# UBL-SR-23

> Seller tax representative VAT identifier shall occur maximum once, if the Seller has a tax representative

Checked against Peppol BIS Billing 3.0 2026.5

Canonical: https://einvoicecheck.eu/rules/ubl-sr-23

## Official rule text

Seller tax representative VAT identifier shall occur maximum once, if the Seller has a tax representative

## Why did my invoice fail UBL-SR-23?

The Seller tax representative VAT identifier (BT-63), carried in cac:TaxRepresentativeParty/cac:PartyTaxScheme/cbc:CompanyID with a VAT tax scheme, may occur at most once. The single tax representative (BG-11) has exactly one VAT identifier, and this term is mandatory within that group.

## Common causes

- More than one VAT-scheme cac:PartyTaxScheme is written for the tax representative.
- The VAT number is emitted both with and without the country prefix as separate entries.
- A duplicate PartyTaxScheme is produced when mapping representative data.

## How do I fix it?

```
State it once: <cac:TaxRepresentativeParty>...<cac:PartyTaxScheme><cbc:CompanyID>DE123456789</cbc:CompanyID><cac:TaxScheme><cbc:ID>VAT</cbc:ID></cac:TaxScheme></cac:PartyTaxScheme></cac:TaxRepresentativeParty>. Remove additional VAT PartyTaxScheme entries.
```