Adoption-based nationality (Article 9 CNB) — plenary adoption Hague-aligned

This route concerns the acquisition of Belgian nationality through adoption under Article 9 du Code de la nationalité belge (CNB), a jus filiationis (filiation-based) pathway. Where a child is the subject of a plenary adoption (adoption plénière / full adoption) by a Belgian national, the child acquires Belgian nationality at the moment the adoption takes effect. Only plenary (full) adoption transmits nationality on this basis: the route turns on establishing filiation through that adoption, with nationality flowing as a consequence.

For international adoptions, the pathway requires compliance with the Hague Adoption Convention of 1993. Belgium aligned its adoption framework with the Convention through the Loi du 24 avril 2003, the reform that brought the Hague standards into Belgian law. The Arrêté ministériel du 1er mars 2019 sets out the framework for the recognition of intercountry adoptions. The Cour de cassation (Cass., 1ère ch., 27 mai 2021) confirmed that establishing Article 9 jus filiationis through an international adoption requires verification of Hague Convention compliance.

By contrast, foreign surrogacy arrangements are generally not recognised for nationality-transmission purposes under Belgian Cassation case law; the Article 9 plenary adoption pathway can serve as a supplementary route to establish filiation in such cases.

Belgian nationality is a matter of exclusive federal competence (Constitution, Article 8) and is governed by the Code de la nationalité belge (Loi du 28 juin 1984, M.B. 12 juillet 1984), as subsequently amended. Belgium operates as a trilingual federal state, with the French (Communauté française), Dutch (Vlaamse Gemeenschap) and German-speaking (Deutschsprachige Gemeinschaft) communities, and the applicable procedural language is determined by linguistic-community jurisdiction. Adoption and civil-status matters are administered through the officier de l'état civil at the commune, with the involvement of the Parquet (Procureur du Roi) and the Tribunal de la famille.

Eligibility framework: thresholds calibrated per Code de la nationalité belge (CNB) — Loi du 28 juin 1984 as amended by Loi du 4 décembre 2012 — CNN regime (5-year continuous integration pathway; replaced declaration regime). Language pillar: Dutch OR French OR German per linguistic community (Loi du 18 juillet 1966). Standard floor: 5 years continuous residence (one of three integration pathways under 2012 CNN regime). Region-specific integration: Region-specific integration: Flemish inburgering (VL) / Walloon parcours d'intégration (W) / Brussels primo-arrivants (BXL). EU-loss proportionality where relevant: CJEU Tjebbes C-221/17 + Rottmann C-135/08 — EU proportionality for nationality loss (codified BE 2024).

Standard documentation set for BTH pathway: ID + foreign passport, residence permit (where applicable), region-specific integration certificate (Flemish inburgering / Walloon parcours / Brussels primo-arrivants / DE-Community Dekret), language proficiency certificate (A2/B1 by sub-pathway), tax records (last 3 years), Procureur du Roi clearance. Filing fee EUR 150. See DOFI Vademecum 'Nationalité' 2025 for comprehensive checklists.

Route-specific documentation requirements: statutory anchor under Article 9 CNB; at-birth tracks (Articles 9, 10, 11, 11bis CNB): birth certificate + parental nationality proof; for statelessness preventer Article 10 — both-parent non-transmission attestations + 1954/1961 New York Convention compliance (C.C. 198/2014 procedural safeguards); for Article 11bis post-18 declaration — 5-year residence chain + declaration at municipal civil registrar. Federal Mediator complaint route available (~150 nationality complaints/year); DOFI Vademecum 'Nationalité' provides comprehensive sub-pathway checklists. Filing fee EUR 150 per declaration (Loi 4 décembre 2012 + Royal Decree fee schedule).

Timeline: variable (Article 10 statelessness automatic at birth; Article 11 jus soli automatic at registration; Article 11bis declaration takes 4-6 months). Fee: typically waived for at-birth pathways.

Procedural timeline detail (at-birth tracks): Articles 10 and 11 confer nationality automatically at birth (no application — civil registrar attribution upon birth declaration; deadline 15 days per Code civil Art 56). Article 11bis declaration: file at municipal civil registrar within 5 years of 18th birthday; processing 4-6 months; Procureur du Roi advisory 60-day window applies.

Procedural timeline + costs: declaration filed before the Officier de l'état civil (commune) + Parquet (Procureur du Roi — 4-month opposition window) + Tribunal de la famille. 4-month opposition window from the Parquet (Procureur du Roi). Decision communicated by registered post; absence of opposition = positive acquisition. Standard administrative fee (droit d'enregistrement) per 2024 Code; final inscription in registres de la nationalité. Anchor: Code de la nationalité belge (CNB) — Loi du 28 juin 1984 as amended by Loi du 4 décembre 2012 — CNN regime (5-year continuous integration pathway; replaced declaration regime).

Adoption-based acquisition of Belgian nationality rests on the Code de la nationalité belge (CNB) — the Loi du 28 juin 1984 (M.B. 12 juillet 1984), as subsequently amended.

Core provision.Article 9 CNB is the operative rule for this route: a child adopted by a Belgian national through plenary adoption (full adoption) acquires Belgian nationality at the moment of adoption, on the basis of jus filiationis. This is a transmission of nationality through the established filiation, not a discretionary grant.

Adoption-recognition framework. Where the adoption is international, recognition must comply with the 1993 Hague Adoption Convention, implemented in Belgian law by the Loi du 24 avril 2003 (adoption reform aligning Belgian law with the Hague framework). The Arrêté ministériel du 1 mars 2019 sets out the administrative framework for intercountry adoption recognition. Together these instruments condition Article 9 transmission on verified, validly recognised filiation.

Controlling case law. The Cour de cassation (1ère chambre) in its judgment of 27 mai 2021 (C.20.0445) confirmed that Article 9 jus filiationis through international adoption requires verification of Hague Convention compliance before nationality follows.

Position within the wider CNB scheme

Article 9 sits within the broader structure of the Code de la nationalité belge, which also governs the principal birth-based pathways:

• Article 10 CNB — attribution to prevent statelessness, reflecting Belgium's obligations under the 1961 Convention.
• Article 11 CNB — limited jus soli for the third generation born in Belgium (post-1991 framework).
• Article 11bis CNB — jus soli by parental declaration (post-2012).

The CNB applies uniformly as federal law across the French-, Dutch- and German-language regions. Where an integration condition is engaged for other (residence-based) pathways, the competency-allocation rule of Article 12bis CNB routes applicants to the relevant regional framework (Flemish inburgering, Walloon parcours d'intégration, the Brussels primo-arrivants track, or the German-speaking Community's Dekret); plenary adoption under Article 9, however, transmits nationality directly without an integration requirement.

Constitutional review of the nationality regime has been provided by the Cour Constitutionnelle in, among others, decisions 122/2013, 73/2014, 198/2014, 88/2017 and 132/2020.

Appeal mechanism: Conseil d'Etat admin-chamber review (60-day deadline post-decision); naturalization refusal subject to procedural-deficiency review only - substantive parliamentary discretion (Article 13) NOT directly reviewable. Federal Mediator complaint route (~150 nationality complaints/year). Constitutional Court access for statutory challenges.

Sub-jurisdictional appeal architecture: Conseil d'État (Raad van State / Staatsrat) administrative chamber (60-day filing window post-notification); review limited to procedural-deficiency for parliamentary discretion (Art 13 CNB) but full substantive review for ministerial decisions (Art 12bis). Cour Constitutionnelle (Grondwettelijk Hof) for statutory challenges (Loi 6 jan 1989 framework). Cour de Cassation 1ère chambre for civil-law nationality determinations. Constitutional Court access via C.C. 122/2013 + 73/2014 framework for ancillary residence + integration challenges.

Appeals: refusals/oppositions appealable to the Tribunal de la famille (1ère instance); further appeal to the Cour d'appel and Cour de Cassation per C.C. 73/2014 + 122/2013 + 198/2014 — Cour Constitutionnelle nationality jurisprudence; Conseil d'État + Cour de Cassation apex review. Administrative-grievance pathway via Federal Mediator (Médiateur fédéral) — administrative-grievance anchor; DOFI (Direction Office des Étrangers) Vademecum operational guidance. Substantive merits review under Code de la nationalité belge (CNB) — Loi du 28 juin 1984 as