PEPPOL-EN16931-R005

If a separate VAT accounting currency (BT-6) is given, it must differ from the invoice currency (BT-5). The field exists only for the case where tax has to be reported in another currency.

Severity
Error
Applies to
CII, UBL
Rule set
v2026-01-31

Official rule text

VAT accounting currency code MUST be different from invoice currency code when provided.

Why does PEPPOL-EN16931-R005 happen?

The mapping fills BT-6 with the same currency as BT-5 as a precaution, because an empty field looks like a gap. The invoice then claims a currency conversion that is not happening.

How do you fix PEPPOL-EN16931-R005?

Omit BT-6 when tax and invoice share a currency: cbc:TaxCurrencyCode in UBL, ram:TaxCurrencyCode in CII. Set it only where the reporting currency genuinely differs.

In the XML

A UBL fragment. The CII path is named above — same change, different element names.

Fails
<cbc:DocumentCurrencyCode>EUR</cbc:DocumentCurrencyCode>
<cbc:TaxCurrencyCode>EUR</cbc:TaxCurrencyCode>
Fixed
<cbc:DocumentCurrencyCode>EUR</cbc:DocumentCurrencyCode>

NormAPI provides technical validation, not tax or legal advice.