Search UBL fields by name or XML path and read what each one means in plain English.
/Invoice/cbc:CustomizationID
Identifies which specification the invoice follows (e.g. Peppol BIS Billing 3.0 + EN16931).
Where: Top of the Invoice / CreditNote.
<cbc:CustomizationID>urn:cen.eu:en16931:2017#compliant#urn:fdc:peppol.eu:2017:poacc:billing:3.0</cbc:CustomizationID>/Invoice/cbc:ProfileID
The business process / Peppol profile (e.g. billing 01:1.0).
Where: Top of the Invoice / CreditNote.
<cbc:ProfileID>urn:fdc:peppol.eu:2017:poacc:billing:01:1.0</cbc:ProfileID>/Invoice/cbc:ID
The supplier's unique invoice number.
Where: Top of the Invoice / CreditNote.
<cbc:ID>INV-2025-001</cbc:ID>/Invoice/cbc:IssueDate
The date the invoice was issued, in YYYY-MM-DD format.
Where: Top of the Invoice.
<cbc:IssueDate>2025-01-31</cbc:IssueDate>/Invoice/cbc:DueDate
Payment due date in YYYY-MM-DD format.
Where: Top of the Invoice.
<cbc:DueDate>2025-02-28</cbc:DueDate>/Invoice/cac:AccountingSupplierParty
The seller's party block: name, address, tax scheme, endpoint ID.
Where: After the header fields.
<cac:AccountingSupplierParty><cac:Party>…</cac:Party></cac:AccountingSupplierParty>/Invoice/cac:AccountingCustomerParty
The buyer's party block.
Where: After the supplier party.
<cac:AccountingCustomerParty><cac:Party>…</cac:Party></cac:AccountingCustomerParty>/Invoice/cac:TaxTotal
Total VAT for the invoice, with one TaxSubtotal per VAT category.
Where: Between parties and LegalMonetaryTotal.
<cac:TaxTotal><cbc:TaxAmount currencyID="EUR">21.00</cbc:TaxAmount>…</cac:TaxTotal>/Invoice/cac:LegalMonetaryTotal
All monetary totals: line extension, tax-exclusive, tax-inclusive, payable.
Where: After TaxTotal.
<cac:LegalMonetaryTotal><cbc:PayableAmount currencyID="EUR">121.00</cbc:PayableAmount>…</cac:LegalMonetaryTotal>/Invoice/cac:InvoiceLine
A single invoice line with quantity, price and item details.
Where: One per line item.
<cac:InvoiceLine><cbc:ID>1</cbc:ID>…</cac:InvoiceLine>/Invoice/cac:AdditionalDocumentReference
References to extra documents — including the embedded PDF version of the invoice.
Where: Anywhere in the Invoice body; often near the header.
<cac:AdditionalDocumentReference><cbc:ID>INV-PDF</cbc:ID><cac:Attachment><cbc:EmbeddedDocumentBinaryObject mimeCode="application/pdf" filename="invoice.pdf">…</cbc:EmbeddedDocumentBinaryObject></cac:Attachment></cac:AdditionalDocumentReference>/Invoice/cac:AdditionalDocumentReference/cac:Attachment/cbc:EmbeddedDocumentBinaryObject
Base64-encoded binary content (typically a PDF) embedded directly in the XML.
Where: Inside an Attachment block.
<cbc:EmbeddedDocumentBinaryObject mimeCode="application/pdf" filename="invoice.pdf">JVBERi0x…</cbc:EmbeddedDocumentBinaryObject>UBL Validator and Error Explainer
Find missing fields, structural problems and Peppol issues, and read plain-English explanations.
UBL Viewer
Render a UBL XML invoice as a readable invoice summary.
Embedded PDF checker
Check whether the invoice has a valid embedded PDF attachment.
UBL totals checker
Verify line, tax and payable totals against LegalMonetaryTotal.
UBL VAT checker
Compare declared and calculated VAT per category.
Peppol BIS Billing checker
Check common Peppol BIS Billing 3.0 invoice issues.
No. UBL has hundreds of optional elements. This explainer focuses on the ones that most often cause confusion or validation issues.
They are XML namespace prefixes: cbc is the Common Basic Components namespace (simple values) and cac is the Common Aggregate Components namespace (composite blocks).