BR-Z-02: Add the seller VAT identifier when lines are Zero rated

The short answer

BR-Z-02 fails when a line's cac:ClassifiedTaxCategory has cbc:ID of Z under the VAT scheme and the document has neither a seller tax identifier, under any scheme, nor a tax representative VAT identifier. Add the seller's VAT number, GB123456789 in the recorded example, in cac:AccountingSupplierParty/cac:Party/cac:PartyTaxScheme/cbc:CompanyID with the VAT tax scheme.

A Zero rated supply is a taxable supply charged at 0. No tax is due on the invoice, but the seller's VAT registration still belongs on it.

What the rule checks

A single Zero rated line, in cac:InvoiceLine or cac:CreditNoteLine, triggers the rule. The document then needs either a cbc:CompanyID in any seller cac:PartyTaxScheme, or a tax representative cbc:CompanyID under the VAT scheme.

Both routes worked when tried on the Zero rated invoice: a seller cac:PartyTaxScheme under scheme TAX in place of VAT, and no seller identifier but a tax representative with GB987654321 under VAT, each passed every layer.

One missing identifier is reported once for each kind of content that needs it. When tried, the rich example invoice without its seller cac:PartyTaxScheme reported BR-S-02, BR-S-03, BR-S-04 and this rule together; putting the identifier back clears all four.

The seller legal registration identifier is no substitute, although it does keep BR-CO-26 quiet. With 12345678 removed from cac:PartyLegalEntity as well, the failing invoice reported BR-CO-26 next to this rule.

How an integration ends up here

Possible causes, from the shape of the rule rather than from measured usage:

• The seller party is filled in from tax settings that were only set up for Standard rated sales, so a document with nothing but Zero rated lines goes out without a VAT number.
• The export skips cac:PartyTaxScheme when the VAT total is 0.00, on the mistaken view that no VAT identification is needed where no VAT is charged.
• A seller trading through a tax representative sends the representative without its cac:PartyTaxScheme.
• The VAT number is written into the legal entity or party identification elements, where it does not count.

How to fix it

1. Take the seller's VAT registration number, prefix included, from the seller's company record.
2. Write it into the seller party as cac:PartyTaxScheme/cbc:CompanyID with cac:TaxScheme/cbc:ID of VAT, after cac:PostalAddress and before cac:PartyLegalEntity.
3. Emit the seller cac:PartyTaxScheme whenever the seller has a VAT number, whatever the VAT total of the document.
4. If the seller is not VAT registered, category Z is the value to question. Agree the right treatment with whoever owns the tax setup; not subject to VAT (O) is a different category with rules of its own.

Validate your corrected invoice

Before and after

These are fragments, not complete documents. The complete synthetic documents they come from are linked below.

Fragment of the failing invoice: a Zero rated line, and a seller party with no PartyTaxScheme

<cac:AccountingSupplierParty>
  <cac:Party>
    <cbc:EndpointID schemeID="0088">7300010000001</cbc:EndpointID>
    <!-- postal address omitted from this fragment -->
    <cac:PartyLegalEntity>
      <cbc:RegistrationName>Example Supplier Ltd</cbc:RegistrationName>
      <cbc:CompanyID>12345678</cbc:CompanyID>
    </cac:PartyLegalEntity>
  </cac:Party>
</cac:AccountingSupplierParty>

<cac:InvoiceLine>
  <cbc:ID>1</cbc:ID>
  <!-- quantity and line amount omitted from this fragment -->
  <cac:Item>
    <cbc:Name>Example service</cbc:Name>
    <cac:ClassifiedTaxCategory>
      <cbc:ID>Z</cbc:ID>
      <cbc:Percent>0</cbc:Percent>
      <cac:TaxScheme>
        <cbc:ID>VAT</cbc:ID>
      </cac:TaxScheme>
    </cac:ClassifiedTaxCategory>
  </cac:Item>
  <!-- price omitted from this fragment -->
</cac:InvoiceLine>

Fragment of the corrected invoice: the seller is identified for VAT although the invoice carries no VAT

<cac:AccountingSupplierParty>
  <cac:Party>
    <cbc:EndpointID schemeID="0088">7300010000001</cbc:EndpointID>
    <!-- postal address omitted from this fragment -->
    <cac:PartyTaxScheme>
      <cbc:CompanyID>GB123456789</cbc:CompanyID>
      <cac:TaxScheme>
        <cbc:ID>VAT</cbc:ID>
      </cac:TaxScheme>
    </cac:PartyTaxScheme>
    <cac:PartyLegalEntity>
      <cbc:RegistrationName>Example Supplier Ltd</cbc:RegistrationName>
      <cbc:CompanyID>12345678</cbc:CompanyID>
    </cac:PartyLegalEntity>
  </cac:Party>
</cac:AccountingSupplierParty>

The corrected invoice has the seller cac:PartyTaxScheme with GB123456789 under the VAT scheme, and the failing one has no cac:PartyTaxScheme in the seller party; nothing else differs. The failing document reports only BR-Z-02, because its single line is Zero rated and nothing in it is Standard rated.

Where it applies

• Applies to UBL Invoice and CreditNote. A Zero rated credit note without the seller identifier reported this rule alone when tried.
• Reported by the EN 16931 layer as a fatal finding at the document root, once however many lines are Zero rated.
• Zero rated document-level allowances and charges have their own versions, BR-Z-03 and BR-Z-04. Standard rated lines have BR-S-02.

Related rules

• BR-S-02 requires the same seller identifier for Standard rated lines
• BR-Z-03 applies the requirement to Zero rated document-level allowances
• BR-Z-04 applies the requirement to Zero rated document-level charges
• BR-CO-26 is reported too when the seller legal registration identifier is also missing
• Browse every rule in the reference
• Background: Understanding EN 16931 validation errors

Scope and source

Written for Peppol BIS Billing 3.0.21 (May 2026), EN 16931 1.3.16, as applied to UBL 2.1 Invoice and CreditNote documents. Other profiles, syntaxes and releases can define this identifier differently. Guidance version 2026-09-28.1: source checked 2026-09-28, explanation last updated 2026-09-28.

The official definition of BR-Z-02 carries the normative wording and test. This page is our explanation of it, not a copy.

Guidance does not change the engine verdict. Fixing this finding does not mean the document passes every layer, and validation does not certify legal or tax compliance or transmit a document over Peppol.