BR-20The Seller tax representative postal address (BG-12) shall contain a Tax representative country code (BT-69), if the Seller (BG-4) has a Seller tax representative party (BG-11).

Why does BR-20 happen?

As with the other two addresses: the country sits as free text on the last address line, or is not carried at all because it goes without saying.

What the validator checks

The expression the official KoSIT rule set evaluates — not paraphrased, but read from the Schematron file it ships. UBL and CII address different document trees, so the same rule reads differently in each.

UBL

normalize-space(cac:Country/cbc:IdentificationCode) != ''

CII

normalize-space(ram:PostalTradeAddress/ram:CountryID) != ''

Source: rule set v2026-08-31

How do you fix BR-20?

Set the ISO 3166-1 code in cac:TaxRepresentativeParty/cac:PostalAddress/cac:Country/cbc:IdentificationCode in UBL, or the representative's ram:PostalTradeAddress/ram:CountryID in CII. If you have no tax representative at all, the country code is the wrong answer: delete the BG-11 group and BR-18, BR-19 and BR-20 fall away together.

<cac:TaxRepresentativeParty>
  <cac:PostalAddress>
    <cbc:CityName>Berlin</cbc:CityName>
    <cbc:PostalZone>10115</cbc:PostalZone>
  </cac:PostalAddress>
</cac:TaxRepresentativeParty>

<cac:TaxRepresentativeParty>
  <cac:PostalAddress>
    <cbc:CityName>Berlin</cbc:CityName>
    <cbc:PostalZone>10115</cbc:PostalZone>
    <cac:Country>
      <cbc:IdentificationCode>DE</cbc:IdentificationCode>
    </cac:Country>
  </cac:PostalAddress>
</cac:TaxRepresentativeParty>