UN/CEFACT CII — Cross Industry Invoice

EN 16931, the European semantic standard for electronic invoicing, can be written in two XML syntaxes. One is UBL (OASIS); the other is CII (Cross Industry Invoice), maintained by UN/CEFACT. CII is the syntax embedded in Factur-X / ZUGFeRD and the basis of XRechnung.

What is CII?

CII (Cross Industry Invoice) is a UN/CEFACT XML message derived from the SCRDM (Supply Chain Reference Data Model). It is a very rich data model, designed to cover the invoice end to end: header, lines, parties, delivery, settlement, tax. Unlike a proprietary format, CII is an open international standard, expressed in versioned XSD schemas (current version: D16B / 100).

Where EDIFACT INVOIC encodes the invoice as segments, CII encodes it as hierarchical XML. It is the modern XML counterpart chosen by Europe to carry the EN 16931 semantics.

Anatomy of a CrossIndustryInvoice

xml invoice-cii.xml

<?xml version="1.0" encoding="UTF-8"?>
<rsm:CrossIndustryInvoice
    xmlns:rsm="urn:un:unece:uncefact:data:standard:CrossIndustryInvoice:100"
    xmlns:ram="urn:un:unece:uncefact:data:standard:ReusableAggregateBusinessInformationEntity:100"
    xmlns:udt="urn:un:unece:uncefact:data:standard:UnqualifiedDataType:100">

  <rsm:ExchangedDocumentContext>
    <ram:GuidelineSpecifiedDocumentContextParameter>
      <ram:ID>urn:cen.eu:en16931:2017</ram:ID>
    </ram:GuidelineSpecifiedDocumentContextParameter>
  </rsm:ExchangedDocumentContext>

  <rsm:ExchangedDocument>
    <ram:ID>INV-2026-04127</ram:ID>
    <ram:TypeCode>380</ram:TypeCode>
    <ram:IssueDateTime>
      <udt:DateTimeString format="102">20260623</udt:DateTimeString>
    </ram:IssueDateTime>
  </rsm:ExchangedDocument>

  <rsm:SupplyChainTradeTransaction>
    <ram:IncludedSupplyChainTradeLineItem>
      <ram:AssociatedDocumentLineDocument><ram:LineID>1</ram:LineID></ram:AssociatedDocumentLineDocument>
      <ram:SpecifiedTradeProduct><ram:Name>EDI process workshop</ram:Name></ram:SpecifiedTradeProduct>
      <ram:SpecifiedLineTradeDelivery>
        <ram:BilledQuantity unitCode="HUR">2</ram:BilledQuantity>
      </ram:SpecifiedLineTradeDelivery>
    </ram:IncludedSupplyChainTradeLineItem>

    <ram:ApplicableHeaderTradeAgreement>
      <ram:SellerTradeParty><ram:Name>Digital Workshop Ltd</ram:Name></ram:SellerTradeParty>
      <ram:BuyerTradeParty><ram:Name>Solar Cooperative</ram:Name></ram:BuyerTradeParty>
    </ram:ApplicableHeaderTradeAgreement>

    <ram:ApplicableHeaderTradeSettlement>
      <ram:InvoiceCurrencyCode>EUR</ram:InvoiceCurrencyCode>
      <ram:SpecifiedTradeSettlementHeaderMonetarySummation>
        <ram:TaxBasisTotalAmount>1800.00</ram:TaxBasisTotalAmount>
        <ram:TaxTotalAmount currencyID="EUR">360.00</ram:TaxTotalAmount>
        <ram:GrandTotalAmount>2160.00</ram:GrandTotalAmount>
      </ram:SpecifiedTradeSettlementHeaderMonetarySummation>
    </ram:ApplicableHeaderTradeSettlement>
  </rsm:SupplyChainTradeTransaction>
</rsm:CrossIndustryInvoice>

The TypeCode 380 (UNTDID 1001) denotes a commercial invoice; the GuidelineSpecifiedDocumentContextParameter declares the EN 16931 profile the invoice complies with. All the business detail lives under SupplyChainTradeTransaction.

The four blocks of the message

Block	Role
`ExchangedDocumentContext`	Context: profile / guideline (EN 16931, Factur-X…)
`ExchangedDocument`	Header: number, type (380/381…), date
`…TradeLineItem`	Lines: product, quantity, price, line tax
`…HeaderTradeAgreement / Delivery / Settlement`	Parties, delivery, totals and VAT at invoice level

EN 16931: CII and UBL, two syntaxes

EN 16931 does not define a syntax but a semantic model (the information an invoice must carry, the BR-* business rules). The norm is then bound to two syntaxes:

CEN/TS 16931-3-3 — binding to UN/CEFACT CII.
CEN/TS 16931-3-2 — binding to OASIS UBL.

Profiles and data levels

In practice CII comes in profiles (notably via Factur-X / ZUGFeRD), from the lightest to the most complete:

MINIMUM — header data for accounting reconciliation (often not EN 16931-compliant).
BASIC WL (without lines) — no detail lines.
BASIC — minimal EN 16931 invoice with lines.
EN 16931 — fully compliant profile.
EXTENDED — a superset for advanced business needs (beyond EN 16931).

Factur-X, ZUGFeRD, XRechnung

Factur-X / ZUGFeRD: a human-readable PDF/A-3 with an embedded CII XML — this is CII “inside” the PDF.
XRechnung: the German CIUS of EN 16931, realisable in CII or UBL.
2026-2028 reforms: CII (via Factur-X) is one of the target formats of mandatory e-invoicing in France and Germany.

Foundations

Standards

Flagship messages

Tools