E-invoice formats: UBL, CII and Factur-X
Answer two questions: the tool suggests the simplest format for you, among the three every platform accepts.
Suggested format
Factur-X
A readable PDF with the CII XML file inside: one document for people and machines.
| UBL EN 16931 | Accepted by every platform |
| CII EN 16931 | Accepted by every platform |
| Factur-X (PDF/A-3 + CII) | Accepted by every platform |
CGI annex IV article 41 septies C (order of 27 July 2026): three base formats.
Prepared by Radif Partners · Method · Tax code, BOFiP and approved-platform list checked on 25 October 2026
Three formats make up the base of French e-invoicing: UBL, CII and Factur-X. The order of 27 July 2026 places them in article 41 septies C of annex IV to the tax code, and every approved platform must be able to receive and process them. All three follow the same European standard, EN 16931, which defines the list of data in an invoice: they say the same thing in different syntax. UBL and CII are pure XML files, designed for software. Factur-X combines a readable PDF with a CII file, for businesses that want to keep a visual document. For a small business invoicing with a word processor or a spreadsheet, Factur-X is often the simplest. For a business with invoicing software or an ERP, the format is usually chosen by the tool itself. A platform may accept other formats from its customers, but it must then convert them.
The three formats side by side
The order of 27 July 2026 refers to three French experimental standards, XP Z12-012, Z12-013 and Z12-014, which set out how the formats are used and the rules specific to France. The table sums up what sets them apart in practice.
| Format | What it is | Human-readable | For whom |
|---|---|---|---|
| Factur-X | PDF/A-3 with embedded CII XML | Yes | Small businesses, invoices read on screen |
| CII | United Nations XML | No | Invoicing software |
| UBL | XML from the OASIS body | No | ERPs, European exchanges |
One standard behind all three
The EN 16931 standard defines the semantic model: which data an invoice must hold, how to name them, which calculation rules to follow. The formats are only ways of writing it. Software can therefore convert UBL into CII without loss, as long as both follow the standard. This is what lets platforms exchange invoices whatever the original format. French rules add checks, for instance on the presence of the customer’s SIREN.
Suggested format
Suggested format
Factur-X
| UBL EN 16931 | Accepted by every platform |
| CII EN 16931 | Accepted by every platform |
| Factur-X (PDF/A-3 + CII) | Accepted by every platform |
How to choose
If your customers want to read their invoices, if you start from a visual template or if you are just starting out, choose Factur-X. If nobody reads your invoices on screen and your software produces XML, CII or UBL are enough. If you use an ERP or EDI, let your vendor and your platform decide: they know the formats your system produces. In every case, the choice is not final, since the platform can convert.
Formats and platforms
The decree of 27 July 2026 gives approved platforms the job of receiving, converting and sending invoices. A platform must accept the base formats, and may also offer others, such as a spreadsheet import or a legacy EDI format. Before choosing, ask which formats it accepts as input and which it can give back, and check that it returns your invoices in a base format if you leave. The page on choosing a platform details these criteria.
For the Factur-X specification as for the French standards, updates appear regularly. Platforms handle them for you; if you produce your files yourself, check the version used at least once a year.