How the English Arbitration Act 2025 Governs London-Seated Arbitral Proceedings
Updated August 15, 2026
The Arbitration Act 2025 — in force since 1 August 2025, and applying to arbitrations commenced (and related court proceedings and awards) on or after that date — amends the Arbitration Act 1996 rather than replacing it. Its practical effect on any London-seated arbitration, whether administered by the LCIA, the ICC, or conducted ad hoc, comes down to five changes: a new default rule on the law governing the arbitration agreement, a mandatory codified disclosure duty for arbitrators, a streamlined section 67 jurisdictional-challenge procedure, an express statutory summary disposal power, and strengthened arbitrator immunity.
What the Arbitration Act 2025 Actually Changed
What law governs the arbitration agreement now?
New section 6A of the 1996 Act provides that, absent the parties' express agreement to the contrary, the law applicable to the arbitration agreement is the law of the seat. In practice, for a London-seated arbitration with no express choice of law for the arbitration clause itself, English law now applies to that clause by statutory default. This replaces the more nuanced common-law position that previously applied following the Supreme Court's decision in Enka v Chubb, and is expected to reduce the number of preliminary disputes over which law governs the arbitration agreement before the underlying dispute is even reached. Party autonomy is preserved throughout — section 6A only operates as a fallback where the parties have not made an express choice.
What must arbitrators disclose, and can parties waive it?
The Act codifies the duty recognized by the Supreme Court in Halliburton v Chubb: an arbitrator, or a person approached about a potential appointment, must disclose as soon as reasonably practicable any circumstances that might reasonably give rise to justifiable doubts as to their impartiality in relation to the proceedings or potential proceedings. This duty is mandatory and applies regardless of any contrary agreement by the parties — it cannot be contracted out of.
How did section 67 jurisdictional challenges change?
Section 67 allows a party to challenge an award on the basis that the tribunal lacked substantive jurisdiction. Previously, the range of remedies available on a successful challenge was inconsistent depending on the type of challenge brought. The 2025 Act brings consistency: where a section 67 challenge succeeds, the court can now remit the matter to the tribunal for reconsideration, the same remedy already available for other types of challenge — reducing the extent to which a successful jurisdictional challenge forces a complete re-litigation from scratch.
What is the new summary disposal power?
New section 39A confirms a tribunal's power to issue an award on a summary basis, on the application of a party, unless the parties have agreed otherwise. The threshold mirrors English civil procedure: after giving each party a reasonable opportunity to put forward its case, the tribunal can dispose of a claim, defence, or issue if it considers that a party has no real prospect of success on it. For a London-seated LCIA arbitration, this sits alongside — not in place of — the LCIA's own early determination power under Article 22.1(viii), giving counsel two overlapping routes to the same practical outcome.
What changed for arbitrator immunity?
Arbitrators are no longer liable for costs arising from their own resignation, unless the resignation is shown to have been unreasonable. Separately, in applications for the removal of an arbitrator, the arbitrator is no longer liable for costs unless it is shown that they acted in bad faith. Together, these changes reduce the personal financial risk an arbitrator faces for resigning appropriately — for example, over a genuine conflict — and discourage tactical removal applications aimed at pressuring an arbitrator rather than genuinely addressing misconduct.
Does this apply to an arbitration clause signed years ago?
Yes, in the sense that matters. The Act amends the statutory backdrop that applies to London-seated arbitration generally — it does not require any amendment to existing arbitration clauses. The relevant trigger is the commencement date of the arbitration itself: the reforms apply to arbitrations commenced on or after 1 August 2025, along with related court proceedings and awards, regardless of when the underlying contract or arbitration clause was originally signed.
Real-World Scenario: A Clause Drafted Before the Reform, a Dispute Filed After It
A supply agreement signed in 2019 names London-seated LCIA arbitration but says nothing about which law governs the arbitration clause itself. A dispute arises, and a Request for Arbitration is filed in September 2025 — after the Act's commencement date, even though the contract itself pre-dates the reform.
| Reform | Position Before 1 Aug 2025 | Position Under the 2025 Act | Effect on This Clause |
|---|---|---|---|
| Governing law of the arbitration agreement | Fact-specific common-law test (Enka v Chubb) | Statutory default: law of the seat (s.6A) | English law governs the arbitration clause by default, since the arbitration commenced after 1 Aug 2025 |
| Arbitrator disclosure | Common-law duty (Halliburton v Chubb) | Codified, mandatory statutory duty | No difference in substance, but now unwaivable by agreement |
| Summary disposal | No independent statutory power | Section 39A "no real prospect of success" power | A weak counterclaim can now be tested under both s.39A and LCIA Art. 22.1(viii) |
| Section 67 challenge remedy | Remittal not consistently available | Remittal available on a successful challenge | Lower risk of a full restart if jurisdiction is later successfully challenged |
Step-by-Step Compliance and Drafting Checklist for Counsel
- Check the commencement date of any live or prospective arbitration against 1 August 2025. This determines which regime applies, regardless of when the underlying contract was signed.
- Decide whether to expressly displace the section 6A default in new contracts. If a different law should govern the arbitration agreement itself, say so explicitly rather than relying on the statutory fallback.
- Build disclosure-duty awareness into arbitrator nomination and vetting. Since the duty cannot be excluded, treat it as a fixed input to conflict checks, not a negotiable term.
- Consider a summary disposal application early where a claim or defence is genuinely weak. Section 39A gives a fresh, independent statutory route to test this, alongside any institutional early-determination power.
- Anticipate that a section 67 challenge is now less of a full do-over. Factor the availability of remittal into the litigation-risk assessment of any jurisdictional objection.
- Update template clauses and internal playbooks to reflect the reformed immunity position when advising arbitrators on resignation decisions.
Strategic Takeaway
The Arbitration Act 2025 is deliberately evolutionary, not revolutionary — it fine-tunes a statute that was already considered a strong foundation for London-seated arbitration rather than restructuring it. For practitioners, the practical impact is concentrated in three places: fewer preliminary fights over governing law thanks to section 6A, a genuine second route to early disposal of weak claims via section 39A that runs alongside institutional mechanisms like LCIA Article 22.1(viii), and lower downside risk on a jurisdictional challenge given the now-consistent availability of remittal under section 67. None of this requires renegotiating existing arbitration clauses, but it does justify revisiting how counsel advises on governing-law silence and on early dismissal strategy for any arbitration commenced on or after 1 August 2025.
Sources & Further Reading
- Arbitration Act 2025 (amending the Arbitration Act 1996), including sections 6A and 39A, and the amendments to section 67 and to arbitrator immunity
- The Arbitration Act 2025 (Commencement) Regulations 2025
- Enka Insaat Ve Sanayi AS v OOO Insurance Company Chubb [2020] UKSC 38
- Halliburton Company v Chubb Bermuda Insurance Ltd [2020] UKSC 48
Practical Next Steps
Before advising on a new London-seated arbitration clause, decide deliberately whether to rely on the section 6A default or displace it with an express choice of law for the arbitration agreement, and build that decision into the firm's template clauses. For any arbitration already underway or about to commence, confirm which side of 1 August 2025 the proceedings fall on, since that determines which version of sections 67 and the immunity provisions applies. Because the interaction between section 39A and institution-specific early-determination powers is still a developing area of practice, have counsel with current Arbitration Act 2025 experience review any summary disposal strategy before it is filed.
This article is general legal information, not legal advice. Laws differ by country and change over time — consult a qualified lawyer licensed in your jurisdiction before acting.
Key Takeaways
- Section 6A: absent express agreement, the law governing the arbitration agreement is the law of the seat — reversing the more fact-specific common-law default from Enka v Chubb.
- The disclosure duty is now codified and mandatory — it cannot be excluded by party agreement, and applies to circumstances that might reasonably give rise to justifiable doubts as to an arbitrator's impartiality.
- Section 67 jurisdictional challenges are streamlined: the court can now remit a successful challenge back to the tribunal, a remedy previously not consistently available across all challenge routes.
- A new section 39A gives tribunals an express statutory summary disposal power — a "no real prospect of success" standard — unless the parties agree otherwise.
- Arbitrator immunity is strengthened: no costs liability for a reasonable resignation, and no costs liability on a removal application unless the arbitrator acted in bad faith.
Important: This article provides general legal information and does not constitute legal advice. Consult a licensed attorney in your jurisdiction for guidance on your specific situation.
Sources
Law Elite Network requires writers to cite primary, official sources — legislation, court decisions, and regulator or institutional publications — for the claims in this guide. Read more about our standards in the editorial process.
Frequently Asked Questions
Does the Arbitration Act 2025 replace the Arbitration Act 1996?
No. It amends the 1996 Act; the underlying statute remains the Arbitration Act 1996, now incorporating the 2025 reforms rather than being superseded by a wholly new framework.
Does section 6A override a contract's separate governing-law clause for the main agreement?
No. Section 6A only concerns the law governing the arbitration agreement itself — a distinct question from the law governing the substance of the underlying contract, which the parties remain free to choose separately.
Can parties still choose a law other than the seat's law to govern their arbitration agreement?
Yes. Section 6A is only a fallback default that applies in the absence of an express choice; an express agreement on the governing law of the arbitration agreement always takes priority over the statutory default.
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