# PEPPOL-EN16931-P0105

Source: https://xmlvalid.com/rules/PEPPOL-EN16931-P0105

> Tax Category O MUST be used when exemption reason code is VATEX-EU-O

- Level: error
- Rule sets: Peppol BIS Billing 3.0 rules 3.0.21
- Context: `cac:TaxCategory[upper-case(cbc:TaxExemptionReasonCode)='VATEX-EU-O']`
- Test: `normalize-space(cbc:ID)='O'`

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