BR-E-04: Put the seller tax identifier in PartyTaxScheme when a document-level charge is exempt

The short answer

BR-E-04 fails when a charge, an cac:AllowanceCharge with cbc:ChargeIndicator of true, has a cac:TaxCategory of E and the document gives no seller tax identifier. In the recorded example the seller VAT number GB123456789 was sent as cac:PartyIdentification/cbc:ID, where no VAT rule looks for it; move it into cac:PartyTaxScheme/cbc:CompanyID under the VAT scheme.

This is a mapping slip rather than missing data, so the fix is a move. BR-E-02 fails alongside for the exempt line and clears with the same move.

What the rule checks

The rule is started by a charge whose cac:TaxCategory has cbc:ID of E under the VAT scheme. The amount and reason of the charge play no part; the 2.50 administration fee of the recorded example is only what makes the rule apply.

The seller is identified by a cbc:CompanyID in its own cac:PartyTaxScheme, under any scheme, or by a tax representative cbc:CompanyID under VAT. When tried, the fee invoice was valid with the seller scheme set to TAX, and valid with the seller tax scheme replaced by a representative holding a VAT identifier.

A seller identifier in cac:PartyIdentification/cbc:ID is ignored by this rule even when it is a VAT number, as the recorded example shows. It does count as a seller identifier for BR-CO-26, which the legal registration identifier 12345678 satisfies here anyway.

The companion finding comes from the line category. With the exempt line of the recorded example it is BR-E-02; when tried with a Standard rated line of 25.00 beside the exempt fee and no seller tax scheme, BR-S-02 was reported with this rule instead.

How an integration ends up here

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

• The seller VAT number is mapped to the party identifier because an earlier format or integration expected it there.
• An administration or handling fee inherits category E from an exempt contract, while the seller party is built from a template without a tax scheme.
• The seller tax scheme block is written only when the invoice total includes VAT.
• The seller is represented for VAT, but cac:TaxRepresentativeParty is sent without its cac:PartyTaxScheme.

How to fix it

1. Write the seller VAT number to cac:AccountingSupplierParty/cac:Party/cac:PartyTaxScheme/cbc:CompanyID with cac:TaxScheme/cbc:ID of VAT, after cac:PostalAddress and before cac:PartyLegalEntity.
2. Decide whether cac:PartyIdentification should stay. It carries the seller identifier (BT-29), which comes before cac:PostalAddress; keep it only if the seller really is identified that way. The corrected invoice drops it.
3. Keep the charge in category E at 0 if the fee shares the exemption of the service; neither its category nor its rate is at issue here.
4. Change the mapping so that the VAT number always lands in the tax scheme, whatever else the seller party carries.

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: the seller VAT number sent as a party identifier, and an exempt administration fee

<cac:AccountingSupplierParty>
  <cac:Party>
    <cbc:EndpointID schemeID="0088">7300010000001</cbc:EndpointID>
    <cac:PartyIdentification>
      <cbc:ID>GB123456789</cbc:ID>
    </cac:PartyIdentification>
    <!-- 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:AllowanceCharge>
  <cbc:ChargeIndicator>true</cbc:ChargeIndicator>
  <cbc:AllowanceChargeReason>Administration fee</cbc:AllowanceChargeReason>
  <cbc:Amount currencyID="GBP">2.50</cbc:Amount>
  <cac:TaxCategory>
    <cbc:ID>E</cbc:ID>
    <cbc:Percent>0</cbc:Percent>
    <cac:TaxScheme>
      <cbc:ID>VAT</cbc:ID>
    </cac:TaxScheme>
  </cac:TaxCategory>
</cac:AllowanceCharge>

Fragment of the corrected invoice: the same number in the seller PartyTaxScheme, and no party identification

<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>

In the failing invoice GB123456789 is the seller cac:PartyIdentification/cbc:ID and the seller has no cac:PartyTaxScheme; the corrected invoice has no party identification and carries the same number in a cac:PartyTaxScheme under VAT. The failing document also reports BR-E-02, since its exempt line of 25.00 depends on the same seller identifier. The administration fee of 2.50 and the exempt breakdown of 27.50 are unchanged.

Where it applies

• Applies to UBL Invoice and CreditNote. An exempt credit note with the fee and no seller tax scheme reported this rule and BR-E-02 when tried.
• Reported by the EN 16931 layer at the document root, once for the document however many exempt charges it has.
• Allowances have the parallel rule BR-E-03. Standard rated charges come under BR-S-04, and reverse-charge charges under BR-AE-04, which adds a buyer condition.

Related rules

• BR-E-02 fails beside this rule when the lines of the document are exempt as well
• BR-E-07 requires the exempt charge to carry a VAT rate of 0
• BR-S-04 asks for the seller identifier when a document-level charge is Standard rated
• BR-AE-04 is the reverse-charge charge rule, with a buyer condition added
• 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-E-04 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.