Formats of Electronic Invoice 2026 — Factur-X, UBL and CII — What Difference?
Three electronic invoice formats are authorized in France in 2026: Factur-X, UBL 2.1, and CII. Understanding their differences allows you to choose the right format according to your business and to properly configure your software.
Understanding billing
What is a structured electronic invoice?
A compliant electronic invoice is not a PDF sent by email. It is a document containing structured XML data, automatically readable by computer systems without any human intervention.
Type | Format | Automatic processing? | Compliant 2026? |
Standard PDF (email) | Digital image, human-readable only | No | No |
Factur-X | PDF + embedded XML — readable by both human AND machine | Yes | Yes |
UBL 2.1 | Pure XML — structured data only | Yes | Yes |
CII | Pure XML — structured data only | Yes | Yes |
The format for your SME
Factur-X — The recommended format for French SMEs
Factur-X is a hybrid format: a human-readable PDF with an embedded XML file inside. The human sees a classic and familiar PDF. The computer system reads the structured XML. It is the ideal solution for SMEs that want compliance without disrupting their work habits.
- Your teams always see a readable and printable PDF — no disruption of habits
- Automatic processing is possible on the client side without any changes on their part
- Compatible with all certified French PDPs
- Natively generated without development by Odoo 16+, Sage 100, Cegid, Pennylane
- In accordance with the European standard EN 16931 — guarantees international interoperability
Factur-X Profile | Usage | Recommended? |
MINIMUM | Very simple, internal use — minimal data only | Insufficient for 2026 |
BASIC WL | Standard without item detail lines | Limited use |
BASIC | Standard with item detail lines | Acceptable |
EN 16931 | Target profile — all mandatory and recommended data | Recommended for SMEs |
EXTENDED | Large enterprises, specific sectors | If required by client |
The format for international
UBL 2.1 — For international exchanges
Universal Business Language 2.1 is a pure XML format primarily used for international exchanges and European public procurement. Unlike Factur-X, it does not contain a human-readable PDF version.
When UBL is relevant for your SME:
- Exchanges with European partners via the Peppol network (BIS Billing 3.0)
- Public procurement — Chorus Pro B2G for invoices to public authorities
- Foreign clients or suppliers who specifically require UBL
- Export to countries where UBL is the national standard: Netherlands, Scandinavia, Belgium
For French SMEs in domestic B2B, Factur-X is largely sufficient. UBL becomes necessary only if you have significant international activity or public contracts.
Large enterprises & industry
CII — For large enterprises and industry
Cross Industry Invoice is a pure XML format derived from ISO standards. It is mainly used by large companies and existing industrial EDI exchanges. For French SMEs, CII is generally not necessary — Factur-X covers all standard use cases.
Typical use cases of CII: large industrial groups with existing EDI flows (automotive, aerospace), exchanges with partners who are already using CII in their IS.
Let's compare the different formats
Comparison table of the 3 authorized formats
Criterion | Factur-X | UBL 2.1 | CII |
Human readability | Yes — integrated PDF | No — pure XML | No — pure XML |
Automatic processing | Yes | Yes | Yes |
Main use | SME France B2B | International / Peppol | Large enterprise / EDI |
Standard | EN 16931 (EU) | EN 16931 (EU) | ISO 19005 |
Supported by Odoo | Yes — native | Yes — native | Yes — native |
Recommended for SME France | Yes | As needed | Rarely |
Compatible with all PDP FR | Yes | Yes | Yes |
Configuration
How to configure formats in Odoo
Factur-X
Accounting → Configuration → Journals → Customer invoices → Advanced settings → Electronic invoicing section → Enable Factur-X (FR) → Profile: EN 16931
UBL
Same path → Enable UBL 2.1
Once activated, when an invoice is sent, Odoo automatically generates the file in the selected format. The Factur-X file is attached to the sent PDF or transmitted directly via the configured PDP.
Are you ready for 2026?
We offer an appointment to assess your level of preparation.
FAQ
FAQ - Formats of electronic invoices
Technically yes — a Factur-X file is a PDF with embedded XML, which you can send by email. But for legal compliance in 2026, the transmission must go through a certified PDP, not by regular email. Email can be used for informal confirmation copies, but not for the official transmission that creates the tax obligation.
No, not at all. Certified PDPs ensure automatic conversion between formats. You issue in Factur-X, and your PDP converts if necessary for your client's PDP that uses UBL. Interoperability between formats and PDPs is a regulatory requirement imposed by the DGFIP in the certification specifications.
Yes, starting from Odoo 16 with the French localization (l10n_fr) installed. The Factur-X EN 16931 format is generated natively. No additional module is needed for format generation — modules may be useful for certain advanced configurations like connecting to specific PDPs.
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