Section 21 of the Arbitration Act Explained: When Do Arbitral Proceedings Commence?

Unless the parties agreed otherwise, arbitral proceedings concerning a particular dispute commence when the respondent receives a request for that dispute to be referred to arbitration. Dispatch alone is not the statutory event. The request, receipt record, disputes identified and appointment clause should therefore be reviewed together.

What Section 21 says

Section 21 of the Arbitration and Conciliation Act, 1996 provides a default rule: unless the parties have agreed otherwise, arbitral proceedings in respect of a particular dispute commence on the date on which a request for that dispute to be referred to arbitration is received by the respondent.

Section 21 commencement is not the same as constitution of the arbitral tribunal. Proceedings may commence for statutory purposes before an arbitrator is appointed, accepts the mandate or receives the statement of claim.

Why receipt matters more than dispatch

The statutory language uses the date on which the request is received. A notice prepared or dispatched within limitation does not by itself establish the Section 21 date if receipt remains unproved or occurred later.

Section 3 contains default rules for receipt of written communications, subject to party agreement. It addresses personal delivery and delivery at the place of business, habitual residence or mailing address, and it also provides a deemed-receipt route where those places cannot be found after reasonable inquiry and the communication is sent to the last known address by a method providing a record of the attempt.

For courier, registered post and electronic communications, preserve the complete service record: booking receipt, tracking report, delivery confirmation, returned envelope, email headers, delivery logs, acknowledgement and the contractually nominated address. Do not assume that a sent-email screenshot alone resolves every receipt dispute.

What must the request communicate?

The communication should do more than demand payment or allege breach. It should make clear that the sender is invoking the arbitration agreement and requests reference of the identified dispute or disputes to arbitration.

A practical invocation request ordinarily identifies:

• the contract and exact arbitration clause;
• the legal names and addresses of the parties;
• the transaction, breach or event that generated the dispute;
• the particular disputes proposed to be referred;
• the principal relief or claim basis, with a provisional amount where appropriate;
• the contractual pre-arbitration steps and their status;
• the appointment procedure, nomination or proposal required by the clause; and
• the method and address used for service.

The notice need not reproduce the eventual statement of claim. It should nevertheless be sufficiently clear to show which dispute is being referred and which arbitration agreement is being placed into motion.

A demand notice is not automatically a Section 21 request

Commercial correspondence may demand payment, reserve rights or threaten legal action without requesting reference to arbitration. Whether a communication qualifies under Section 21 depends on its language, the arbitration clause and the surrounding record.

A safer notice expressly invokes the identified arbitration clause, identifies the disputes and requests their reference to arbitration. Ambiguous expressions such as “appropriate proceedings will be initiated” may create an avoidable dispute about whether arbitration actually commenced.

How Section 21 interacts with limitation

Section 43 applies the Limitation Act, 1963 to arbitration as it applies to court proceedings. Section 43(2) further provides that, for limitation purposes, arbitration is deemed to commence on the date referred to in Section 21.

The Section 21 date therefore helps determine whether a substantive claim was invoked within limitation. It does not revive a claim whose limitation period had already expired before commencement. The underlying cause of action, acknowledgements, part payments, contractual limitation provisions and any legally excludable period still require separate analysis.

In BSNL v. Nortel Networks (India) Pvt. Ltd., the Supreme Court distinguished limitation governing the underlying claims from limitation governing a later Section 11 appointment application. The claim record and appointment-failure record should therefore be charted separately.

Commencement and the Section 11 appointment timeline are different

Section 21 identifies when the arbitration commences under the default statutory rule. Section 11 concerns constitution of the tribunal when the agreed or statutory appointment procedure fails.

For a sole-arbitrator appointment under the default Section 11(5) mechanism, the thirty-day period is linked to receipt of a request to agree on the arbitrator. A contractual appointment procedure may prescribe different steps, authorities or time periods. The same communication can sometimes invoke arbitration and initiate the appointment process, but the clause must be read before assuming that it does both.

Parties may agree on another commencement event

Section 21 begins with “unless otherwise agreed by the parties”. The contract may adopt institutional arbitration rules or specify that proceedings commence upon filing with an institution, payment of a filing fee, service by the institution or another defined event.

The arbitration clause, incorporated rules and later written agreement should therefore be checked before applying the statutory default. A notice drafted without reviewing the agreed regime may use the wrong addressee, filing route or commencement date.

Claims omitted from the notice

Section 21 refers to proceedings “in respect of a particular dispute”. Identifying the dispute is therefore important, but the notice is not necessarily a rigid pleading that permanently fixes every legal ground, calculation or consequential relief.

In State of Goa v. Praveen Enterprises, the Supreme Court explained that claims not mentioned in the invocation notice are not automatically barred from being raised before the tribunal if they fall within the arbitration agreement. The limitation date for a claim raised for the first time later may, however, require a different calculation.

The same decision recognises that a respondent may raise counterclaims falling within the arbitration agreement without having first issued a separate invocation notice, subject to limitation and the contract. It remains prudent to identify known claims and counterclaims early rather than rely on later procedural arguments.

Current Supreme Court position on absence or non-service of notice

The consequences of an absent or incomplete Section 21 notice are fact-sensitive and should not be reduced to one universal formula.

In Adavya Projects Pvt. Ltd. v. Vishal Structurals Pvt. Ltd. (2025), the Supreme Court emphasised the time-related purposes served by Section 21 and described receipt of the invocation notice as fixing commencement. It nevertheless held that non-service of the notice on a person does not by itself prevent that person's later joinder where the person is bound by the arbitration agreement; jurisdiction ultimately derives from consent to arbitrate.

In Bhagheeratha Engineering Ltd. v. State of Kerala (2026), the Supreme Court clarified, on the facts before it, that failure to issue a separate Section 21 notice for additional disputes was not fatal where the disputes were otherwise arbitrable and the parties' conduct had placed the wider controversy before the tribunal. The Court treated Section 21 principally as fixing commencement for limitation rather than as an inflexible jurisdictional bar.

Read together, these decisions do not make careful invocation unnecessary. A clear notice remains the safest method to establish commencement, preserve the limitation record, trigger the appointment procedure and reduce disputes about scope. But absence or non-service is not automatically fatal in every procedural setting; the arbitration agreement, consent, conduct, disputes submitted and prejudice must be examined.

Multiple contracts, parties and disputes

Where a commercial relationship involves several purchase orders, amendments, guarantees, subcontracts or related entities, the notice should map each dispute to the relevant arbitration agreement.

• Check whether all contracts contain the same arbitration clause.
• Identify which entities are signatories and whether any non-signatory theory is relied upon.
• Do not combine disputes governed by inconsistent seats, institutions or appointment procedures without analysis.
• State whether claims arise from one composite transaction or separate legal relationships.
• Serve each intended respondent through the agreed and legally supportable route.

Pre-arbitration negotiation and escalation clauses

Some clauses require negotiation, engineer determination, adjudication, mediation, conciliation or escalation to senior management before arbitration. The invocation record should explain whether the step was completed, waived, exhausted, refused, impossible or rendered futile.

A pre-arbitration step may affect admissibility, appointment timing or the date on which a dispute crystallised. It should not be ignored merely because Section 21 supplies a statutory commencement rule.

How to reply to a Section 21 notice

The receiving party should first preserve the original communication and its receipt date. The reply should then be based on the contract and transaction record rather than a generic denial.

Depending on the facts, the reply may address:

• existence, validity and scope of the arbitration agreement;
• correct parties and authority of the sender;
• seat, venue, institution and governing rules;
• limitation and the alleged cause-of-action dates;
• completion of contractual preconditions;
• claim admissions, denials, set-off and counterclaims;
• the proposed arbitrator or agreed appointment procedure; and
• urgent interim-relief or preservation concerns.

A reply should avoid accidental admissions or waiver of jurisdictional objections. At the same time, non-response can allow the appointment procedure to progress and may later become part of the Section 11 record.

Documents to preserve

• The signed contract and every document containing or incorporating the arbitration clause.
• The complete invocation notice and all annexures.
• Courier, post, hand-delivery and electronic receipt evidence.
• Contractual addresses, change-of-address notices and corporate records.
• Demand notices, replies, acknowledgements, part payments and settlement communications.
• An invoice-wise or claim-wise limitation chart.
• The appointment request, nomination, institutional filing and response.
• Evidence concerning pre-arbitration steps.
• Records supporting urgent Section 9 or later Section 17 relief.
• All communications showing consent, participation, objection or waiver.

Common mistakes

1. Treating dispatch as the statutory commencement date without proving receipt.
2. Sending only a payment demand without requesting reference to arbitration.
3. Invoking the wrong clause, contract, entity or appointment mechanism.
4. Using “all disputes” without identifying the transaction and dispute sufficiently.
5. Assuming Section 21 commencement and Section 11 limitation are the same issue.
6. Ignoring an agreed institutional commencement rule.
7. Relying on repeated reminders to revive a stale claim.
8. Combining multiple contracts without mapping their dispute-resolution provisions.
9. Failing to preserve electronic and physical receipt evidence.
10. Assuming that an imperfect notice is always fatal—or never material—without examining the facts and current case law.

Conclusion

Under the statutory default, arbitration concerning a particular dispute commences when the respondent receives the request to refer that dispute to arbitration. The clause may validly provide a different event, so the contract and incorporated rules come first.

A reliable Section 21 file should establish the dispute, the arbitration agreement, the request, the date and mode of receipt, the limitation position and the appointment step. It should also distinguish commencement of proceedings from constitution of the tribunal and from failure of the appointment procedure under Section 11.

Last updated on: 28/07/2026 at 18:30

Useful internal pages

References / Sources

1. Arbitration and Conciliation Act, 1996 - official India Code PDF.
2. Section 21 - commencement of arbitral proceedings.
3. Section 11 - appointment of arbitrators.
4. Adavya Projects Pvt. Ltd. v. Vishal Structurals Pvt. Ltd., 2025 INSC 507, decided on 17 April 2025.
5. Bhagheeratha Engineering Ltd. v. State of Kerala, 2026 INSC 4, decided on 5 January 2026.
6. State of Goa v. Praveen Enterprises, decided on 4 July 2011.
7. Bharat Sanchar Nigam Ltd. v. Nortel Networks India Pvt. Ltd., decided on 10 March 2021.

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