Loyalty & Jurisdiction: What does the Paris Ruling of 13 January 2026 tell us?

In this case, the Court sanctioned a party who, after invoking the arbitration clause before a foreign judge, later challenged that same clause to support its annulment application before the French courts. The Court held that the objection to arbitral jurisdiction was inadmissible on the basis of estoppel.

1. The framework

In France, the parties must act with loyalty and consistency before the exequatur or annulment judge. Concretely, they must both raise any irregularity they are aware of before the arbitral tribunal in due time and avoid shifting positions in a way that could mislead the opposing party.

These requirements are enforced through two complementary mechanisms:

• waiver by failure to object (Article 1466 of the French Code of Civil Procedure, applicable to international arbitration via Article 1506, 1°), which deprives a party of the right to rely on an irregularity not timely raised before the tribunal; and
• the estoppel-based inadmissibility, which bars a party from contradicting itself to the detriment of its opponent.

2. Estoppel in brief

Estoppel is a doctrine originating in Common law, imported by French courts on the basis of the general principle that "no one may contradict themselves to another’s detriment" (Cass. Com., 20 Sept. 2011, No. 10‑22.888). It allows courts to declare inadmissible any claim through which a party contradicts its earlier conduct in a way likely to mislead the other side (two cumulative conditions).

3. Concrete examples in matters of arbitral competence

French courts have applied this principle in arbitration in a variety of scenarios. In the context of arbitral jurisdiction specifically, a party that invokes the arbitration clause to secure an advantage cannot later deny its effect.

A party therefore cannot:

• cause the withdrawal of an arbitration request by failing to pay its share of the advance on costs, and later rely on the arbitration clause to oppose the jurisdiction of the state courts (Paris Court of Appeal, 10 Jan. 2019, No. 18/06344; Cass. 1st Civ., 9 Feb. 2022, No. 21‑11.253);
• initiate arbitration proceedings and later challenge the validity of the arbitration clause to contest the tribunal’s jurisdiction (Cass. 2nd Civ., 26 Jan. 1994, No. 92‑12.307; Cass. 1st Civ., 6 July 2005, No. 01‑15.912);
• invoke the arbitration clause before a state court to obtain a stay of proceedings, and then challenge the tribunal’s jurisdiction in the annulment proceedings, even if it reserved its right to dispute the existence of a contractual link – on 13 January 2026, the Court of Appeal held that this reservation had no effect on the possibility of challenging the existence of the arbitration clause (Paris Court of Appeal, 13 Jan. 2026, No. 23/07623).

👉 Your Go‑To Reflex

Before contesting arbitral jurisdiction (or relying on it), anticipate how every procedural position may later be used, challenged, or held against you. In arbitration, every position matters!