Luxembourg Company Registry Data: How to Search the RCS (2026)

The layers of Luxembourg company data

Luxembourg's company data is concentrated in one operator — Luxembourg Business Registers — which runs three distinct registers, plus the financial regulator that supervises the funds and banks the country is famous for. Five sources matter for KYB.

The fifth source is the CSSF — the Commission de Surveillance du Secteur Financier, Luxembourg's financial regulator. The CSSF authorises and supervises the investment funds, fund managers, banks, and investment firms that dominate the Luxembourg economy, and maintains the official public lists of regulated funds and licensed institutions. Because so many RCS entities are funds or fund-related vehicles, the CSSF lists are an essential companion to the registry: the RCS confirms the legal entity exists; the CSSF confirms whether it is an authorised, supervised fund.

Why Luxembourg's data splits open company / closed ownership

Luxembourg deliberately combines broad public access to company records with tight control over ownership data. The key architectural facts for anyone consuming the data:

• One operator, three registers. LBR — an economic-interest grouping of the State, the Chamber of Commerce, and the Chamber of Skilled Trades — runs the RCS, the RBE, and REGINSOL, and since 2025 actively cross-checks them against each other and the national population register.
• Company documents are genuinely free. Unlike many registries that charge per document, Luxembourg publishes articles of association, annual accounts, and resolutions as free PDFs once you hold an account; only certified extracts and official copies carry a fee.
• Ownership is locked down. The RBE exists and is comprehensive, but the 2022 CJEU ruling ended general public access. A commercial user with no legitimate-interest claim cannot pull Luxembourg UBO data — the single most important limitation for KYB here.
• The register is fund-heavy. Because Luxembourg is the second-largest fund domicile globally, the RCS holds an unusually high proportion of holding companies, SICAVs, SIFs, RAIFs, and SPVs. Many of these are layers in cross-border structures, not operating businesses.
• Publication is centralised in RESA. Every change flows through the RESA gazette, giving a single dated, structured feed of register events — the basis for ongoing monitoring.

For multi-jurisdiction KYB, Luxembourg pairs naturally with Germany, Belgium, the Netherlands, and Switzerland — and the recurring challenge is the same: the Luxembourg entity is easy to confirm, but it is often a holding vehicle whose real ownership sits behind the now-restricted RBE and across several borders.

Every Luxembourg company-data dataset, mapped

Across the RCS, RBE, RESA, REGINSOL, and the CSSF, twelve datasets matter for KYB. Luxembourg is open on company data and closed on ownership: most company-level data is free, certified documents are paid, and beneficial ownership is restricted.

Exactly what data is free, paid & restricted

The free tier is broad at the company level. Paid means certified, court-grade documents. Restricted means ownership and supervisory data the law reserves for authorities and qualified parties.

Dataset-by-dataset summary

The same data, viewed by source rather than access tier:

Seven free, two paid, three restricted. Luxembourg's company layer is among the most accessible in Europe — free search, free filed documents, a free gazette, a free insolvency register, and open data. The friction is entirely on the ownership side: the RBE, the matricule, and CSSF supervisory detail are reserved. The 2022 CJEU ruling, not cost, is what stands between a KYB analyst and Luxembourg beneficial ownership. Sources: LBR (RCS, RBE, RESA, REGINSOL), CSSF, STATEC (verified May 2026).

The Luxembourg company identifiers

Luxembourg entities carry a small, clean set of identifiers. The RCS number is canonical; the matricule and VAT number complete the picture, with the LEI for financial-market entities.

For production Luxembourg KYB, the RCS number is canonical and resolves the company record; the EUID links it across EU registries; the matricule matters for identity matching but is not retrievable publicly; the VAT number validates through VIES; and the LEI connects funds and financial entities into global markets data.

Worked example: ArcelorMittal S.A.

To anchor the identifiers and access mechanics in a real record, here is ArcelorMittal S.A. — the global steel group and one of Luxembourg's largest listed companies, a société anonyme registered in the RCS:

Three things the example surfaces. First, the RCS number B82454 — with its B commercial-section prefix — is the stable identifier, and the EUID LURCSL.B82454 is how that same entity is found through the EU interconnection system. Second, ArcelorMittal's articles and annual accounts are downloadable for free, which is more open than many European registers. Third, even for a transparent listed company, the RBE entry — the formal record of who ultimately controls it — is not something a general KYB user can pull from the register; that data now sits behind the legitimate-interest wall.

For contrast, here is the other kind of entity that fills the Luxembourg register — a fund vehicle rather than an operating company:

What the 2025 transparency reform changed

The defining recent development in Luxembourg company data is not a new dataset but a new access regime. Treated as a registry-data question — what's available, and to whom — here is what matters.

Luxembourg created the RBE in March 2019 (under the Law of 13 January 2019), and under the EU's Fifth Anti-Money Laundering Directive the register was open to the general public. That changed on 22 November 2022, when the Court of Justice of the European Union — ruling in a case that arose in Luxembourg itself (WM and Sovim SA v Luxembourg Business Registers) — held that unrestricted public access to beneficial-ownership data violated the privacy rights guaranteed by the EU Charter. Luxembourg suspended public RBE access the same day.

The Law of 23 January 2025, in force from 1 February 2025, rebuilt the framework. It restricts RBE access to national authorities, AML/CFT-regulated professionals, and persons who can demonstrate a legitimate interest (a category that, under the EU's Sixth Anti-Money Laundering Directive, presumes access for journalists and civil-society organisations working on AML). The same law turned LBR into an active gatekeeper: it now runs automated and manual consistency checks on filings, cross-references declarations against the national population register, maintains a live link between the RCS and the RBE, and can request supporting documents. Every natural person registered with the RCS must now provide a Luxembourg national identification number (matricule) — collected for verification and cross-register matching, but not made public. LBR also launched a redesigned public portal in August 2025.

For KYB the practical position in 2026 is clear: Luxembourg company data is open and rich, but Luxembourg ownership data is gated. Confirming who ultimately controls a Luxembourg holding company or fund vehicle now requires either a legitimate-interest claim, an AML-regulated status, or — for most commercial users — building the ownership picture from filed documents, cross-border records, and direct due diligence rather than a single RBE lookup. The EU's wider legitimate-interest rules under the Sixth Directive are due to be further transposed by member states through 2026, so the access boundary remains an active, moving area.

The financial centre behind the register

To read Luxembourg company data well, you have to understand what the register is mostly made of. Unlike a typical national register dominated by local operating businesses, the RCS is disproportionately populated by investment funds, fund managers, and holding and special-purpose vehicles — the legal infrastructure of a global financial centre. The numbers behind that concentration:

The KYB consequence is structural: a Luxembourg counterparty is more likely than in almost any other jurisdiction to be a layer in a cross-border arrangement — a fund, a SOPARFI holding company, or an SPV — rather than a trading business with local substance. That makes the register easy to read at the entity level and ownership the part that demands real work, exactly where the restricted RBE bites hardest.

API and bulk data feeds — the four real paths

For production KYB or fund-due-diligence integrations needing structured Luxembourg company data at scale, four access paths exist. Note that, unlike some registries, Luxembourg does not publish a single free high-volume company-search API — the routes are the portal, open data, EU interconnection, and commercial providers.

Path 1 — The RCS / RESA portal

The LBR portal supports free per-entity search by name or RCS number and free download of filed documents with a registered account. It is the authoritative source for the company record and the RESA gazette, but it is built for human, per-entity lookups rather than high-volume programmatic querying.

Path 2 — Luxembourg open data

Machine-readable company datasets are published on Luxembourg's national open-data portal, data.public.lu, under open licences (Luxembourg strongly favours the CC0 public-domain dedication). This is the route for bulk analytics and building a local mirror of core register data, where datasets are available.

Path 3 — BRIS and the EUID

Luxembourg is connected to the EU Business Registers Interconnection System, and every entity carries an EUID (such as LURCSL.B82454). BRIS provides a standardised cross-border route to confirm a Luxembourg entity from any EU member state's portal — useful for pan-European workflows that span several registers.

Path 4 — commercial multi-jurisdiction APIs and bulk feeds

For teams that need Luxembourg alongside other countries with a consistent schema and real-time access, commercial providers ingest the RCS, RESA, REGINSOL, and the CSSF lists and re-expose them through one API — removing the per-portal friction and adding cross-jurisdiction joins. Zephira's Luxembourg data is sourced directly from these official registers, with Data Provenance attribution on every field, and joined to the UK, Switzerland, Germany, the Netherlands, and 100+ other jurisdictions on a single data model. Bulk delivery via S3 or SFTP is available for batch enrichment and offline analytics. Restricted RBE ownership data is not redistributed to non-authorised parties.

Luxembourg entity types — what each one means for KYB

Luxembourg's entity types include the standard commercial forms plus a distinctive layer of holding and fund vehicles that dominate the register. Six categories account for most KYB-relevant records — and the fund vehicles are what make Luxembourg different.

What the Luxembourg registers don’t tell you

Luxembourg's company data is rich, but for KYB and AML it has real blind spots. Treating the register as the finish line rather than the starting point is the most common mistake on Luxembourg counterparties. The gaps that matter:

• Beneficial ownership is behind a wall. Since the 2022 CJEU ruling, RBE ownership data is not available to general commercial users. You can see the entity and its directors, but not its verified ultimate owners, unless you qualify for access.
• Many ultimate owners aren't in Luxembourg. The CSSF has itself noted that a large share of the UBOs of Luxembourg entities are based abroad, and that complex, layered structures — legitimate or not — make tracing the full ownership chain harder. The Luxembourg entity is frequently one node in a multi-country structure.
• Nominee arrangements are permitted. It is lawful for beneficial owners to use nominee shareholders, so the names visible on a shareholding may not be the people in control — a reason to cross-reference rather than take the register at face value.
• Small companies disclose less. Size-based rules let smaller entities file abridged accounts, so the financial picture for many register entries is deliberately thin (see the thresholds below).
• Struck-off data can persist and age. Records of dissolved entities remain accessible for years after strike-off, which is useful for history but means some visible data may be stale.

Who has to disclose what — the size thresholds

How much financial detail a Luxembourg entity publishes depends on its size class, set by the Law of 19 December 2002 and updated by the Act of 25 October 2024. An entity falls into a class by not exceeding two of three criteria for two consecutive years:

Two practical notes. Sole traders only have to file annual accounts if turnover exceeds €100,000; below that, there is no public financial filing. And the thresholds create a genuine KYB gap — a small entity can legitimately publish very little, so for many counterparties the filed accounts will not reveal much, and verified ownership (the restricted RBE) is the data you actually want. This is precisely where cross-border, multi-source verification earns its place.

Where Zephira sources Luxembourg data from — directly

The most important question for any Luxembourg company-data provider is the source. Zephira goes direct, with source attribution on every record.

Every record carries a Data Provenance panel naming the specific official source and the timestamp of the last refresh. RBE beneficial-ownership data, the national identification number (matricule), and CSSF supervisory detail are not exposed via Zephira to non-authorised parties — those are restricted by Luxembourg and EU law to authorities and qualified professionals.

Recent and upcoming regulatory developments

Six milestones shape the Luxembourg company-data landscape from 2019 through 2026. All dates verified from primary sources.

Luxembourg registry activity — verified primary-source statistics

Two statistical lenses on the Luxembourg company-data landscape: the fund-domicile scale that defines the register, and the insolvency trend that signals counterparty risk.

The fund-domicile scale

Business insolvencies

Luxembourg registry data in regional context

How Luxembourg's access regime compares to other major jurisdictions:

On company data, Luxembourg is one of the most open registries in Europe — free search, free filed accounts, and open data put it ahead of Italy and alongside the UK and Switzerland. On ownership it sits at the restricted end: the UK still publishes beneficial owners, while Luxembourg — the very jurisdiction whose case ended EU public UBO access — now gates the RBE behind legitimate interest. For KYB, that makes the Luxembourg company record easy to obtain and verified ownership the hard part, especially given how many entities are holding and fund vehicles.