Europe's e-invoice formats fall into two groups. UBL, CII, XRechnung, ZUGFeRD, Factur-X and Peppol BIS Billing 3.0 all carry the same EN 16931 semantic model — they differ in syntax (UBL or CII), in packaging (bare XML or hybrid PDF) and in the national rules layered on top. Poland's FA(3) is a separate national schema for the KSeF platform. The buyer's country decides which one you need: XRechnung or ZUGFeRD in Germany, Factur-X, UBL or CII in France, Peppol BIS in Belgium, FA(3) in Poland.
Two syntaxes underneath: UBL and CII
UBL 2.1 and UN/CEFACT Cross Industry Invoice are the two XML syntaxes that the EU lists for EN 16931; every EN-based format on this page is one of them with extra rules.
- UBL 2.1 (Universal Business Language)
- An OASIS standard, also ISO/IEC 19845:2015. Separate document types for
InvoiceandCreditNote. The syntax of Peppol BIS Billing 3.0 and one of the two XRechnung syntaxes. Widely used in the Nordic countries, the Netherlands and Belgium. - UN/CEFACT CII (Cross Industry Invoice)
- A UN/CEFACT XML schema; the EU list references release D16B, and ZUGFeRD 2.5.2 is based on D22B with backward compatibility to D16B. One root element,
CrossIndustryInvoice, for invoices and credit notes alike. The syntax embedded in ZUGFeRD and Factur-X and the second XRechnung syntax.
Both express every EN 16931 business term; a converter can map one to the other without losing core content. The choice usually follows the channel: Peppol means UBL, a hybrid PDF means CII. The model itself is explained on the EN 16931 page.
XRechnung: Germany's specification
XRechnung is a CIUS of EN 16931 maintained by KoSIT, the coordination office for IT standards of the German federal and state governments, originally for invoices to public buyers and now also the reference XML format in German B2B.
Facts: available in UBL 2.1 and CII; adds national rules such as the mandatory buyer reference (the Leitweg-ID for public bodies) and code-list restrictions; comes with a Schematron rule set and a configurable validator; defines an extension mechanism for additional elements. Version 3.0.2 has applied since 1 February 2024 and is kept current through bugfix bundles — the latest is the Winter 2025/26 edition effective 31 January 2026 — without a new major version announced. XRechnung is bare XML: there is no PDF, so the receiver needs software to see it. See XRechnung and the comparison XRechnung vs ZUGFeRD.
ZUGFeRD and Factur-X: the hybrid
ZUGFeRD and Factur-X are one specification with two names — FeRD in Germany and FNFE-MPE in France publish it jointly: a PDF/A-3 file with an embedded CII XML.
The current release is ZUGFeRD 2.5.2 = Factur-X 1.09.2, published on 4 August 2026 and valid from 1 September 2026, fully backward compatible with earlier releases. The profiles decide how much data the XML carries:
| Profile | Content | EN 16931 conformant |
|---|---|---|
| MINIMUM | Header and footer data (aligned with Chorus Pro requirements); no lines | No |
| BASIC WL | Header and footer data without lines ("without lines") | No |
| BASIC | BASIC WL plus essential line data | Yes, as a subset of the core |
| EN 16931 | All elements of the European semantic model | Yes |
| EXTENDED | EN 16931 plus additional elements; in 2.5.2 extended for the French B2B reform and the revised EN 16931 model | Yes, as an extension |
In Germany the BMF names ZUGFeRD and Factur-X as accepted formats, with the rule that the XML takes precedence over the PDF page. In France, Factur-X is one of the three formats every business and every approved platform must be able to receive. Pages: ZUGFeRD, Factur-X.
Peppol BIS Billing 3.0: the network format
Peppol BIS Billing 3.0 is OpenPeppol's CIUS of EN 16931, and the only syntax it requires is UBL 2.1. It is the format that travels over the Peppol four-corner network, and the default format of the Belgian B2B mandate.
Facts: customization ID urn:cen.eu:en16931:2017#compliant#urn:fdc:peppol.eu:2017:poacc:billing:3.0; profile 01 (billing) and profile 02 (billing with response); rules prefixed PEPPOL-EN16931-R on top of the EN 16931 rules, plus country-specific rule sets; current release 3.0.21 (May 2026). Sending on Peppol requires a participant identifier for the buyer, resolved through the SMP/SML directory, and an access point on each side. Germany's federal authorities have accepted Peppol since 27 November 2020, and the BMF lists Peppol BIS among the accepted B2B formats. Pages: Peppol, Peppol identifiers, sending and receiving, Belgium hub.
FA(3): Poland's national schema
FA(3) is the logical structure — an XML schema — for structured invoices issued through Poland's National e-Invoice System (KSeF). It is defined by the Polish Ministry of Finance under the VAT Act and is not a profile of EN 16931.
Facts from the Ministry's brochure: FA(3) applies from 1 February 2026 and replaced FA(2), which was in force from 1 September 2023 to 31 January 2026; correcting invoices that refer to earlier FA(2) or FA(1) documents are also issued in FA(3). The document is organised into Naglowek (header), Podmiot1 (seller), Podmiot2 (buyer), optional Podmiot3 and PodmiotUpowazniony, Fa (the invoice body with lines, amounts and VAT) and an optional Stopka (footer) and Zalacznik (attachment); schema version 1-0E. An FA(3) file becomes a legal invoice only once KSeF has accepted it and assigned its KSeF number; there is no hybrid variant and no Peppol transport. Pages: FA(3), KSeF, Poland hub.
Comparison table
The table lines the formats up by the four questions that matter in practice: which model, which syntax, hybrid or not, and which network.
| Format | Maintainer | Model | Syntax | Hybrid PDF | Network / channel | Country use | Current version |
|---|---|---|---|---|---|---|---|
| UBL 2.1 (EN 16931) | OASIS; binding CEN/TS 16931-3-2 | EN 16931 | UBL | No | Any; Peppol requires it | France (socle), Belgium via Peppol, Germany via XRechnung | UBL 2.1 / ISO/IEC 19845:2015 |
| UN/CEFACT CII (EN 16931) | UN/CEFACT; binding CEN/TS 16931-3-3 | EN 16931 | CII | No (unless wrapped in ZUGFeRD/Factur-X) | Any | France (socle), Germany via XRechnung | D16B (EU list); D22B in ZUGFeRD 2.5.2 |
| XRechnung | KoSIT | EN 16931 CIUS | UBL or CII | No | E-mail, portals (ZRE, OZG-RE), Peppol | Germany B2G and B2B | 3.0.2, Winter 2025/26 bundle |
| ZUGFeRD | FeRD | EN 16931 (BASIC, EN 16931, EXTENDED); sub-core in MINIMUM, BASIC WL | CII | Yes (PDF/A-3) | E-mail, any file transfer | Germany B2B | 2.5.2 (4 August 2026) |
| Factur-X | FNFE-MPE | As ZUGFeRD | CII | Yes (PDF/A-3) | Approved platforms (PA), Chorus Pro for B2G | France B2B and B2G | 1.09.2 (4 August 2026) |
| Peppol BIS Billing 3.0 | OpenPeppol | EN 16931 CIUS | UBL | No | Peppol four-corner network | Belgium B2B default; Germany; many other countries | 3.0.21 (May 2026) |
| FA(3) | Polish Ministry of Finance | National schema (not EN 16931) | Own XML | No | KSeF central platform | Poland B2B (mandatory in phases from 1 February 2026) | FA(3), schema 1-0E |
Choosing the format by buyer country
Let the buyer's country and channel choose; the seller's preference matters only where the law leaves a choice.
- Buyer in Germany. Any EN 16931 format is legal. Public bodies expect XRechnung with a Leitweg-ID. For businesses, ZUGFeRD suits buyers who still want a readable PDF, XRechnung suits automated receivers, Peppol BIS suits buyers reachable on Peppol.
- Buyer in France. From the company's issuing date, the invoice must go through an approved platform in Factur-X, UBL or CII. Factur-X is the natural choice for a supplier who also serves Germany.
- Buyer in Belgium. Peppol BIS Billing 3.0 over Peppol unless both parties agree otherwise.
- Buyer in Poland. FA(3) through KSeF once the seller is within the mandate; the buyer receives it from KSeF, not from you.
- Buyer outside these countries. Peppol BIS is the most widely accepted EN 16931 format across borders; otherwise agree a format with the buyer. See cross-border e-invoicing.
Whether a company's own situation puts it inside a mandate, a threshold or an exclusion requires professional confirmation.
How KRONENWERK handles this
KRONENWERK derives the format from the buyer's country and generates and validates it when the invoice is issued.
| Format | In KRONENWERK | Status |
|---|---|---|
| XRechnung (UBL/CII) | Generated for German buyers; validated with the KoSIT Schematron rules and cross-checked with the Mustang library | SUPPORTED |
| ZUGFeRD | Generated for German buyers as PDF/A-3 with embedded CII; same validation | SUPPORTED |
| Factur-X | Generated for French buyers; transmission through an approved platform is planned via Storecove's approved-platform capability and not yet production-ready — KRONENWERK is not a plateforme agréée | Generation SUPPORTED; transmission NOT YET READY |
| Peppol BIS Billing 3.0 UBL | Generated for Belgian buyers; sent and received over Peppol through an accredited access point provider (Storecove) once the company is connected in Settings → Delivery — KRONENWERK is not itself an access point | SUPPORTED WITH LIMITATIONS |
| FA(3) | Generated for Polish invoices; the KSeF 2.0 module has not been used against the production KSeF, and subscriptions are not currently sold to Polish companies | Generation SUPPORTED WITH LIMITATIONS; transmission NOT YET READY |
| Incoming XRechnung, ZUGFeRD/Factur-X, UBL | Read into bills; the free checker validates a file against a country's rules without storing it | SUPPORTED |
Developers reach the same generation through POST /invoices/drafts on the e-invoicing API; issuing happens in the product after validation. Try a file in the e-invoice checker, or see the product page. Back to the Europe hub.
Frequently asked questions
Is ZUGFeRD the same as Factur-X?
Yes. FeRD and FNFE-MPE publish one technically identical specification; the current release is ZUGFeRD 2.5.2 / Factur-X 1.09.2 of 4 August 2026.
Which is better, UBL or CII?
Neither carries more EN 16931 content than the other. Use UBL where the channel requires it (Peppol) and CII where a hybrid PDF is wanted (ZUGFeRD/Factur-X). XRechnung and the French socle accept both.
Can I send a ZUGFeRD invoice over Peppol?
Peppol BIS Billing requires UBL, so the hybrid PDF is not the Peppol document. The invoice data can be sent as Peppol BIS UBL, with the PDF attached as an additional document if the receiver expects one.
Is FA(3) compatible with EN 16931?
No. FA(3) is Poland's own schema for KSeF. An EN 16931 invoice has to be mapped into FA(3) to be issued through KSeF, and a KSeF invoice has to be mapped out of it for a foreign receiver.
Which XRechnung version is current?
XRechnung 3.0.2, in force since 1 February 2024 and maintained through bugfix bundles; the Winter 2025/26 bundle applies since 31 January 2026.
Sources
- Commission Implementing Decision (EU) 2017/1870 — read on
- European Commission — Obtaining a copy of the European standard on eInvoicing — read on
- KoSIT — XRechnung — read on
- KoSIT — XRechnung versions and bundles — read on
- FeRD — ZUGFeRD 2.5.2 — read on
- FNFE-MPE — Factur-X — read on
- OpenPeppol — Peppol BIS Billing 3.0 — read on
- Ministry of Finance (Poland) — FA(3) information brochure — read on
- European Commission — 2025 Germany eInvoicing Country Sheet — read on
- European Commission — eInvoicing in Belgium — read on
- BMF — Einführung der obligatorischen elektronischen Rechnung (UStAE amendment, 15 October 2025) — read on