UBL, CII, Factur-X: The E-Invoicing Formats You Need to Know in France

The end of PDF invoicing for B2B transactions

 Many businesses still send invoices as PDF attachments to emails. While convenient, this approach will no longer be sufficient under France's e-invoicing reform. For transactions between VAT-registered companies, a new framework is being gradually introduced: from 1 September 2026, all businesses must be able to receive electronic invoices from their large enterprise and mid-sized (ETI) suppliers. The obligation to issue electronic invoices applies from the same date for large enterprises and ETIs, and from 1 September 2027 for SMEs and micro-businesses.

Under this new framework, invoices must go through a certified partner dematerialisation platform (PDP), either directly or via a compatible solution connected to one of them (official list available on the DGFiP website).

The formats recognised by the reform: UBL, CII and Factur-X

The real question is no longer how to send a PDF, but how to choose the right structured data format. To comply with the European standard EN 16931, three formats are accepted under the French reform: UBL, CII and Factur-X.

UBL (Universal Business Language) is a structured XML format widely used across Europe and compatible with the Peppol network for international interoperability. CII (Cross Industry Invoice) is also a structured XML format, designed for automated processing by accounting and financial software. Factur-X, meanwhile, is a hybrid format combining a human-readable PDF with an embedded XML file containing structured data.

Partner platforms are legally required to be able to issue and receive all three formats, and to generate a readable version of each invoice for human verification when needed.

Why structured data changes everything

A standard PDF file, even when sent digitally, does not qualify as an electronic invoice under the reform. To be valid, an invoice must be issued, transmitted and received in structured form, so that it can be processed automatically by IT systems. This structuring brings concrete benefits: better data quality, elimination of manual re-entry, reduced errors and fraud risk, and faster accounting workflows.

A reform that goes beyond simple digitalisation

Beyond the format itself, the reform also introduces obligations around e-invoicing and, in certain cases, e-reporting for transmitting specific data to the tax authorities.

Businesses should therefore start their compliance process now rather than waiting: updating client and supplier databases, checking mandatory invoice fields, selecting the right platform, and adapting internal processes to new business use cases.

It is also worth noting that identifying invoice recipients will no longer rely solely on an email address. The Business Directory, built around SIREN numbers, will be used to locate the invoicing details of your clients. Every business must ensure it can produce, receive and process invoices in UBL, CII and Factur-X formats. This is no longer a feature reserved for large corporations, it is a compliance requirement for all French VAT-registered businesses.

E-invoicing in France

Frequently asked questions e-invoicing in France

Which formats are mandatory for e-invoicing in France?

The reform recognises three core formats: UBL, CII and Factur-X. The first two are purely structured XML formats, while the third is a hybrid format combining a visual PDF with embedded XML data. UBL is also the format adopted for interoperability with the Peppol network.

Is a PDF sent by email still valid?

For now, yes. However, from 1 September 2026, this method will no longer be compliant for transactions with large enterprises and ETIs in France, and from 1 September 2027, it will no longer be valid at all for B2B transactions between French VAT-registered companies. It remains acceptable for B2C customers or international partners.

When does e-invoicing become mandatory in France?

Invoice reception becomes mandatory for all businesses from 1 September 2026. The emission requirement follows the same timeline for large enterprises and ETIs, before extending to SMEs and micro-businesses on 1 September 2027.

Why does the choice of format matter so much?

The format directly determines your regulatory compliance, but also the efficiency of your internal processes, the quality of data exchanged, and your teams' ability to adapt. Choosing the right format makes it easier to integrate invoices into your accounting systems, reduces errors, and ensures a smooth transition to the new legal framework.