# BR-04 Invoice type code is required

An invoice shall have an Invoice type code (BT-3) identifying the functional type of the document, such as a commercial invoice or a credit note.

## Problem Description

> **ERROR**: EN 16931 core business rule (CEN)

## Context and Significance

This is an EN 16931 core rule. The type code tells the recipient whether to process the document as an invoice, a corrected invoice or a credit note; national rules such as BR-DE-17 narrow the accepted codes further. Neither the UBL nor the CII schema requires the element, so an export that omits it passes the schema check and fails only on BR-04.

## Solution

Add cbc:InvoiceTypeCode with an allowed UNTDID 1001 code, for example 380 for a commercial invoice or 384 for a corrected invoice. In UBL, issue a credit note (381) as a CreditNote document with cbc:CreditNoteTypeCode; BR-CL-01 rejects 381 in cbc:InvoiceTypeCode. In CII, the code is rsm:ExchangedDocument/ram:TypeCode.

- [Validate XML](/en/xrechnung-validator?source=resource&rule=BR-04)
- [Convert invoice](/en/pdf-to-xrechnung?source=resource&rule=BR-04)

## Valid Examples

- BT-3 = 380 — commercial invoice
- BT-3 = 381 — credit note (in UBL as cbc:CreditNoteTypeCode in a CreditNote document)

## Invalid Examples

- cbc:InvoiceTypeCode element is missing from the invoice header

## Code Examples

### Valid XML
```
<cbc:InvoiceTypeCode>380</cbc:InvoiceTypeCode>
<cbc:DocumentCurrencyCode>EUR</cbc:DocumentCurrencyCode>
```

### Invalid XML
```
<cbc:IssueDate>2024-05-01</cbc:IssueDate>
<cbc:DocumentCurrencyCode>EUR</cbc:DocumentCurrencyCode>
```

## Affected Fields

- [BT-3 Invoice type code](/resources/xrechnung/bt-3-invoice-type-code)

## Related Rules

- [BR-02](/resources/kosit-validator-errors/br-02-invoice-number-required)
- [BR-03](/resources/kosit-validator-errors/br-03-invoice-issue-date-required)

## Validation Tools

- [Official KoSIT Validator](https://github.com/itplr-kosit/validator): Run the official KoSIT validator with the XRechnung configuration to check EN 16931 and XRechnung rules.
- [Convert PDF to XRechnung](/pdf-to-xrechnung): Find validation errors during conversion and review each correction.

## Related Resources

- [Official Specification](https://docs.peppol.eu/poacc/billing/3.0/rules/ubl-tc434/)
- [Test Suite](https://github.com/itplr-kosit/xrechnung-testsuite)
- [All validation errors](/resources/kosit-validator-errors): Overview of the EN 16931, XRechnung and Peppol validation rules explained here.