CII: Cross-Industry Invoice

Cross-Industry Invoice (CII): the UN/CEFACT syntax for e-invoices, alongside UBL the second recognised EN 16931 syntax.

CII (Cross-Industry Invoice) is the XML syntax from UN/CEFACT and, alongside UBL, the second officially recognised syntax for the European standard EN 16931. While UBL is the most widely used syntax on the Peppol network, CII plays an important role in Germany, France and as the basis for the hybrid format Factur-X/ZUGFeRD.

What is CII?

CII was developed by UN/CEFACT (United Nations Centre for Trade Facilitation and Electronic Business) as part of the broader Cross-Industry data model. It describes the same invoice information as UBL but in a different XML structure.

Both syntaxes, UBL and CII, are equivalent implementations of EN 16931. A CII invoice contains exactly the same semantic information as a UBL invoice; only the XML elements and structure are different.

Characteristics
PropertyValueFull nameCross-Industry InvoiceManagerUN/CEFACTEN 16931 syntaxYes (alongside UBL 2.1)Peppol supportYes, via BIS Billing V3Most used inGermany, France
DocumentTypeId

CII BIS Billing V3:

urn:un:unece:uncefact:data:standard:CrossIndustryInvoice:100::CrossIndustryInvoice##urn:cen.eu:en16931:2017#compliant#urn:fdc:peppol.eu:2017:poacc:billing:3.0::D16B
When is CII used?

In practice, you encounter CII mainly in two situations:

As a standalone XML invoice with receivers in Germany and France, where CII is a common syntax alongside UBL. XRechnung, for example, is available in both a UBL and CII variant.

As embedded XML in Factur-X/ZUGFeRD, the hybrid PDF/XML format. The XML contained in a Factur-X file is always CII. This makes CII the dominant invoice format in the French market, where Factur-X is mandatory.

Difference from UBL
AspectUBLCIIStandards bodyOASIS (ISO/IEC 19845)UN/CEFACTPrimary usePeppol network broadlyGermany, France, Factur-XXML namespaceurn:oasis:names:specification:ubl:...urn:un:unece:uncefact:data:...Document typesInvoice, CreditNote (separate)CrossIndustryInvoice (combined)Hybrid formatsNoYes (Factur-X/ZUGFeRD)

An important structural difference: in UBL, invoices and credit notes are separate document types (Invoice and CreditNote). In CII, there is one document type (CrossIndustryInvoice) where the type is determined by a field within the document.

Country-specific CII variants

As with UBL, country-specific CII implementations exist:

VariantDescriptionCII BIS V3Standard Peppol CII invoiceCII NLCIUSDutch implementation in CII syntaxCII XRechnungGerman implementation in CII syntaxFrance CII CIUSFrench implementation (mandatory for PAs)France CII EXTENDED-CTC-FRFrench extended variant with CTC extensions
eConnect and CII

eConnect fully supports CII for both sending and receiving. The PSB automatically transforms between CII and UBL: if you receive a CII invoice while expecting UBL, the platform converts the document. If you send an invoice to a receiver expecting CII, the UBL invoice is automatically transformed.


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