# CII Cross Industry Invoice

The UN/CEFACT standard for cross-industry electronic invoicing. International compatibility and structured business-process coverage for global e-invoicing.

## What is CII?

CII (Cross Industry Invoice) is an XML-based standard from UN/CEFACT (United Nations Centre for Trade Facilitation and Electronic Business) for electronic invoicing. The standard is based on the UN/CEFACT D16B schema and offers a flexible, cross-industry solution for international business transactions.

> **Foundation for ZUGFeRD and Factur-X**: CII forms the XML foundation for the hybrid formats ZUGFeRD and Factur-X, enabling Europe-wide compatibility.

## Key Features

- UN/CEFACT D16B standard compliance
- International interoperability
- Structured XML syntax
- Complete business process coverage
- Flexible data modeling
- Multi-language support

## Advantages of CII Format

### Global Standardization
UN/CEFACT-based for worldwide acceptance

### Cross-Industry
Applicable in all economic sectors

### Future-Proof
Continuous development by UN/CEFACT

### Compatibility
Predictable integration with existing systems

## Implementation Levels

| Level | Requirements | Fields | Complexity |
| --- | --- | --- | --- |
| MINIMUM | Basic invoice data | ~15 mandatory fields | Low |
| BASIC WL | Extended data without line items | ~25 fields | Medium |
| BASIC | Basic line item data | ~40 fields | Medium |
| EN16931 | EU standard compliance | ~100 fields | High |
| EXTENDED | Full CII functionality | 200+ fields | Very high |

## Invoice Type Codes (UNTDID 1001)

### Commercial invoice (380)
Standard B2B invoice — the default in EN 16931. Usage: Default for most B2B transactions

### Credit note (381)
Cancels or reduces a previously issued invoice. Usage: Refunds, returns, corrections downward

### Debit note (383)
Adds charges to a previously issued invoice. Usage: Additional charges, corrections upward

### Corrected invoice (384)
Replaces an earlier invoice with corrected values. Usage: Full replacement of an earlier invoice

### Prepayment invoice (386)
Issued before delivery to request advance payment. Usage: Advance payments and deposits

### Self-billed invoice (389)
Buyer-issued invoice on the seller's behalf (Gutschrift in German). Usage: Self-billing arrangements

## Technical Specifications

| Aspect | Specification | Details |
| --- | --- | --- |
| XML Schema | UN/CEFACT D16B | CrossIndustryInvoice_100pD16B.xsd |
| Character Encoding | UTF-8 | Unicode support for international characters |
| Namespace | urn:un:unece:uncefact:data:standard | Unique XML namespace identification |
| Document Type | 380 (Commercial Invoice) | UN/EDIFACT-compliant document classification |

## Resources & Links

- [UN/CEFACT Portal](https://unece.org/trade/uncefact)
- [UN/CEFACT XML Schemas](https://unece.org/trade/uncefact/xml_schemas)
- [ZUGFeRD Format](/resources/compliance/zugferd-format)
- [UBL Universal Business Language](/resources/compliance/ubl-universal-business-language)
- [DIN EN 16931-1 Standard](/resources/compliance/din-en-16931-1-standard)