Electronic invoicing with UBL 2.1 and Peppol BIS 3.0
Electronic invoicing is becoming mandatory in many European countries. Discover how the UBL 2.1 format and the Peppol network simplify B2B and B2G exchanges.
Why electronic invoicing?
Electronic invoicing (e-invoicing) replaces paper and PDF invoices with structured XML messages. It reduces processing costs, accelerates payments, and facilitates automated tax controls.
In Europe, Directive 2014/55/EU mandates e-invoicing for public procurement. Many countries are now extending this obligation to the private sector (France, Belgium, Germany...).
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UBL 2.1 invoice structure
A Peppol BIS 3.0 invoice is a UBL 2.1 XML file. Here is a simplified example:
<Invoice xmlns="urn:oasis:names:specification:ubl:schema:xsd:Invoice-2">
<ID>INV-2026-001</ID>
<IssueDate>2026-01-28</IssueDate>
<DueDate>2026-02-27</DueDate>
<InvoiceTypeCode>380</InvoiceTypeCode>
<DocumentCurrencyCode>EUR</DocumentCurrencyCode>
<AccountingSupplierParty>
<Party>
<PartyName><Name>ACME SA</Name></PartyName>
<EndpointID schemeID="0088">1234567890128</EndpointID>
</Party>
</AccountingSupplierParty>
<LegalMonetaryTotal>
<TaxExclusiveAmount currencyID="EUR">1000.00</TaxExclusiveAmount>
<TaxInclusiveAmount currencyID="EUR">1210.00</TaxInclusiveAmount>
<PayableAmount currencyID="EUR">1210.00</PayableAmount>
</LegalMonetaryTotal>
</Invoice>Peppol BIS 3.0 validation rules
Peppol enforces business rules (PINT/BR) in addition to XSD validation:
BR-01
The invoice must have a unique identifier (ID)
BR-04
The issue date is mandatory
BR-CO-15
Total with tax = total without tax + tax amount
BR-S-08
VAT rate must be specified for each taxable line
BR-E-01
VAT exemption reason must be provided when tax category is E (exempt).
BR-AE-01
Tax category AE (reverse charge) requires a tax exemption reason.
BR-CO-09
Seller VAT identifier or tax registration number must be present.
BR-CO-26
Advance payments must be reflected in the invoice total.
Peppol network: how does it work?
Peppol (Pan-European Public Procurement OnLine) is a standardized exchange network. Companies connect through a certified Access Point. Documents are routed via the network using Peppol identifiers (GLN, VAT number...).
To send an invoice on Peppol, your UBL file must comply with BIS 3.0 rules. That's where a validator like ValidateFin becomes essential before sending.
The Peppol network currently connects over 300,000 businesses across more than 70 countries. Any company registered with a certified Access Point can send and receive documents to any other participant worldwide.
UBL 2.1 mandatory elements
A valid Peppol BIS 3.0 invoice must include the following mandatory fields:
- Invoice ID (BT-1) — Unique identifier assigned by the seller.
- Issue Date (BT-2) — The date the invoice was issued.
- Invoice Type Code (BT-3) — 380 for Invoice, 381 for Credit Note.
- Currency (BT-5) — ISO 4217 currency code (e.g., EUR).
- Seller (BT-27) — Legal name of the supplier.
- Buyer (BT-44) — Legal name of the buyer.
- Tax total (BT-110) — Total VAT amount on the invoice.
- Line net amount (BT-131) — Net amount for each invoice line.
- Tax exclusive amount (BT-109) — Total amount excluding VAT.
- Tax inclusive amount (BT-112) — Total amount including VAT.
How to connect to Peppol
Sending invoices on the Peppol network requires a few setup steps:
- Choose an Access Point — Select a certified Peppol Access Point provider (e.g., Basware, Pagero, Storecove).
- Register your identifier — Your AP registers your business identifier (VAT, KBO, DUNS...) in the Peppol SMP.
- Configure document types — Declare which document types you can send and receive (BIS Billing 3.0 Invoice, CreditNote).
- Validate your files — Before sending, validate each invoice against Peppol BIS 3.0 rules using ValidateFin.
- Send via AS4 — Your AP transmits the invoice to the receiver's AP using the AS4 messaging protocol.
ValidateFin allows you to validate your UBL invoices before submitting them to your Access Point, avoiding costly rejections.
Validate your UBL invoice
Our UBL / Peppol validator checks structural compliance (XSD) and Peppol BIS 3.0 business rules. View all invoice lines and fix errors before sending.
Validate my UBL invoiceFrequently Asked Questions
What is UBL 2.1 and how does it relate to Peppol?
UBL 2.1 (Universal Business Language) is an XML standard for electronic business documents including invoices and credit notes. Peppol BIS Billing 3.0 is a specification built on top of UBL 2.1 that adds specific business rules for e-invoicing across the Peppol network, implementing the European EN 16931 standard.
What Peppol BIS 3.0 business rules does the validator check?
The validator checks dozens of business rules including: VAT category consistency, line item total calculations, mandatory supplier/buyer identification, payment terms validation, allowance and charge calculations, and document-level total reconciliation.
Can I validate both UBL invoices and credit notes?
Yes. ValidateFin's UBL Validator supports both UBL 2.1 Invoice and Credit Note document types. The same Peppol BIS 3.0 and EN 16931 rules apply to both, with specific rules activated for credit notes.
What is the difference between EN 16931 and Peppol BIS 3.0?
EN 16931 is the European standard for electronic invoicing (a core invoice model). Peppol BIS 3.0 is a specific implementation of EN 16931, adding Peppol-specific business rules and constraints for use on the Peppol network.
Which countries use Peppol for e-invoicing?
Peppol is widely used in Norway, Sweden, Denmark, Finland, Belgium, the Netherlands, Australia, New Zealand, and Singapore. France, Germany, and Italy are expanding Peppol adoption for both B2G and B2B e-invoicing.
What is a Peppol Access Point?
A Peppol Access Point (AP) is a certified service provider that connects your business to the Peppol network. It handles document transmission using the AS4 messaging protocol, SMP lookups, and digital signing.
How do I find my Peppol participant identifier?
Your Peppol participant identifier is registered by your Access Point provider. It typically uses your VAT number or national business identifier (e.g., KBO for Belgium, KvK for Netherlands) with a scheme prefix.
Can I send other document types via Peppol besides invoices?
Yes. The Peppol network supports multiple document types including Purchase Orders (BIS Order 3), Order Responses, Despatch Advice, Catalogue, and Invoice Response messages, all using UBL 2.1 or CII XML.
What happens if a Peppol invoice fails validation?
If your invoice fails Peppol BIS 3.0 validation, it will be rejected by your Access Point or the receiver's Access Point. Using ValidateFin before submission allows you to catch and fix errors before they cause costly rejections.
Is ValidateFin compatible with NLCIUS and XRechnung?
ValidateFin validates against Peppol BIS 3.0 and EN 16931 core rules, which cover the majority of NLCIUS (Netherlands) and XRechnung (Germany) requirements. Country-specific extensions may require additional checks.