Right to file additional claims and counterclaims without independent Section 21 notice

A respondent in arbitral proceedings is legally entitled under Section 23 read with Section 2(9) and Section 23(2A) of the Arbitration and Conciliation Act, 1996 to introduce counterclaims or seek set-offs without being required to issue an independent Section 21 notice of invocation. Similarly, a claimant is permitted to amend, supplement, or introduce new claims before the tribunal pursuant to Section 23(3) without serving a fresh notice under Section 21, provided such disputes fall within the compass of the arbitration agreement. The only legal consequence of raising a claim or counterclaim before the tribunal for the first time without a prior Section 21 notice is that the limitation period for such newly introduced claim will be calculated as on the date of filing the pleading or amendment, rather than the date of the original invocation notice. (M/s Bhagheeratha Engineering Ltd. Vs State of Kerala | 2026 INSC 4)