Peppol directory in Luxembourg: how to register

What is the Peppol directory in Luxembourg?

The Peppol directory in Luxembourg is the register, hosted at directory.peppol.eu, where the identifiers of the companies and institutions affiliated to the Peppol network can be looked up, and in which appearing is not compulsory: a participant stays reachable on the network even where their data is not published there. Joining the network and being published in the directory are therefore two separate steps.

The Peppol identifier is a unique number attached to each entity. The authority compares it to an address in the world of paper mail, or to an email address in the world of electronic mail: it is the coordinate under which a structured document is addressed to its recipient, and nothing more. The directory therefore answers one question only, under which identifier a given entity is reachable, and carries no invoice itself.

That distinction has a concrete consequence for a Luxembourg company invoicing the public sector. The obligation to issue a compliant electronic invoice, set out in our article on public sector e-invoicing obligations, bears on the format and on the transmission channel. It says nothing about the supplier's visibility in the directory, which is a separate and optional step.

Which Peppol identifier does a Luxembourg entity use?

A Luxembourg entity is reachable on Peppol under an identifier made up of scheme 9938, which designates the Luxembourg VAT number, followed by that number. Scheme 9938 applies to every Luxembourg organisation, in the public sector as in the private sector.

A Luxembourg body may also use as its Peppol identifier the identity number of the register of legal persons, the eleven-digit number commonly called the matricule. The codelist does not change for all that: both types of number are written under list 9938, which corresponds to LU:VAT. In other words, the scheme says nothing about the nature of the number that follows it, which catches out the first integrator who meets it.

Two published identifiers make the expected form easy to check. The State Information Technology Centre is reachable under iso6523-actorid-upis::9938:lu10889245, and the Chamber of Commerce under 9938:lu15427942. The prefix iso6523-actorid-upis designates the identification system used; it is the long form of the same identifier, and some software configurations ask for exactly that.

Being connected to the network and appearing in the directory are two different things

Being connected to the Peppol network in Luxembourg and appearing in the Peppol directory are two distinct operations: the first makes the entity reachable, the second makes it findable. It is the responsible access point that publishes, or does not publish, the participant's data in the directory.

The official rule is explicit on both sides. Every member of the network can be found in the directory provided that the responsible access point has published them there, and publishing participant data in that directory is not compulsory. Conversely, all public sector bodies accessing the network through the access point made available by the State Information Technology Centre are published there as a matter of course, and always searchable.

A company that is connected but unpublished remains perfectly reachable by anyone who knows its identifier, and invisible to anyone looking it up. This is a situation we see regularly on engagements: the connection has been subscribed and activated, then supplier invoices keep arriving as PDFs by email, simply because nobody passed the identifier on to trading partners or asked for publication. The budget is committed, the benefit does not follow. The question to put to your provider fits in one sentence: do you publish my identifier in the production directory, and under which number?

How does a Luxembourg company connect to the Peppol network?

A Luxembourg company connects to the Peppol network by renting an access point from a Peppol service provider, or by using invoicing software already linked to the network. The access point of the State Information Technology Centre, for its part, serves public sector bodies.

To guide that choice, the Chamber of Commerce and the Chamber of Skilled Trades have drawn up non-exhaustive lists of invoicing software publishers and of national and international Peppol service providers, published on the authority's e-invoicing website. Accounting software already connected by default avoids a separate integration; failing that, connection goes through renting an access point, which carries variable costs for rental, setup or maintenance.

The public sector route is different and formalised. Every public sector body and every contracting entity must register through a form to state whether it is already able to receive through Peppol, or to request use of the government's Peppol access point and digital mailroom. The Ministry of Digitalisation then adds the body to the published list of public sector organisations, deploys it where applicable in the following days, and informs it once it becomes reachable through Peppol. State ministries and administrations, for their part, must always go through the CTIE access point.

An economic operator that is not yet connected is not blocked for all that. It can transmit its electronic invoices and credit notes through one of the two types of online form available on MyGuichet.lu. That route carries no additional cost, but it offers fewer advantages than automated electronic invoicing: each document is keyed in or uploaded by hand, one at a time.

Which format must an invoice follow to travel over Peppol?

An invoice travelling over the Peppol network in Luxembourg follows the Peppol BIS Billing 3.0 standard, in XML UBL format, the only standard every Peppol access point is obliged to be able to receive and process. The Luxembourg authority strongly recommends using it systematically when sending.

Upstream of that standard sits the European norm. Every electronic invoice must comply with standard EN 16931-1:2017 and with one of the two accepted syntaxes: XML UBL, Universal Business Language, defined by standard ISO/IEC 19845:2015 and maintained by the non-profit body OASIS Open, or XML UN/CEFACT CII, Cross Industry Invoice, drawn up by UN/CEFACT and specified in the 16B XML schemas. Peppol BIS Billing 3.0 is a specialisation of the first syntax, not a competing norm.

The practical consequence is the one we repeat most often: a PDF attached to an email is not an electronic invoice within the meaning of those texts, even if it carries every one of the mandatory details of a Luxembourg invoice. The content is not at fault, the structure is. A Peppol invoice is a machine-readable file in which each piece of data sits in an identified field, and it is that structure the recipient's access point validates before delivering it.

Why register on Peppol before the B2B obligation?

Registering on Peppol in Luxembourg before the B2B obligation avoids running two projects at once: the public procurement obligation has been in force since March 2023, and a bill filed on 30 July 2026 targets transactions between businesses. The May 2022, October 2022 and March 2023 stages covered large, then medium-sized, then small operators in turn.

The legal basis of the public leg has been in place for five years. The law of 13 December 2021, amending the law of 16 May 2019 on electronic invoicing in public procurement and concession contracts, entered into force on 18 December 2021; it requires economic operators to issue only compliant electronic invoices, public sector bodies to use the common delivery network for automated receipt, and State ministries and administrations to go through the CTIE access point. The Grand-Ducal regulation of the same day retains Peppol as the common delivery network, a network managed and maintained by OpenPeppol, an international non-profit association governed by Belgian law.

The business-to-business leg, by contrast, is still only a filed text. Bill 8815, filed on 30 July 2026 by the Minister of Finance Gilles Roth and referred to the Finance Committee, amends the law of 16 May 2019 and the amended law of 12 February 1979 on value added tax, with a view to transposing Article 1 of Directive (EU) 2025/516 of 11 March 2025. No entry into force is asserted here: our article on the B2B e-invoicing bill sets out the state of the parliamentary file.

On the scale the network has already reached, the available source is a secondary one and must be read as such. The Chamber of Commerce reports that the number of invoices transmitted through Peppol in Luxembourg rose from fewer than a hundred in 2021 to close to 1.4 million in 2024, and that around 800 public entities and more than 1,400 private entities already send or receive through the network. Those volumes come from a Chamber of Commerce publication whose date could not be established, and appear on no government source consulted; they give an order of magnitude, not an official statistic.

Sources and verification

Written for Financial Services Luxembourg and reviewed before publication by Mickaël LOC, licensed accountant (authorisation 10077274). The identifiers, formats, connection routes and dates cited here were verified on 18 September 2026 against the official sources listed below.

On the Ministry of Digitalisation's e-invoicing site, efacturation.public.lu: the thematic files section and its frequently asked questions, for the address of the production directory directory.peppol.eu, for the definition of the Peppol identifier compared to a postal address or an email address, for the optional nature of publishing a participant's data in the directory, for the rule that a member is found there provided the responsible access point has published them, for the use of the eleven-digit identity number of the register of legal persons as an identifier, for Peppol BIS Billing 3.0 in XML UBL as the only standard every access point must be able to receive and process, for the required compliance with standard EN 16931-1:2017 and with one of the two syntaxes XML UBL (ISO/IEC 19845:2015, OASIS Open) or XML UN/CEFACT CII (16B schemas), and for the non-exhaustive lists of software publishers and Peppol service providers drawn up by the Chamber of Commerce and the Chamber of Skilled Trades; the public sector section, for the compulsory registration of every public sector body and every contracting entity by form, for the automatic publication in the directory of bodies accessing the network through the CTIE access point, for the government's digital mailroom, for deployment in the following days and notification once the applicant becomes reachable, and for the CTIE identifier iso6523-actorid-upis::9938:lu10889245. On guichet.public.lu: the pages on transmitting an already compliant electronic invoice or credit note and on keying one in manually under a public procurement or concession contract, for the two authorised channels since 18 March 2023, for the two types of MyGuichet.lu online form open to operators that are not connected, for the absence of additional cost on that route and for the variable costs attached to renting, setting up or maintaining an access point. On legilux.public.lu: the Grand-Ducal regulation of 13 December 2021 setting the common delivery network and the alternative technical solutions (Memorial A870), for the designation of Peppol and of the OpenPeppol association, and the law of 13 December 2021 amending the law of 16 May 2019, for its entry into force on 18 December 2021 and for the three obligations it creates. The timetable of the May 2022, October 2022 and March 2023 stages is cited from the e-invoicing file on gouvernement.lu. Parliamentary file 8815 is cited from chd.lu, for the filing of 30 July 2026 and the referral to the Finance Committee. Scheme 9938 as the schemeID of all Luxembourg organisations, public and private, identifier 9938:lu15427942 and the adoption volumes come from the frequently asked questions and from a news publication of the Chamber of Commerce, on cc.lu.

Four limits must be flagged. The primary texts were not read at source: legilux.public.lu and the pages of efacturation.public.lu are unreachable from our drafting environment, and those sources were consulted through indexed extracts; no article numbering of the law of 16 May 2019 or of the Grand-Ducal regulation of 13 December 2021 is therefore cited here. Whether the CTIE access point is open to a private sector entity could not be established: the sources consulted describe the registration form as addressed to public sector bodies and contracting entities, and this article therefore asserts nothing either way. The procedure and time frame for publishing a private participant in the directory are set by no Luxembourg official source consulted: they depend on the access point chosen, which is why the question belongs in the discussion with the provider before contracting. Lastly, the date of the Chamber of Commerce publication carrying the adoption volumes could not be established. Readers can confirm these points on efacturation.public.lu, on guichet.public.lu, on legilux.public.lu, on chd.lu and with the Ministry of Digitalisation's eFacturation helpline, on (+352) 247-72155 or at info@efact.public.lu.

This article states the law as it stands at the date of publication. Formats, identifiers and obligations change, and any decision binding your structure must be checked on the date you rely on it. Report an error to contact@financialservices.lu: the correction is dated in the article.