CII and UBL side by side: where each invoice field is

In short

UBL and CII both carry the data of the European standard EN 16931, but they organize it differently. A field that sits in one place in a UBL file sits somewhere else in a CII file, under another name. This guide shows where the main fields of an invoice are in each syntax, so you can read an XML file by eye, find a value, or compare a converted invoice with its source.

The numbers in brackets (BT-1, BT-2...) are the identifiers EN 16931 gives to each field. They are the same in both syntaxes, which is what makes a conversion possible.

How to read the paths

UBL invoices have the root element Invoice. Simple values are in cbc: elements and groups in cac: elements. The paths below start inside the root.

CII invoices have the root element rsm:CrossIndustryInvoice, with three blocks: rsm:ExchangedDocumentContext (which specification and process the invoice follows), rsm:ExchangedDocument (number, type, date) and rsm:SupplyChainTradeTransaction (parties, lines, payment, totals). To keep the table readable, four long beginnings are shortened:

• Agreement stands for rsm:SupplyChainTradeTransaction/ram:ApplicableHeaderTradeAgreement
• Settlement stands for rsm:SupplyChainTradeTransaction/ram:ApplicableHeaderTradeSettlement
• Totals stands for Settlement/ram:SpecifiedTradeSettlementHeaderMonetarySummation
• Line stands for rsm:SupplyChainTradeTransaction/ram:IncludedSupplyChainTradeLineItem

The document

The parties

Identifiers carry a scheme that says what they are: in France, a SIREN is the legal identifier with the scheme 0002 (the schemeID attribute in both syntaxes), and a VAT number is marked VA in CII.

The lines

VAT and totals

Payment

Differences that are not about a field

• Dates. UBL writes a date as 2026-01-15. CII writes it as 20260115, with a format="102" attribute that says "year, month, day".
• Currencies. UBL repeats the currencyID attribute on every amount. CII amounts have none, except the total VAT amount: the currency of the invoice is the InvoiceCurrencyCode element.
• Credit notes. In CII a credit note is the same document with the type code 381. In UBL it is another document, with the root CreditNote, a CreditNoteTypeCode and CreditNoteLine elements (with CreditedQuantity).
• Repeated groups. A VAT category appears once per rate in the totals, and on each line. The totals must agree with the lines, in both syntaxes.

Using this when you convert

After a conversion, pick a few fields (the number, the totals, one line, the VAT number) and find them in the source and in the result with this table. The checklist lists what to compare, and the converter does the conversion itself.