Side-by-Side Comparison
| 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
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.
CII
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.
Key Differences Explained
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.
When to Use UBL
- ·Connecting to Peppol network (required)
- ·Invoicing internationally
- ·Working with UK, Nordic, Belgian businesses
- ·Your ERP exports UBL natively
When to Use CII
- ·Creating ZUGFeRD or Factur-X invoices (required)
- ·Trading primarily France/Germany
- ·Want smaller file sizes
- ·Your ERP exports CII natively
Can You Use Both?
If you use XRechnung, you can choose either syntax—both are valid. Most implementations pick one and stick with it.
Conversion between UBL and CII is possible since both map to EN 16931, though some edge cases may require attention.
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