New Claims in ICC Arbitration: Where the Cut-Off Sits After the 2026 Rules

1. Can a party add a new claim after an ICC arbitration has started?

Article 25 of the ICC Rules of Arbitration 2026 is short and absolute in its opening words. After the initial case management conference, no party may make new claims unless authorised by the arbitral tribunal. In determining whether to allow such new claims, the tribunal is to consider the nature of the new claims, the stage of the arbitration, any cost implications and any other relevant circumstances.

The structure is therefore a free period followed by a permission regime. What changed on 1 June 2026 is not the existence of the gate but where it stands and how clearly a party can tell that it has passed through it. That distinction is the whole of the practical problem, and it is taken up in the next two sections.

2. Which version of the ICC Rules applies to my arbitration?

This matters more than a transitional provision usually does, because the two editions put the cut-off in different places. An arbitration commenced in, say, March 2026 is running under the 2021 Rules, where the gate is the Terms of Reference. An arbitration commenced in July 2026 under the same arbitration clause is running under the 2026 Rules, where the gate is the initial case management conference. Two disputes under materially identical contracts can therefore face different answers to the same question about a late claim.

The exception in Article 1(2) is also worth reading carefully. It preserves an agreement to submit to the Rules in effect on an earlier date. A clause that simply refers to the ICC Rules of Arbitration, without more, is not such an agreement, and the 2026 Rules will apply to a reference commenced after 1 June 2026. A clause that fixes a particular edition will be given effect. Parties with long-running framework agreements drafted before June 2026 should know which of the two they have.

3. What were the Terms of Reference, and what has replaced them?

Article 23 of the 2021 Rules required the tribunal, after receiving the file, to draw up a document defining its Terms of Reference, on the basis of documents or in the presence of the parties and using their most recent submissions. The document recorded the parties and their representatives, addresses for notification, a summary of the claims and the relief sought, a list of issues to be determined unless the tribunal considered it inappropriate, the arbitrators’ details, the place of arbitration, and the applicable procedural rules. Article 23(2) required it to be signed by the parties and the tribunal and transmitted to the Court within thirty days of the tribunal receiving the file. Article 23(3) dealt with a party that refused to take part or to sign, in which case the Terms of Reference went to the Court for approval. Article 23(4) then provided that after the Terms of Reference had been signed or approved, no party was to make new claims falling outside their limits unless authorised by the tribunal.

The 2026 Rules carry no Terms of Reference article. Article 24 requires the tribunal, within thirty days of receiving the file from the Secretariat, to hold an initial case management conference to consult the parties on the procedural measures that may be adopted under Article 23(2), and during that conference or as soon as possible afterwards to establish the procedural timetable it intends to follow. The Secretary General may extend the thirty day period on a reasoned request from the tribunal or on the Secretary General’s own initiative. The tribunal may hold further conferences and may modify the timetable after consulting the parties.

The substitution removes a step that did real work beyond its procedural function. The Terms of Reference produced an agreed written record, signed by both sides, of what the claims were and what relief was sought. A party that wished to argue later that a claim fell outside the reference could point to a document the other side had signed. Under the 2026 Rules the equivalent record is the procedural timetable and whatever the tribunal minutes of the conference, neither of which the parties sign. Where it matters, and it will matter most in disputes where the scope of claim is itself contested, the cure is to ensure the record of the initial conference states what the claims are with enough precision to be useful twelve months later.

4. What does a tribunal weigh when deciding whether to allow a new claim?

The addition is small on the page and useful in argument. A party resisting a late claim under the 2021 Rules had to bring cost consequences in under the general words. Under the 2026 Rules cost implications are a listed factor in their own right, which means a resisting party can address them directly and a tribunal allowing the claim has to engage with them.

The stage of the arbitration remains the heaviest of the four in practice, and it now bites earlier. Under the 2021 Rules the cut-off arrived once the Terms of Reference were signed or approved, which in a contested case could be some weeks after the file reached the tribunal. Under the 2026 Rules it arrives at the initial conference, which Article 24(1) requires within thirty days of the file reaching the tribunal. A party still formulating its case at that point is formulating it against the clock.

5. How does this compare with the position under Indian law?

The two regimes differ in kind, not only in degree. The ICC Rules fix an event, after which a new claim needs permission. The Act fixes no event and instead gives the tribunal a discretion expressed by reference to a single factor, the delay in making the amendment. A party in an India seated ad hoc arbitration is therefore in a materially better position to bring a late claim than the same party in an ICC reference, and the difference is the product of the rules chosen, not of the seat.

That interaction is the point most often missed when an arbitration clause is drafted. Section 23(3) opens with the words unless otherwise agreed by the parties. An agreement to arbitrate under the ICC Rules is an agreement otherwise, because those Rules fix a cut-off the Act does not. A party that chooses institutional rules is choosing, among other things, to give up the open-ended amendment right the Act would otherwise have given it.

One consequence runs across all three columns. Wherever the cut-off sits, a claim that was never formulated is a claim the tribunal has not been asked to decide, and a tribunal that decides it anyway creates a different and more serious problem at the enforcement stage. The cut-off rules decide when a party may still ask. They do not supply permission that was never sought.

How R & D Law Chambers Works on These Matters

R & D Law Chambers LLP is an Ahmedabad law firm. It advises on arbitration seated in India and abroad, including references under the ICC, SIAC and LCIA rules, the drafting of arbitration clauses, and the conduct of the reference from the request through to the award.

On a question of this kind the first step is usually to establish which edition of the rules governs, because the date the arbitration commenced decides it and the answer changes the analysis. The second is to fix what the claims actually are, early and in writing, since under the 2026 Rules nothing in the process requires the parties to sign a statement of them.

Related services:

• International arbitration: cross-border disputes, enforcement and institutional references
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• ICC, SIAC and LCIA compared
• Drafting the cross-border arbitration clause
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