BR-CO-18

The invoice must contain at least one VAT breakdown group (BG-23) — one block per tax category, carrying the taxable amount, the tax amount, the category and the rate.

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

Official rule text

An Invoice shall at least have one VAT breakdown group (BG-23).

Why does BR-CO-18 happen?

On an exempt invoice the block looks superfluous and gets left out. The rule wants it regardless: “no tax” is itself a statement, and it belongs in the breakdown.

How do you fix BR-CO-18?

Write one cac:TaxTotal/cac:TaxSubtotal in UBL, or one ram:ApplicableTradeTax in CII, per tax category — including E or Z, with a tax amount of zero and the exemption reason.

In the XML

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

Fails

<cac:LegalMonetaryTotal>
  <cbc:TaxExclusiveAmount currencyID="EUR">1000.00</cbc:TaxExclusiveAmount>
  <cbc:TaxInclusiveAmount currencyID="EUR">1000.00</cbc:TaxInclusiveAmount>
</cac:LegalMonetaryTotal>

Fixed

<cac:TaxTotal>
  <cbc:TaxAmount currencyID="EUR">0.00</cbc:TaxAmount>
  <cac:TaxSubtotal>
    <cbc:TaxableAmount currencyID="EUR">1000.00</cbc:TaxableAmount>
    <cbc:TaxAmount currencyID="EUR">0.00</cbc:TaxAmount>
    <cac:TaxCategory>
      <cbc:ID>E</cbc:ID>
      <cbc:Percent>0</cbc:Percent>
      <cbc:TaxExemptionReason>Kleinunternehmer nach 19 UStG</cbc:TaxExemptionReason>
      <cac:TaxScheme><cbc:ID>VAT</cbc:ID></cac:TaxScheme>
    </cac:TaxCategory>
  </cac:TaxSubtotal>
</cac:TaxTotal>
<cac:LegalMonetaryTotal>
  <cbc:TaxExclusiveAmount currencyID="EUR">1000.00</cbc:TaxExclusiveAmount>
  <cbc:TaxInclusiveAmount currencyID="EUR">1000.00</cbc:TaxInclusiveAmount>
</cac:LegalMonetaryTotal>

NormAPI provides technical validation, not tax or legal advice.