Aceris Law analysis sets out how English, US, French, and UAE courts treat non-signatory defendants in arbitration — a key tactical question for cross-border claimants

Aceris Law LLC, an international arbitration boutique, has published detailed analysis of a recurring strategic problem in cross-border disputes: whether a claimant can defeat an arbitration clause by joining a non-signatory defendant — that is, a party who never signed the contract containing the arbitration agreement — to court proceedings. The analysis covers four jurisdictions: the United States, England, France, and the United Arab Emirates (UAE). In the US, courts apply several doctrines — including equitable estoppel and implied consent — under which non-signatories can be bound by, or can enforce, an arbitration clause, particularly where the claims against signatory and non-signatory defendants are closely intertwined. In England, the analysis confirms courts' general reluctance to extend arbitration obligations to non-signatories absent a clear doctrinal basis, such as agency, assignment, or novation. The French and UAE positions are also addressed. For English-law practitioners, the non-signatory question arises most acutely in group company structures — where a parent company not party to a subsidiary's contract is joined to litigation — and in joint venture (JV) disputes where affiliated entities are drawn in. The publication of this analysis reflects the growing practical importance of the issue as claimants seek to maximise recovery by widening the defendant pool, and as respondents use arbitration clauses as a shield against multi-party court proceedings.