Skip to main content
Certyneo
Guide · Invoice formats

Factur-X, UBL and CII: electronic invoice formats

The reform requires structured formats, readable by both humans and machines. Three baseline formats are permitted: Factur-X, UBL and CII, all compliant with the European standard EN 16931.

Last updated

The baseline of permitted formats

To ensure interoperability, the reform is based on the European standard EN 16931, which defines a semantic model for invoices. The three baseline formats adopted in France are Factur-X, UBL and CII, all compatible with this standard.

To move from theory to practice, discover the Certyneo electronic signature solution and its offer dedicated to your sector — eIDAS compliant, no installation required.

  • Factur-X is a hybrid format: a readable PDF associated with a structured XML data file.
  • UBL (Universal Business Language) is an XML format widely used internationally.
  • CII (Cross Industry Invoice) is an XML format derived from United Nations work.
  • All three comply with the EN 16931 semantic baseline, ensuring interoperability between platforms.

Understanding the three formats

Factur-X: ideal for transition, it combines the readability of a PDF and the automatic exploitation of an embedded XML.
UBL: pure XML format, valued for integrations with ERPs and cross-border exchanges.
CII: also a pure XML format, based on international standards for commercial document exchange.
EN 16931: the European standard defining mandatory data and their meaning.
Mandatory information: identity of parties, amounts, VAT, legal references.
Archiving: the structured format facilitates invoice storage and control.

How to choose and produce the right format

  1. 1

    Assess your maturity

    Factur-X suits companies in transition; UBL or CII are often required in advanced ERP integrations.

  2. 2

    Check the compatibility of your tools

    Make sure your management software produces one of the standard formats compliant with EN 16931.

  3. 3

    Check mandatory information

    Each format must contain all the tax and legal data expected to be valid.

  4. 4

    Use the platform for conversion

    Your certified platform can convert between formats to ensure interoperability with your partners.

Frequently asked questions

Which format to choose between Factur-X, UBL and CII?
Factur-X is often recommended to start with, as its PDF remains readable while embedding structured data. UBL and CII, pure XML formats, are suitable for advanced integrations with an ERP. All three are accepted by the reform.
Is Factur-X just a simple PDF?
No. Factur-X is a hybrid format: a readable PDF to which a structured data XML file is attached. This structured part is what makes it compliant, unlike a standard PDF sent by email.
What is the EN 16931 standard?
EN 16931 is the European standard that defines the semantic model of an electronic invoice: what data must be included and what it means. Factur-X, UBL and CII all comply with this foundation, which ensures their interoperability.
Do I need to manage multiple formats depending on my clients?
Not necessarily. Your partner dematerialization platform can convert your invoice into the format expected by the recipient. You can therefore produce a single format and let the platform ensure interoperability.
Does my current software produce these formats?
It depends on your tool. Many management software and ERP systems now integrate the generation of Factur-X, UBL or CII. Check with your publisher and test the compliance of the files produced.
→ Electronic signature guide · → Understanding the eIDAS regulation

Related guides and solutions

Explore the related resources from our electronic signature hub.

Structured and secure documents

Certyneo secures your signatures and documents, with hosting in Europe.

Certyneo Community

A question about electronic signatures?

Join the Certyneo community: ask your questions, share your answers and connect with thousands of users and our team.