Compare · UBL vs CII
UBL vs CII: Which XML Syntax Should You Use?
UBL (Universal Business Language) and CII (Cross-Industry Invoice) are two XML syntaxes for expressing EN 16931 invoices. Both carry the same business information—the difference is technical structure. Your choice usually depends on which formats and networks you need to support.
TL;DR
UBL 2.1 (OASIS): verbose, self-documenting element names, required for Peppol BIS. CII (UN/CEFACT): compact element names with deeper nesting, required for ZUGFeRD/Factur-X. Both serialize the same EN 16931 semantic model — the choice is driven by your target network and format, not data capability.
| Feature | UBL | CII |
|---|---|---|
| Full Name | Universal Business Language 2.1 | UN/CEFACT Cross-Industry Invoice |
| Maintained By | OASIS | UN/CEFACT |
| Used By | Peppol, XRechnung | ZUGFeRD, Factur-X, XRechnung |
| File Size | Typically larger | Typically smaller |
| Structure | More verbose/explicit | More compact |
| International Adoption | Higher (Peppol network) | Strong in EU (Franco-German) |
UBL 2.1 (OASIS) uses explicit, self-documenting XML element names. It is the required syntax for Peppol BIS Billing 3.0 and one of the two accepted syntaxes for XRechnung. Dominant in international e-invoicing and government procurement.
UN/CEFACT CII uses compact element names with deeper nesting, producing smaller files. It is the required syntax for ZUGFeRD and Factur-X, and the second accepted syntax for XRechnung. Dominant in Franco-German trade corridors.
Structure and Verbosity
UBL uses explicit, self-documenting element names. More verbose but easier to read without documentation.
CII uses shorter element names with more nesting. Smaller files but requires documentation reference.
Ecosystem
UBL dominates international trade (Peppol connects 40+ countries). If you need to invoice globally, UBL is more widely supported.
CII is strong in France and Germany. If most of your trade is Franco-German, CII tools are abundant.
UBL
- Connecting to Peppol network (required)
- Invoicing internationally
- Working with UK, Nordic, Belgian businesses
- Your ERP exports UBL natively
CII
- Creating ZUGFeRD or Factur-X invoices (required)
- Trading primarily France/Germany
- Want smaller file sizes
- Your ERP exports CII natively
Check if your UBL or CII invoice is correctly structured.
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Frequently Asked Questions
- Which is more widely supported?
- UBL has broader international support via Peppol. CII is dominant in Franco-German trade. Both are fully supported for EN 16931 compliance.
- Can I convert between UBL and CII?
- Yes, both map to the same EN 16931 semantic model. Conversion tools exist, and many platforms handle it automatically.
- Does it matter for German government?
- No—XRechnung accepts both UBL and CII. Choose based on your ecosystem (Peppol → UBL, ZUGFeRD → CII).