Divorce and child custody between France and Luxembourg

Brussels II ter often gives several competent courts: the tribunal judiciaire of Metz or Thionville on one side, the Luxembourg district court on the other. The Regulation settles it by lis pendens: the court seised second must decline jurisdiction in favour of the first. The choice is not neutral. Timeframes, cost, the language of proceedings, the French compensatory allowance versus Luxembourg post-divorce maintenance, the way the matrimonial regime is liquidated: everything differs. This analysis comes before any step, including a simple application for interim measures.

Rome III allows the spouses to choose the law of their divorce by written agreement (law of residence, of either spouse's nationality, or of the forum). Failing that, the law of the common habitual residence applies, then that of the last residence if one spouse still lives there and left less than a year ago, then the law of common nationality, then the law of the court seised. The matrimonial regime follows another text, Regulation 2016/1103 for marriages celebrated since 29 January 2019: first common residence after the marriage, unless expressly chosen. A couple married in Metz and settled in Luxembourg may thus fall under the Luxembourg statutory community regime without ever having decided so.

For parental responsibility, residence and contact, jurisdiction lies with the court of the State of the child's habitual residence, assessed concretely: school, doctor, activities, ties. A cross-border move with the children requires the other parent's agreement or the court's authorisation; leaving without agreement exposes the parent to return proceedings under the 1980 Hague Convention, handled within weeks between France and Luxembourg. A decision given in one country is enforceable in the other; if enforcement is blocked, it is sought before the court of the place where the children are.

Jurisdiction and applicable law for maintenance follow Regulation 4/2009 and the 2007 Hague Protocol: the creditor may sue before the court of their own residence, and the law of the creditor's residence applies in principle. Luxembourg salaries, often higher, weigh on the calculation. Maintenance fixed in Metz is enforced in Luxembourg through the central authorities or by direct attachment of the salary paid by the Luxembourg employer; the reverse is true for a debtor employed in France.