What Is CII XML?
CII XML, or Cross Industry Invoice XML, is a structured data format developed by UN/CEFACT (the United Nations Centre for Trade Facilitation and Electronic Business). It provides a standardized way to represent invoice information in machine-readable XML, enabling automated processing across different systems, industries, and countries.
CII XML is one of the two syntax bindings recognized by the European EN 16931 standard (the other being UBL). In the French e-invoicing context, CII XML serves a dual role:
- Embedded in Factur-X: Every Factur-X document contains a CII XML file attached to a PDF/A-3 container. This XML carries the structured invoice data.
- Standalone format: CII XML can also be used on its own as one of the three accepted formats for the French 2026 reform (alongside Factur-X and UBL).
Structure of a CII XML Invoice
A CII XML document follows the UN/CEFACT D16B schema (or later versions) and is organized around several key data groups:
- ExchangedDocumentContext: Identifies the business process and document type.
- ExchangedDocument: Contains the invoice number, issue date, and document-level notes.
- SupplyChainTradeTransaction: The main body, which includes:
- ApplicableHeaderTradeAgreement: Seller and buyer identification (SIRET, VAT numbers, addresses).
- ApplicableHeaderTradeDelivery: Delivery information.
- ApplicableHeaderTradeSettlement: Payment terms, tax breakdown, totals, and banking details.
- IncludedSupplyChainTradeLineItem: Individual invoice lines with descriptions, quantities, unit prices, and line-level taxes.
This hierarchical structure ensures that all the data needed for automated processing, tax compliance, and accounting integration is present and unambiguous.
CII XML vs. UBL
Both CII XML and UBL are valid syntax bindings for EN 16931, but they differ in several ways:
| Aspect | CII XML | UBL |
|---|---|---|
| Origin | UN/CEFACT | OASIS |
| Usage in France | Core of Factur-X, widely adopted | Less common in France |
| EU adoption | Used in Germany (ZUGFeRD), France | Used in Italy (FatturaPA adapter), Scandinavia |
| Structure | Trade-oriented hierarchy | Document-oriented hierarchy |
| Factur-X compatibility | Native (embedded format) | Not directly compatible |
For French businesses, CII XML is the natural choice because of its integration with Factur-X, which remains the most popular format in France.
Why CII XML Matters for French E-Invoicing
Foundation of Factur-X
Without CII XML, Factur-X does not exist. The XML file is what makes a Factur-X document machine-readable. When accounting software, ERPs, or certified platforms (PDPs) process a Factur-X invoice, they extract data from the CII XML, not from the PDF layer.
Validation and Compliance
The PPF validates incoming invoices against CII XML schema rules. If the XML is malformed, contains invalid data types, or is missing required fields, the invoice will be rejected. This makes generating correct CII XML critical for compliance.
Interoperability
Because CII XML follows an international UN standard, invoices created in France can be understood by systems in Germany (ZUGFeRD uses the same base), and potentially across the EU. This is particularly relevant for businesses with cross-border operations.
CII XML and Factur-X Profiles
The amount of data included in the CII XML varies depending on the Factur-X profile used:
- Minimum: Bare essentials (invoice number, date, totals, seller/buyer IDs).
- Basic: Core fields sufficient for most automated processing.
- EN 16931: Full European standard compliance.
- Extended: Additional fields for complex scenarios (construction, public procurement).
Higher profiles include more XML elements, providing richer data for downstream processing.
Practical Implications
For businesses using billing platforms like Stripe or Recurly, CII XML generation is typically handled by a compliance layer that sits between the billing platform and the French e-invoicing network. The process involves mapping invoice data from the platform’s format into the CII XML structure, validating it against the schema, and either embedding it in a Factur-X PDF or submitting it standalone. Getting the CII XML right is the technical foundation of e-invoicing compliance in France.