UBL-SR-18
EN 16931-1 layer: en16931
Checked against Peppol BIS Billing 3.0 2026.5
What does UBL-SR-18 mean? Buyer VAT identifier shall occur maximum once
Why did my invoice fail UBL-SR-18?
The Buyer VAT identifier (BT-48) is expressed as a cac:PartyTaxScheme with cbc:CompanyID and a VAT tax scheme under AccountingCustomerParty/Party, and it may occur at most once. A buyer has a single VAT identifier, so more than one is invalid.
Official rule text
Buyer VAT identifier shall occur maximum once
Common causes
- Two cac:PartyTaxScheme elements with a VAT TaxScheme are emitted for the buyer.
- A VAT number is written both with and without the country prefix as separate entries.
- A non-VAT tax registration is incorrectly given the VAT scheme, producing a second VAT PartyTaxScheme.
How do I fix it?
State the VAT id once: <cac:PartyTaxScheme><cbc:CompanyID>DK16356706</cbc:CompanyID><cac:TaxScheme><cbc:ID>VAT</cbc:ID></cac:TaxScheme></cac:PartyTaxScheme>. Remove any additional VAT-scheme PartyTaxScheme for the buyer.
Related rules
UBL-SR-01 · UBL-SR-02 · UBL-SR-03 · UBL-SR-04 · UBL-SR-05 · UBL-SR-06 · UBL-SR-07 · UBL-SR-08
Check your invoice against this rule
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