazzan, as administrator of the English estate). As a matter of English law, the “estate” is represented solely through her; heirs have no place in purported litigation on estate liabilities.
Because the English administrator’s authority is territorially limited to English assets, the English court cannot make orders directed at foreign successors in respect of foreign assets. To do so would be conceptually inconsistent with the limited reach of English administration and with the prohibition on suing foreign representatives as such.

They added a more principled objection: it is wrong in principle to join parties solely to bind them to a result where no substantive claim lies against them and they lack any real connection to the conduct giving rise to the litigation (here, the alleged corruption).

7. The Court of Appeal’s Reasoning

7.1 Identifying the Real Issue Between PIFSS and the Heirs

The Court of Appeal rejects the Children’s submissions and endorses Jacobs J’s approach. The critical step in the reasoning appears at [32]:

“Given that the Al Rajaan Children decline either to admit that Mr Al Rajaan was liable to PIFSS as alleged or to accept the English court's determination of that liability, the same issue arises as between PIFSS and the Al Rajaan Children as it does between PIFSS and Mr Al Rajaan's estate: was Mr Al Rajaan liable to PIFSS as alleged? … That issue should only have to be determined once.”

The Court emphasises:

There is a concrete live dispute between PIFSS and the Children: they reserve the right to dispute liability in Swiss enforcement proceedings and refuse to be bound by the English court’s determination.
That dispute is identical to the issue already being tried: whether the late Mr Al Rajaan was liable to PIFSS in tort.
In light of the Swiss law evidence, PIFSS may have to litigate that very issue again in Switzerland if the Children are not bound by the English judgment.

From the perspective of the Altimo test, the claims against:

the estate (through the administrator), and
the Children (as heirs),

involve “one investigation” and are “closely bound up” with a common thread: determination of the deceased’s liability.

The Court concludes at [34] that, had the Children been physically present within the jurisdiction, it would have been proper under CPR 19.2(2)(b) to join them so that the same liability issue could be resolved in their presence:

“Otherwise … the issue of Mr Al Rajaan’s liability would have to be determined all over again after having been determined at vast expense in these proceedings when it came to enforcement of the judgment.”

7.2 Preserving the Distinction Between Administration and Succession

The Court is careful to state that this approach does not collapse the English distinction between administration and succession ([33]):

“Determination of Mr Al Rajaan’s liability to PIFSS as between PIFSS and the Al Rajaan Children does not involve the English court determining any issue as to succession.”

In other words:

The English court is not:
- deciding which heirs have taken which assets,
- ruling on the validity or timing of any disclaimer of inheritance, or
- determining how Swiss succession rules distribute property.
Those questions remain for the Swiss courts applying Swiss law.

The English court confines itself to a determination of liability in tort (a pre‑death cause of action under English law), and it simply allows that determination to be binding inter partes as between PIFSS and the heirs. What the Swiss courts then do with that determination in recognising and enforcing an English judgment is a matter for Swiss law and Swiss procedure.

7.3 Joinder to Bind a Party to a Determination: Analogies and Principle

The Court agrees with Jacobs J that there is no objection of principle to joining a party to a claim in order to ensure that they are bound by the court’s determination, where appropriate ([35]). It notes several familiar examples where the court permits joinder even though the joined party is not the primary or obvious target of substantive relief:

Chabra jurisdiction. In freezing injunction cases, third parties holding assets that are arguably beneficially owned by a defendant can be joined as “Chabra” defendants, even though no cause of action is alleged against them. The purpose is to ensure that they are bound by the court’s orders regarding assets.
Joinder of assignors. Where an assignee sues on an assigned cause of action, the court may join the assignor so that any issue (e.g. as to title or validity) is conclusively determined inter partes and the defendant is protected from double jeopardy.
Orders under CPR 19.13. This rule allows the court to add a person as a party where it is desirable to do so so that the court can resolve all the matters in dispute in the proceedings.

These examples are not directly analogous, but they illustrate what the Court calls the “broader principle”: the court may join parties with a real interest in, or exposure to, the subject matter of a determination, even where the direct substantive claim may fall elsewhere, so as to ensure finality and avoid multiplicity of litigation ([35]).

The Court notes (citing Sanders Lead Co Inc v Entores Metal Brokers Ltd [1984] 1 WLR 452 and HMRC v Gresh [2009–10] GLR 239) that this is effectively the flip side of the more familiar situation where interested parties intervene voluntarily to protect their position in ongoing proceedings.

7.4 Application to the Gateway: Heirs as “Proper Parties”

Having concluded that, if present in the jurisdiction, the Children could properly be joined so that the liability issue is decided once and for all as between all interested parties, the Court holds that they are “proper parties” within the meaning of Gateway 3 ([36]):

“Given that it would be proper to join the Al Rajaan Children as defendants if they were present in the jurisdiction ... it follows that they are proper parties to the claim within Gateway 3.”

In reaching this conclusion, the Court indicates that its reasoning is consistent with that of Foxton J in Commercial Bank of Dubai PSC v Al Sari [2024] EWHC 3304 (Comm) at [273]–[280], where similar jurisdictional issues about joining third parties to bind them to determinations had been discussed.

7.5 The Substantive Basis and s.1140 CA 2006 Left Open

Because the Court upholds jurisdiction on the Enforcement Basis:

It is unnecessary to decide whether PIFSS also has a good arguable case on the Substantive Basis, i.e. whether the heirs are themselves directly and substantively liable under Swiss universal succession so as to support a money judgment against them ([37]).
Ground 2 (validity of service on Fajer under section 1140 Companies Act 2006) likewise does not arise, and the Court declines to decide it ([38]). The first-instance declaration that service was valid remains, but there is no appellate pronouncement on the contested s.1140 issue.

The appeal is therefore dismissed on the single ground that the heirs are properly joined under the Enforcement Basis and are within the “necessary or proper party” gateway.

8. Summary of the Judgment

8.1 Outcome

The Court of Appeal unanimously:

Dismisses the Al Rajaan Children’s appeal.
Holds that:
- PIFSS has a good arguable case that the Children are “necessary or proper parties” under Gateway 3 of PD 6B for service out,
- based solely on the Enforcement Basis (i.e. to bind them to the determination of their father's liability),
- without needing to decide the more ambitious Substantive Basis.
Makes no determination on the validity of service under s.1140 CA 2006.

8.2 Core Holding (New Precedent)

The key principle established is that:

Where foreign heirs of a deceased defendant are, under foreign law, the persons who will own and control assets against which an English judgment may need to be enforced, and they do not accept the binding effect of the English court’s determination of the deceased’s liability, they can be joined as defendants under CPR 19.2 and served out under the “necessary or proper party” gateway, even if the only relief sought against them is declaratory in nature (an “enforcement-only” basis) and they are not alleged to be wrongdoers.

9. Precedents and Authorities: Their Role and Interaction

9.1 Altimo and the “One Investigation” Test

Altimo Holdings v Kyrgyz Mobil Tel provides the authoritative formulation of the “necessary or proper party” test. The Court applies it straightforwardly:

The claims against the estate and against the heirs involve a single central issue: was the deceased liable?
Both sets of claims would have been joined in one action if all parties were within the jurisdiction.
There is clear “common thread” and a unified “investigation”.

Thus, Altimo supports rather than constrains the Court’s willingness to bring the heirs into the proceedings.

9.2 Viegas v Cutrale and the Administration/Succession Divide

Viegas v Cutrale confirms the structural separation in English law between:

administration of estates (a procedural/managerial function undertaken by personal representatives), and
succession (who ultimately takes the property under domestic or foreign succession rules).

The Children invoked this to argue that heirs had no place in litigation about the debts of the deceased, which should run only against the administrator and the English estate.

The Court accepts the distinction but holds that joining heirs for liability determination does not trespass into succession. The English court is not reallocating property or determining heirship; it is deciding the underlying cause of action in tort. Viegas is thus reconciled, not displaced.

9.3 Re Tankard, the 1934 Act, and the Proper Defendant to Pre-Death Liabilities

Re Tankard and the Law Reform (Miscellaneous Provisions) Act 1934 make clear that:

after death, pre‑existing causes of action are enforceable against the estate,
the personal representative is the correct defendant, and
such liabilities are treated as provable debts in the administration.

The Court does not dilute this. It agrees that, as a matter of English substantive law, the primary target for the claim is the estate via the administrator. The novelty is that it recognises a separate jurisdictional and procedural dimension: a claimant may need to add heirs as parties in order to ensure transnational effectiveness of the English judgment. This is additional to, not a replacement for, suing the administrator.

9.4 Dicey, Degazon and the Limits of Foreign Representation

Dicey’s Rules 156–160 and Degazon v Barclays underline the inability of foreign personal representatives to act (or be sued) in England by virtue of their foreign status alone. The Children argued that by a similar token, foreign heirs occupying an analogous position under foreign law could not be proper defendants in English estate litigation.

The Court rejects this extension. Foreign representatives are excluded because they derive their authority from a foreign grant that has no operation in England. By contrast, the heirs here are sued not as foreign personal representatives but as persons with a direct and legal interest in assets against which enforcement may be sought and who will, as a matter of Swiss law, be the parties against whom Swiss enforcement must proceed. They are therefore not strangers; they are at the core of any future enforcement battle.

9.5 Commercial Bank of Dubai v Al Sari and the Recognition of Enforcement-Driven Joinder

The Court references Foxton J’s reasoning in Commercial Bank of Dubai PSC v Al Sari [2024] EWHC 3304 (Comm) at [273]–[280], which dealt with the tactical and jurisdictional propriety of joining parties to ensure effectiveness of relief. Although that case is not quoted in detail, its mention signals that the Court’s approach fits within a developing body of authority recognising enforcement-oriented joinder as legitimate.

9.6 Chabra, Assignors and CPR 19.13: Illustrations of the “Broader Principle”

The Court’s invocation of the Chabra jurisdiction, assignor joinder, and CPR 19.13 is important symbolically: it reflects an overarching judicial willingness to shape procedural tools so that:

all relevant parties are before the court,
issues are decided once, and
outcomes are practically enforceable.

Just as a Chabra defendant may be joined to preserve assets for enforcement of a judgment against the primary wrongdoer, so here the heirs are joined to ensure that the English judgment has realistic enforceability in Switzerland. The judgment thus forms part of a broader trend of giving robust, pragmatic content to joinder rules in the transnational context.

10. Complex Concepts Simplified

10.1 Universal Succession (Swiss Law)

In many civil law countries (including Switzerland), when someone dies:

there is no separate legal “estate” as an entity; and
all assets and liabilities pass immediately and automatically to the heirs as co‑owners and co‑debtors.

This is called universal succession. The heirs “step into the shoes” of the deceased for all rights and obligations, collectively.

10.2 Administration vs Succession (English Law)

In England & Wales:

A person’s estate is first gathered, managed, and distributed by personal representatives (executors or administrators). This is the administration of the estate.
Only after debts and expenses are paid, the remainder is transferred to heirs/beneficiaries. Who gets the remainder is the question of succession.

Crucially, creditors sue the personal representative, not the heirs, because the estate (through the PR) is the debtor until distribution.

10.3 “Necessary or Proper Party” Gateway (PD 6B para 3.1(3))

The English court can allow service out of the jurisdiction on a foreign defendant if:

There is a claim against an “anchor defendant” who is (or will be) served within England & Wales, and
The foreign defendant is a “necessary or proper party” to that claim.

The foreign defendant is a proper party if, had they both been in England, it would have been proper to join them in one action so that:

the claims involve one common investigation, or
there is a close connection/common thread between the issues against both defendants.

10.4 Good Arguable Case

To use any gateway, the claimant must show a “good arguable case” that the claim falls within it. This is a relatively low, but not trivial, threshold: the claimant must have the better of the argument on the evidence available, but does not need to prove the point conclusively.

10.5 Declaratory / Enforcement-Only Relief

A declaration is a court order stating the legal position between the parties (e.g., that X is liable to Y), without directly ordering payment or performance.

An enforcement-only claim is where:

the claimant’s immediate object is not to get a money judgment against that defendant, but
to obtain a determination that will later help in enforcing a judgment (perhaps in a foreign court) against assets they hold or may hold.

In this case, the relief against the heirs is essentially declaratory: a binding determination that their father was liable, so that Swiss courts will treat that liability as established vis-à-vis the heirs.

10.6 Chabra Jurisdiction

Under the Chabra jurisdiction, named after an English case, the court can:

add a third party as a defendant solely because they hold assets that are realistically the defendant’s assets, and
freeze those assets (and make related orders) to ensure enforcement of a future judgment against the primary defendant.

The third party need not be alleged to have committed any wrong; the joinder is essentially enforcement-driven.

10.7 Limited Grants ad litem and ad colligenda bona

These are special, often temporary, grants of representation:

ad litem: to enable the representative to conduct litigation on behalf of the estate.
ad colligenda bona: to collect and preserve the estate’s assets until a full grant is made.

They allow the court to ensure there is someone with standing to sue or be sued on behalf of the estate, even where the full administration is not yet in place.

11. Impact and Future Significance

11.1 Cross-Border Enforcement Against Estates

The decision will be of substantial importance in cases where:

the deceased had significant foreign assets,
foreign succession law employs universal succession or similar concepts, and
foreign law conditions the enforceability of a foreign judgment on all heirs being party to the judgment.

Claimants can now be more confident that:

English courts will permit joinder of foreign heirs as defendants at the liability stage, even though they are not alleged wrongdoers, so that
the English judgment has a realistic prospect of being recognised and enforced against foreign estate assets.

This may significantly enhance the attractiveness of England & Wales as a forum for complex fraud and asset‑recovery claims where the alleged wrongdoer dies mid‑litigation and holds a multi‑jurisdictional asset base.

11.2 Clarifying and Expanding the Scope of the “Necessary or Proper Party” Gateway

The judgment clarifies that the “necessary or proper party” gateway:

is not confined to cases where substantive relief is sought against the foreign party, and
can extend to defendants joined principally for enforcement or binding-effect purposes, provided:
- they have a genuine legal interest or exposure, and
- the central liability issue is common and will likely recur in enforcement proceedings.

This reflects, and may accelerate, a broader trend in English private international law towards:

procedural pragmatism,
focus on effectiveness of judgments, and
willingness to use joinder powers to avoid fragmented, duplicative litigation in multiple jurisdictions.

11.3 Preserving Comity and Respecting Foreign Succession Law

While robust, the approach is sensitive to international comity:

The English court does not decide who the heirs are, what shares they take, or whether disclaimers are valid.
It decides only the liability question in tort, which is an English law issue in proceedings properly commenced against the deceased.
It leaves it to the Swiss courts to determine how to recognise and enforce the English judgment in light of Swiss universal succession rules.

Thus, the case offers a model of how an English court can work with, rather than against, foreign legal systems to produce a judgment that is both principled and practical.

11.4 Unresolved Questions: Substantive Liability of Heirs and s.1140 CA 2006

Two significant issues remain open for future cases:

Substantive liability of heirs as universal successors. The Court does not decide whether foreign heirs can be held substantively liable in England as successors to the deceased’s obligations under foreign universal succession rules, as PIFSS alleged under the Substantive Basis. That potentially raises complex conflict‑of‑laws questions (e.g. whether and how English courts characterise and give effect to foreign rules making heirs directly liable).
Scope of section 1140 Companies Act 2006. The status of service on foreign‑resident directors at an English address under s.1140 remains unsettled at appellate level. First‑instance decisions have taken a robust view allowing such service without permission for service out, but this judgment intentionally does not resolve the point.

Both matters are likely to re‑emerge in future litigation and may generate further appellate jurisprudence.

11.5 Practical Guidance for Litigants

In light of this decision, practitioners dealing with deceased defendants and foreign assets should:

Obtain early expert evidence on the foreign law of succession and enforcement (as PIFSS did with Professor Jakob), to identify:
- who must be party to a judgment for it to be enforceable abroad, and
- whether heirs or other successors may need to be joined.
Consider framing claims against heirs, where appropriate, on an Enforcement Basis, particularly in civil law / universal succession jurisdictions.
Use the necessary or proper party gateway to bring foreign heirs within the English jurisdiction, explaining clearly the common “one investigation” and the risk of re‑litigation abroad.
Avoid overreaching: this judgment does not license joinder of “random” or purely tangential parties; the heirs here were the core persons on whom enforcement would fall.

12. Conclusion

PIFSS v Al Rajaan [2025] EWCA Civ 1505 is a significant development in the law of civil jurisdiction, party‑joinder and cross‑border estate enforcement. The Court of Appeal confirms that foreign heirs can be joined as “necessary or proper parties” where the only relief sought against them is to bind them to the determination of the deceased’s liability, provided they are genuinely implicated as the persons against whom foreign enforcement will be pursued, and the liability issue is common.

The judgment:

reconciles this approach with the traditional English distinction between administration and succession,
aligns with existing authorities on necessary or proper parties and enforcement‑oriented joinder (Chabra, CPR 19.13, Al Sari),
respects foreign legal frameworks (here, Swiss universal succession and enforcement law), and
strengthens the practical utility of English judgments in complex, multi‑jurisdictional fraud and estate disputes.

While leaving open important questions about substantive successor liability and the reach of s.1140 Companies Act 2006, the case sets an important precedent for how English courts will approach foreign heirs and enforcement‑driven joinder in the years to come.