Luxembourg Company Register: How to Search the RCS and Verify Luxembourg Companies (2026)

1. What is the Luxembourg company register?

The register dates to a law of 1909, two older registers merged into one in 1987, and the whole thing was digitised between 2006 and 2007. Since 2003 it has been managed by Luxembourg Business Registers, an economic interest grouping of the Luxembourg State, the Chamber of Commerce, and the Chamber of Trades, under the supervision of the Minister of Justice.

What makes Luxembourg unusual is that LBR runs four registers, not one, wired together. The RCS holds the company file. The RESA is the official gazette, and it is what gives a registered fact legal force against third parties. The RBE is the beneficial owners register, REGINSOL the insolvency register. One search box, four bodies of law behind the tabs.

The RESA point is worth dwelling on. Registered information becomes enforceable against third parties only from the day it is published there, normally within fifteen days. The question is never just whether something is in the register, but whether it has been published yet.

2. How to search the RCS step by step

Searching and reading the company record costs nothing and needs no account. The line between free and paid here is not data versus documents, it is whether you want something the register will certify.

1. Open the LBR site and search

   The homepage search box takes a company name or an RCS number, and the placeholder shows the format. The navigation splits into Immatriculer, Déposer, Consulter, and Commander: registering, filing, consulting, and ordering documents.

   

2. Read the free company record

   You get the registered name, the RCS number, the registered office, the date of registration, and the legal form. For ArcelorMittal that is B82454, 24 Boulevard d'Avranches in Luxembourg, registered on 21 June 2001, société anonyme.

   

3. Try the filings tab, and hit the wall

   The Liste des dépôts tab says plainly that authentication is required. Logging in means a LuxTrust product, a Luxembourg eID card, or an eIDAS certificate at a substantial level of assurance. The documents are free once you are in. Getting in is the obstacle.

4. Use the RESA instead when you cannot log in

   The RESA has its own search module on the LBR site, searchable by registration number or company name, and viewing the publications is free with no login. Anything with legal effect against third parties has been published there, so it is the practical route to a company's history.

5. Order an extract if you need something official

   The Commander route sells extracts and certificates. An electronic extract is EUR 10.43, or EUR 15.43 with a qualified signature. That is what a bank or a counterparty will actually accept.

3. What data is public and what it costs

Luxembourg publishes its fee schedule in full, set by Grand-Ducal regulation rather than by the registry's commercial judgement. Every figure below comes from it and excludes VAT at 17%.

Filing costs money too, and late filing costs more. Registering a société anonyme or a SARL is EUR 105.91, a statutory amendment EUR 54.78, and filing annual accounts on time EUR 19.00. File late and a surcharge lands on top: EUR 50 within the eighth month after the year closes, EUR 200 between the ninth and eleventh, EUR 500 from the twelfth. The same ladder applies to any document filed outside its legal deadline.

That ladder is worth knowing as a reader, not just as a filer. A Luxembourg company whose accounts are eleven months late has paid EUR 200 for the privilege and chosen to do so.

4. Luxembourg legal forms, briefly

Luxembourg has no register divisions. It has instead an unusually long list of registrable forms, because the register that holds ordinary trading companies also holds the fund vehicles the country is known for. Mutual funds, securitisation funds, and reserved alternative investment funds are all registrable entities in their own right.

Branches are registrable too, and a branch of a foreign company costs the same EUR 105.91 as incorporating one. Given how much of Luxembourg's economy runs through foreign groups, branch entries are a meaningful share of the register.

5. How to verify a Luxembourg company: a practical checklist

1. Confirm the RCS number and the registered office

   Search the RCS number and check the name, legal form, registered office, and date of registration against what you were given. All four are free. For a quick first pass, our free company lookup finds the registration and revenue data in one search.

2. Read the RESA publications

   The step most people skip. The RESA is free, needs no login, and holds everything with legal effect against third parties: incorporation, changes of director, capital changes, transfers of registered office, dissolutions. If a fact is not published there, it cannot be held against a third party.

3. Check the domiciliation

   Luxembourg has a large domiciliation industry, and the RESA publishes the end of a domiciliation agreement as its own notice. A registered office shared with hundreds of other entities is normal here, but the end of that arrangement is a signal worth catching.

4. Order an electronic extract before you commit

   EUR 10.43, or EUR 15.43 with a qualified signature. This is what a counterparty or a bank will accept, and it carries the current legal representatives.

5. Look for the accounts, and know when not to expect them

   Accounts are filed to the RCS, but a defined list is not viewable by the public: SNCs and SCSs whose unlimited partners are not themselves limited companies, economic interest groupings, and Luxembourg branches of foreign companies. Absent accounts often mean the form, not a failure to file.

6. Check REGINSOL

   The insolvency register publishes monthly statements of court rulings and administrative dissolutions, naming the entity and its number. You can also request a certificate confirming no such decision is registered.

6. Limitations of the official register

To be clear: Luxembourg's register is well run, well documented, and honestly priced. The limits are specific and sharp:

• Filings sit behind a Luxembourg identity. Viewing filed documents is free, but only after authenticating with a LuxTrust product, a Luxembourg eID card, or an eIDAS certificate at a substantial assurance level. A foreign company doing occasional checks has none of those.
• Some accounts are never public. Legislation sets out what the public may see. Annual accounts of certain partnerships, of economic interest groupings, of pension savings vehicles, and of Luxembourg branches of foreign companies are not viewable, and small companies may withhold the profit and loss account, the management report, and the auditor's report.
• Beneficial ownership is closed. The RBE has been shut to the public since November 2022, so the register cannot answer who ultimately owns a Luxembourg entity.
• The API costs EUR 5,000 a year. There is a real official platform, with a published price, and that price is a flat annual fee rather than a per-call rate. For a few thousand lookups a year it is poor value.
• No firmographics. Revenue as a field, employee counts, industry codes, and contact details are not register data. The accounts exist as filed documents, where they are public at all.
• Publication lag. A registered fact is only enforceable against third parties once it appears in the RESA, normally within fifteen days, so the register and the gazette can disagree for a fortnight.
• Fund vehicles complicate matching. One register holds trading companies, holding companies, partnerships with no legal personality, and funds, all with RCS numbers that look alike.

If you check one Luxembourg entity a quarter, none of this matters. If you onboard hundreds, it is the whole problem.

7. Access RCS data programmatically

CompanyData maintains a normalized database of all 166,274 Luxembourg entities, sourced directly from the RCS and the RESA and refreshed as new filings appear. RCS numbers are parsed and validated, RESA publications are matched back onto the company they concern, filed accounts are read into structured fields where they are public, and records are enriched with revenue, employees, industry codes, and contact data the register does not hold.

Our Company Data API lets you look up any Luxembourg entity by RCS number, name, or address and get structured JSON back in real time, with 150 free lookups to start, no LuxTrust certificate, and no EUR 5,000 annual platform fee. It is used by developers, banks, and insurers across 190+ countries, so Luxembourg checks work exactly like checks anywhere else.

GET /v1/companies?country=LU&registration_id=B82454

{
  "name": "ArcelorMittal",
  "legal_form": "Societe anonyme",
  "registration_id": "B82454",
  "address": "24, Boulevard d'Avranches",
  "postcode": "1160",
  "city": "Luxembourg",
  "registration_date": "2001-06-21"
}

Every field above is what the free record on the LBR site shows. The filings, the RESA publications, and the financial figures come back on the same record, without the authentication step the portal puts in front of them.

8. Luxembourg vs other company registers

Luxembourg is transparent about its rules and restrictive about its data. For context: