Gluck v Endzweig & Anor: Unlimited “Amend at Any Time” Clauses Are Repugnant to Arbitral Finality Under the Arbitration Act 1996

1. Introduction

Gluck v Endzweig & Anor ([2026] EWCA Civ 145) is a Court of Appeal decision about the boundary between party autonomy in arbitration and the statutory requirement of finality under the Arbitration Act 1996.

The dispute arose from a June 2019 share purchase agreement (“SPA”) under which Mr David Gluck sold 50% of Net Pex Ltd to Evertop Limited, with Mr Chaim Yaakov Endzweig guaranteeing instalments of the purchase price. The SPA contained an arbitration clause requiring disputes to be “finally resolved by arbitration by the Beth Din”.

After disagreement about a profit-based price-reduction mechanism (Schedule 7), the parties signed a further “arbitration agreement” appointing Rabbis as arbitrators. It stated both (i) that the deed would be valid according to the Arbitration Act and (ii) that the Beth Din had authority to “amend and add to and change the Judgement they have given, at any time” (the Court’s term: the “unlimited amendment clause”).

The key issue was whether that unlimited amendment clause could coexist with an arbitration intended to be enforceable under the Arbitration Act—particularly given the Act’s structure around awards being final and binding and the limited, time-bounded correction regime in section 57.

2. Summary of the Judgment

The Court of Appeal allowed Mr Gluck’s appeal and restored the section 66 enforcement order originally granted by HHJ Pelling KC.

  • The unlimited amendment clause, if given effect, would mean an award could be altered indefinitely and would therefore never become reliably final and enforceable. That is incompatible with an “arbitration agreement” under the Arbitration Act.
  • Section 57 could not “save” the clause: the default time limits cannot be reconciled with “at any time”, and party agreement cannot eliminate finality.
  • Applying ordinary contractual principles on repugnant/inconsistent terms, the unlimited amendment clause was repugnant to the agreement’s core purpose (final resolution by arbitration) and had to be rejected, leaving the remainder of the arbitration agreement effective.
  • With the unlimited amendment clause severed/rejected, the default section 57 regime applied; it was common ground that its time limits were not complied with. Therefore the Beth Din’s Second Award was final and enforceable, and the later Third Award (an “amended” award) could not justify setting aside enforcement.

3. Analysis

3.1 Precedents Cited

Teare J K v S [2015] EWHC 1945

The Court referenced Teare J K v S [2015] EWHC 1945 when explaining what “unless otherwise agreed” in section 58(1) is generally aimed at: allowing parties to adopt institutional arbitration rules under which an award may be subject to an internal review mechanism (for example, scrutiny by an arbitral institution) before it is treated as final.

Importantly, the Court treated that kind of review as consistent with finality because it is structured to culminate in a final award. The reference helped the Court distinguish legitimate “review” processes from an agreement that leaves the tribunal free to change an award indefinitely.

IS Prime Ltd v TF Global Markets (UK) Ltd [2020] EWHC 3375 (Comm), [2021] Bus LR 493

The Court relied heavily on IS Prime Ltd v TF Global Markets (UK) Ltd [2020] EWHC 3375 (Comm), [2021] Bus LR 493 for a foundational proposition: parties cannot agree to a process that is “arbitration” in name but whose product “will not resolve their dispute and will neither be nor ever become binding upon them” and still call it an arbitration agreement.

This authority was used to anchor the Court’s central conclusion: an “unlimited amendment” power that prevents any point of stable finality is inconsistent with the essential nature of arbitration under the Act.

Other materials referenced

  • Departmental Advisory Committee Report on the Arbitration Bill, February 1996 (the DAC report): cited for the principle later reflected in section 1(b)—party autonomy.
  • Mustill & Boyd (2nd ed.): referenced for the long-recognised requirement that arbitration contemplates a binding decision.

3.2 Legal Reasoning

(a) Starting point: party autonomy—but within the architecture of the Act

The Court accepted the strong pro-arbitration approach required by section 1, particularly: (a) fair resolution without unnecessary delay, (b) party autonomy subject to safeguards, and (c) non-intervention. It emphasised that courts should try, where possible, to give effect to the whole agreement so the chosen arbitral mechanism works.

(b) The incompatibility: “amend … at any time” destroys finality

The arbitration agreement contained two intentions in tension:

  • Enforceability under the Arbitration Act (“this deed will be valid according to the Arbitration Act”).
  • Unlimited tribunal freedom (“amend and add to and change the Judgement … at any time”).

The Court held the second intention cannot be implemented in a way that preserves the first. If an award can be changed “at any time”, then: (i) there is no dependable moment when an award is final, and (ii) enforcement under section 66 becomes conceptually unstable because the award might be changed after enforcement. Arbitration, however, requires a binding outcome capable of enforcement.

(c) Why “functus officio” and “draft-until-confirmed” did not cure the problem

HHJ Keyser KC’s approach relied on the Beth Din declaring itself functus officio (i.e., its mandate ended). The Court of Appeal rejected this as a solution because the unlimited amendment clause would allow the Beth Din to change even that decision: the “end point” could always be reopened.

Similarly, treating awards as “draft” until a final confirmation was also vulnerable: the clause still permitted later reconsideration even after confirmation. The problem was not merely procedural uncertainty; it was a contractual grant of never-ending jurisdiction to revise.

(d) Why section 57 could not validate the clause

Section 57 is non-mandatory and allows parties to agree on the tribunal’s correction/additional award powers. But the Court held that any such agreement is subject to an implied requirement that the award must become final at some stage.

The Court examined whether the default regime could fill the “gap” as to time limits. It concluded it could not:

  • Even if the clause fell within section 57(1), “at any time” is inconsistent with the Act’s time-bounded correction structure and with finality under section 58.
  • Section 57(4)–(6) contemplate short, defined windows (28/56 days, subject to agreed extension). The Court indicated extensions cannot be indefinite if finality is to be preserved; but “at any time” is, in effect, indefinite.

(e) Repugnancy and severance: rejecting the clause to preserve the arbitration agreement

Applying the Chitty principle cited by the Court (“where parts are inconsistent, give effect to what carries out the purpose and reject what defeats it”), the Court held the unlimited amendment clause was repugnant to the parties’ overarching bargain: disputes would be “finally resolved” by arbitration and result in an award capable of court enforcement.

The Court therefore rejected the clause and preserved the rest of the arbitration agreement. It also rejected the respondent’s fallback position that the parties had “contracted out” of the Act so that awards were enforceable only at common law: the SPA and arbitration agreement clearly signalled an intention to arbitrate under the Act and obtain section 66 enforceability.

(f) Disposition: the Second Award was enforceable; setting aside enforcement was wrong

Once the unlimited amendment clause fell away, only the section 57 default regime could support amendments. It was common ground that the default time limits were not effectively used to amend the Second Award. Accordingly, the Second Award stood as final and enforceable, and HHJ Keyser KC should not have set aside the section 66 enforcement order.

3.3 Impact

(a) Drafting of arbitration agreements (especially faith-based tribunals)

The decision sends a clear message: parties may respect a tribunal’s moral/religious authority, but if they want a legally enforceable arbitration under the Arbitration Act, they must not contract for an arbitral power of revision that prevents awards from reaching finality.

Clauses purporting to permit a tribunal to “amend” awards indefinitely risk being treated as repugnant and disregarded—leaving only the Act’s default correction mechanisms.

(b) Limits of party autonomy under section 1(b)

The judgment illustrates that party autonomy is not a licence to redefine arbitration into a perpetually revisable process. Finality is treated as an irreducible feature of arbitration under the Act.

(c) Enforcement strategy and section 66 applications

Practically, the case encourages careful attention to whether an award is “final” when seeking section 66 enforcement—particularly where the tribunal indicates ongoing review. While the appeal succeeded on the repugnancy analysis, the factual narrative (including the tribunal’s communications about review) highlights that “finality” disputes can derail enforcement and generate satellite litigation.

4. Complex Concepts Simplified

  • Section 66 (enforcement): a streamlined court route to enforce an arbitral award as if it were a judgment.
  • Final and binding (section 58): the award must ultimately settle the dispute so parties can rely on it and enforce it.
  • Section 57 (correction/additional award): limited powers to correct slips/ambiguities or address claims not dealt with, generally within strict time windows.
  • Functus officio: once a tribunal has finally decided the matters within its mandate, it is “done” and has no further authority—unless the Act or a valid agreement gives a limited residual power.
  • Repugnant clause: a term that contradicts the contract’s core purpose so strongly that, to make the contract work, the law rejects that term while preserving the rest (where possible).
  • Section 68 (serious irregularity): a court challenge route alleging serious procedural unfairness/defect in the arbitration that causes substantial injustice.

5. Conclusion

Gluck v Endzweig & Anor establishes that an arbitration agreement governed by the Arbitration Act cannot validly confer an unlimited power on the tribunal to “amend … at any time” because it undermines the essential requirement that arbitration produces a final, binding, enforceable award.

Where such a clause appears alongside a clear intention to arbitrate under the Act and obtain section 66 enforcement, the court may treat the clause as repugnant and reject it, leaving the statutory default correction regime to govern any amendments. The result in this case was that the Beth Din’s Second Award remained enforceable, and the enforcement order should not have been set aside.