Factur-X, UBL, CII: Which E-Invoice Format Should You Choose?

Quick answer. From 1 September 2026, all VAT-registered businesses in France must receive electronic invoices. Three formats from the European minimum standard (EN 16931) are recognized: Factur-X (hybrid PDF/A-3 readable + embedded XML CII), UBL (pure OASIS XML) and CII (pure UN/CEFACT XML). Your choice depends on your clients, software and interoperability needs. Approved platforms automatically convert between formats, so choosing one is enough to be compliant.

Directive 2014/55/UE imposes a common semantic standard across all EU Member States: EN 16931. Adopted in 2017 by the CEN (European Committee for Standardization), this standard defines mandatory invoice data (number, date, amounts, VAT, party identification, etc.) and validation rules. However, the Directive leaves each Member State free to implement this semantics according to local legal requirements.

France recognizes three syntaxes compliant with EN 16931: Factur-X, UBL and CII. In other words, EN 16931 specifies what to include in an invoice; the three formats specify how to write it in XML (or PDF+XML for Factur-X). This plurality reflects pragmatic reality: large enterprises and mid-caps, often embedded in European ecosystems (PEPPOL, B2B networks), favour UBL; SMEs and traditional sectors find the hybrid Factur-X format with readable PDF more accessible; complex or international supply chains exploit CII's expressiveness (UN/CEFACT).

At Hayot Expertise, we advise clients that the choice is not about tax compliance: all three are recognized by France's tax authority (DGFiP). It depends on your suppliers, your accounting software and your B2B flows.

1. Factur-X: The Franco-German Hybrid Format#

Factur-X is a mixed format combining two layers in a single file:

• Readable PDF/A-3 layer: a PDF document conforming to archival standards (PDF/A-3 ISO 19005-3). An accountant or auditor can open it with any PDF reader and view the invoice like paper. Mandatory information (number, date, vendor SIREN, net and gross totals, VAT breakdown by rate) is visually legible on screen.

• Embedded CII XML: within the same PDF file, an XML stream (based on UN/CEFACT Cross Industry Invoice D22B standard) is attached. This is structured data that accounting software and approved platforms extract automatically to import invoices without re-keying.

Main advantage: human and machine readability in a single object. Useful when your client wants visual proof (audit, physical archiving, PDF signature) while benefiting from automation.

Factur-X profiles: the format defines five levels of data richness (MINIMUM, BASIC WL, BASIC, EN 16931, EXTENDED), from leanest (just identification + amounts) to richest (logistics, multi-party payments, sector extensions). For 2026 compliance, the EN 16931 profile ("Comfort") covers the complete European semantic standard; EXTENDED adds fields for supply chain.

Technically: Factur-X is the French version of Germany's ZUGFeRD 2.4 standard (from January 2026). They are interchangeable.

2. UBL: Pure XML for PEPPOL Interoperability#

UBL (Universal Business Language) is a purely XML format maintained by OASIS. No PDF, no readable layer: it is raw data structure.

Simplified example (pseudocode):

<Invoice>
  <ID>INV-2026-001</ID>
  <IssueDate>2026-06-06</IssueDate>
  <AccountingSupplierParty>
    <PartyIdentification>
      <ID schemeID="VAT">FR12345678901</ID>
    </PartyIdentification>
  </AccountingSupplierParty>
  <InvoiceLines>
    <InvoiceLine>
      <Item><Description>Service...</Description></Item>
      <LineExtensionAmount>1000.00</LineExtensionAmount>
    </InvoiceLine>
  </InvoiceLines>
  <TaxTotal><TaxAmount>200.00</TaxAmount></TaxTotal>
  <LegalMonetaryTotal><PayableAmount>1200.00</PayableAmount></LegalMonetaryTotal>
</Invoice>

Main advantage: UBL is the preferred format for European B2B exchange networks (PEPPOL, openPEPPOL). If your clients or suppliers operate on an EDM (Electronic Document Management) or public PEPPOL platform, UBL is the natural choice. Slightly simpler than CII in structure.

Limitation: no readable layer. If the email exits the EDI circuit and lands in Outlook, the recipient sees raw XML code. Less user-friendly for small structures without software integration.

3. CII: Rich Pure XML for Complex Exchanges#

CII (Cross Industry Invoice) is a purely XML format maintained by UN/CEFACT (the UN body for electronic commerce). Richer and more complex than UBL, it is designed for highly structured invoices, multi-currency payments, international exports and complex supply chain scenarios.

Main advantage: expressive richness. If you need to describe multiple currencies, multiple payment entities, shipment batches, HS tariff codes, granular logistics details, CII offers fields that UBL does not provide. Common in pharmaceutical, automotive and international trading sectors.

Limitation: more complex to implement. Requires XML expertise and mastery of UN/CEFACT semantics. Less popular in France than Factur-X or UBL among SMEs.

You are an SME, micro-business or freelancer#

Recommendation: Factur-X.

Your accounting software (Cegid, Pennylane, Sage, etc.) almost universally supports Factur-X with integrated PDF generation. Your clients—other SMEs, traders, professional firms—appreciate being able to download and read the invoice as PDF, even though it is also structured in XML for automatic processing. No complex EDI integration required. Your service providers (accountants, auditors) are familiar with Factur-X. Compliance cost and timeline are minimal.

You are a mid-cap, large enterprise or B2B operator#

Recommendation: UBL or CII depending on your ecosystem.

• If you exchange via PEPPOL (public networks, tenders, public procurement) → UBL.
• If you have complex supply chain flows, multi-currency, international → CII.
• If uncertain → UBL (more common, simpler than CII).

Your EDI and document management systems are already integrated and do not depend on a readable PDF layer.

You mix B2B and B2C (e-commerce, multi-channel distribution)#

Recommendation: Factur-X by default, then UBL if specific clients request it.

Issue in Factur-X (hybrid, client-friendly). Approved platforms automatically convert to UBL or CII for those who request it. You manage one format on your end; the platform handles translation.

A critical point: you do not need to choose a "universal" format. Here is why.

From 1 September 2026, every electronic invoice must pass through an approved platform (PDP — Plateforme de Dématérialisation Partenaire). It performs four key functions:

1. Issue/receive: it collects your invoice, validates it, transmits it to the client and authorities.
2. Format conversion: it automatically converts between Factur-X, UBL and CII. You issue in Factur-X; it delivers to a UBL or CII client without your intervention.
3. Transmission to DGFiP: it extracts tax data (identifiers, amounts, VAT) and sends it to France's tax authority for audit.
4. Signature and timestamp: it ensures authenticity and integrity (eIDAS, qualified).

Practical consequence: you can issue exclusively in Factur-X. Your client expecting UBL receives a UBL conversion; one preferring CII receives a CII conversion. The platform handles translation thanks to the common semantic foundation (EN 16931).

This also means that the question "which format?" is less critical than "which software/tool generates the format?" You must verify that your accounting software, ERP or invoicing solution can generate at least one of the three formats. Then you tell your approved platform: "My invoices arrive in Factur-X". It handles the rest.

Factur-X (and UBL/CII) support profiles or levels of data richness aligned with EN 16931.

For France, the AFNOR XP Z12-012 standard (February 2026) defines:

To these profiles are added France extensions (EXT-FR-FE) covering French tax specifics: reverse-charge indicators, intra-EU trade declarations, reduced VAT regimes, etc.

At Hayot Expertise, we recommend issuing at minimum in EN 16931 profile (certain compliance) and enriching to EXTENDED if your sector or clients require it (e.g. export or complex supply chain).

Hospitality & Restaurants#

Factur-X with HCR extensions to manage cash handling, services, beverages and payment terminal invoicing. The approved platform will convert to UBL for suppliers requesting it.

Construction & Building#

Factur-X or CII depending on complexity. Situation invoices, progress payments, retention sums and multiple lots push toward EXTENDED or CII for richness. Factur-X suffices for a straightforward company.

E-commerce & Wholesale#

Factur-X. Automatic conversion to UBL if PEPPOL networks are involved (tenders, structured distribution chains).

Import/Export#

CII if you need to describe multi-currency, HS codes, customs calculations; UBL otherwise. Factur-X remains possible but less expressive for tariff complexity.

1. No infinite postponement: 1 September 2026 arrives soon. Test your software now. Do not assume "it will work in time"—software adjustments take time.

2. Format conversion costs CPU: although approved platforms convert automatically, each conversion (Factur-X → UBL → CII) introduces a microscopic delay. For very high-volume flows (thousands of invoices daily), issuing in your clients'/suppliers' native format minimizes bottlenecks.

3. Digital signature and archiving: Factur-X hybrid allows signature on the readable PDF; UBL/CII require XML tag signature. Clarify your archiving needs with legal counsel.

4. Schema validation and profiles: Factur-X, UBL and CII files must validate against the correct schema (schematron, XSD). A Factur-X claiming EN 16931 but missing VAT will fail validation. Ensure your software emits a profile consistent with its declaration.

5. PPF is not your platform: the Portail Public de Facturation (PPF) is only a directory and data concentrator. You do not deposit invoices directly at the PPF. You choose an approved platform (for example Pennylane, Cegid, Yooz or another registered vendor) that connects to the PPF.

Recently, a distribution SME consulted us: it wanted to issue hybrid Factur-X invoices to small clients (traders, craftspeople) but feared that large retailers (its key buyers) would demand UBL. We verified with its three largest clients: none required a specific format. They all had an approved platform in place accepting Factur-X. Result: this SME adopted Factur-X, minimal cost, compliance guaranteed from September 2026.

This scenario repeats often. Factur-X poses no problem unless your ecosystem operates on closed EDI (legacy proprietary EDIFACT standards) without an approved platform. But the legal framework mandates the platform. So, Factur-X is in practice the most pragmatic choice.

That said, a listed mid-cap or large import-export firm may find advantage in UBL (PEPPOL) or CII (logistics complexity). It is a legitimate and technically sound choice. But SMEs asking "which format will save us?" get the same answer: Factur-X, because it is readable, universally supported, and platforms convert it where needed.

Hayot Expertise Advice. Before debating format, ask yourself three questions: (1) Does my accounting software support at least one of the three formats? (2) Do my key clients/suppliers mandate a format? (3) Are my flows simple (typical SME) or complex (supply chain, multi-currency, export)? The answers dictate the choice. Next, sign a service contract with a recognized approved platform from the official list and let it pilot compliance. Your role is limited to validating that your issued invoices are well-formed and in EN 16931 profile minimum. We guide you through these steps.