Luxembourg (LU)

The 13-digit national identification number — the most important personal identifier in Luxembourg. Format: YYYYMMDDXXXXX (date of birth + sequence). Used for all government services, social security (SECU), tax (ACD), healthcare (CNS), banking, and official transactions. Assigned automatically when you register at your commune or when born in Luxembourg. Without this number, you cannot function in Luxembourg's administrative system.

Essential for all immigration and official registrations. Non-EU nationals must hold a valid passport throughout their stay. EU nationals may use their national identity card for most purposes within Luxembourg and the EU.

EU/EEA citizens staying more than 3 months must register at their commune (municipality) and obtain a Certificat d'enregistrement (registration certificate proving right of residence). This is the most fundamental document for EU expats in Luxembourg. Obtained at the commune administration within 8 days of establishing residence.

Non-EU nationals require a titre de séjour (residence permit) to live and work in Luxembourg beyond 90 days. Different types: salarié (employed), travailleur hautement qualifié (highly qualified worker/EU Blue Card), travailleur indépendant (self-employed), regroupement familial (family reunification), étudiant (student). Applied for at the Direction de l'Immigration (guichet.lu).

Proof of registration at your commune (municipality). Must be done within 8 days of establishing residence at a new address. This document proves your address and is required for many official processes including bank account opening, CNS registration, and SECU enrollment. Obtained at the commune administration (administration communale) of your municipality.

LuxTrust is Luxembourg's national digital authentication system, equivalent to Danish MitID or Belgian itsme. Required to access all Luxembourg e-government services via MyGuichet.lu: tax returns, social security, residence registration, and more. You need a numéro national to activate LuxTrust. Available as a signing stick (LuxTrust Stick), a mobile app, or a smart card.

Your Caisse Nationale de Santé (CNS) health insurance membership card. Issued automatically after SECU registration. Present at every medical appointment, pharmacy, and hospital. Contains your numéro national and confirms your CNS membership. Without this, you pay full medical costs upfront (with reimbursement possible but complex).

Annual income tax return filed with the ACD (Administration des Contributions Directes). Most employed residents do not need to file if in the correct tax class. However, those with multiple income sources, investment income, self-employment, or non-standard deductions must file. Critical to declare your tax class correctly — wrong class leads to massive over or under-payment.

Required for registering children, family reunification applications, citizenship applications, marriage registration, and some benefit claims. Must be an official certified copy from your country of birth.

Required for family reunification, tax class 2 declaration, benefit applications, and inheritance matters. PACS (Partenariat civil / Partenariat enregistré) is legally recognised in Luxembourg and entitles partners to tax class 2 status.

Required for commune registration and for most administrative procedures. A signed rental contract (bail) or written attestation from a property owner. Required to be registered at your actual residential address — not an office or friend's address.

Required for recognition of foreign professional qualifications, some residence permit types and access to regulated professions. Academic recognition is processed by the DQRD (Direction de la Qualification et Reconnaissance des Diplômes) under the Ministry of Higher Education. Regulated professions have separate boards: Ordre des médecins for medicine; Barreau du Luxembourg for law; Ordre des architectes et ingénieurs-conseils for architecture/engineering. Luxembourg is a Hague Apostille member; apostille and certified translation required for non-French/German/Luxembourgish originals.

EU licences are valid in Luxembourg and recognised across the EU. Non-EU licences must be exchanged for a Luxembourg licence within 12 months of establishing residency. Exchange process via the SNCA (Service National de la Circulation Automobile). International driving permits may be required for some non-EU licences during the exchange period.