# BR-AF-04 IGIC document charge requires a seller tax identifier

An Invoice that contains a Document level charge (BG-21) where the Document level charge VAT category code (BT-102) is "IGIC" shall contain the Seller VAT Identifier (BT-31), the Seller tax registration identifier (BT-32) and/or the Seller tax representative VAT identifier (BT-63).

## Problem Description

> **ERROR**: EN 16931 rule for IGIC/IPSI (Canary Islands, Ceuta, Melilla)

## Context and Significance

This is the document-charge counterpart of BR-AF-02 and BR-AF-03: a IGIC surcharge (the Canary Islands indirect tax) also requires a seller tax identifier, and the category comes from the updated EN16931 code lists supported by the current XRechnung 3.0.2 rulepack.

## Solution

Provide a seller tax identifier (BT-31, BT-32 or BT-63) whenever a document level charge uses category "L" (IGIC), e.g. seller VAT ID ESB35123456.

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

## Valid Examples

- Document level charge with category "L" (IGIC) and seller VAT ID (BT-31) ESB35123456 present

## Invalid Examples

- Document level charge with category "L" (IGIC) but no seller VAT ID, tax registration or tax representative ID anywhere

## Code Examples

### Valid XML
```
<cac:AllowanceCharge>
  <cbc:ChargeIndicator>true</cbc:ChargeIndicator>
  <cac:TaxCategory>
    <cbc:ID>L</cbc:ID>
    <cbc:Percent>7.00</cbc:Percent>
    <cac:TaxScheme><cbc:ID>VAT</cbc:ID></cac:TaxScheme>
  </cac:TaxCategory>
</cac:AllowanceCharge>
<cac:AccountingSupplierParty>
  <cac:Party>
    <cac:PartyTaxScheme>
      <cbc:CompanyID>ESB35123456</cbc:CompanyID>
      <cac:TaxScheme><cbc:ID>VAT</cbc:ID></cac:TaxScheme>
    </cac:PartyTaxScheme>
  </cac:Party>
</cac:AccountingSupplierParty>
```

### Invalid XML
```
<cac:AllowanceCharge>
  <cbc:ChargeIndicator>true</cbc:ChargeIndicator>
  <cac:TaxCategory>
    <cbc:ID>L</cbc:ID>
    <cbc:Percent>7.00</cbc:Percent>
    <cac:TaxScheme><cbc:ID>VAT</cbc:ID></cac:TaxScheme>
  </cac:TaxCategory>
</cac:AllowanceCharge>
<cac:AccountingSupplierParty>
  <cac:Party>
    <cac:PartyLegalEntity>
      <cbc:RegistrationName>Seller SL</cbc:RegistrationName>
    </cac:PartyLegalEntity>
  </cac:Party>
</cac:AccountingSupplierParty>
```

## Affected Fields

- [BT-102 Document level charge VAT category code](/resources/xrechnung/bt-102-document-level-charge-vat-category-code)
- [BT-31 Seller VAT identifier](/resources/xrechnung/bt-31-seller-vat-identifier)
- [BT-63 Seller tax representative VAT identifier](/resources/xrechnung/bt-63-seller-tax-representative-vat-identifier)

## Related Rules

- [BR-AF-02](/resources/kosit-validator-errors/br-af-02-igic-line-seller-vat-identifier-required)
- [BR-AF-03](/resources/kosit-validator-errors/br-af-03-igic-allowance-seller-vat-identifier-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.