Build invoice data into a Belgian Peppol BIS B2B E-Invoice (UBL)

Skill: Convert invoice data into a Peppol BIS Billing 3.0 UBL Invoice for Belgium's mandatory B2B regime

Region: Belgium (België / Belgique) Category: E-Invoicing — Peppol BIS Billing 3.0 (EN 16931) / Belgian B2B mandate Does: Takes invoice data (seller, buyer, lines, VAT, payment terms) and produces a UBL 2.1 Invoice that conforms to the EN 16931 semantic model and the Peppol BIS Billing 3.0 customisation, carrying the Belgian CBE/KBO enterprise number as the Peppol endpoint, Belgian VAT category codes, and the structured +++/+++ payment reference — the document a Belgian supplier sends over the Peppol network to a B2B customer. Standard: OpenPeppol BIS Billing 3.0 — CustomizationID urn:cen.eu:en16931:2017#compliant#urn:fdc:peppol.eu:2017:poacc:billing:3.0, ProfileID urn:fdc:peppol.eu:2017:poacc:billing:01:1.0, UBL 2.1 Invoice (OASIS UBL-Invoice-2.1.xsd)

From 1 January 2026 structured electronic invoicing is mandatory for most domestic B2B transactions between Belgian VAT-registered taxpayers, and the Peppol network is the default channel. This skill builds the invoice document only — the AI does not transmit it. You must send it through a certified Peppol Access Point and validate it against the official EN 16931 + Peppol BIS schematron rules before sending. Codes, mandate scope, and exemptions can change — verify against the current Peppol BIS Billing 3.0 release and the FOD Financiën / SPF Finances guidance.

When this applies

• A Belgian VAT-registered supplier issues an invoice to another Belgian VAT-registered business (domestic B2B). From 1 Jan 2026 these must be structured Peppol-BIS-compliant e-invoices, not PDF or paper.
• Out of scope: B2C invoices, transactions with non-established parties (handled via other rules), and entities benefiting from a specific exemption (e.g. bankruptcy, certain flat-rate or exempt-only taxpayers) — confirm the recipient is in scope before sending.
• If the recipient is not reachable on Peppol (no registered participant), Belgium provides the Hermes fallback: the invoice is sent to Hermes (a government-run Peppol participant), which delivers it by email as a PDF. Build the same UBL; addressing/fallback is handled by the Access Point.

Conversion procedure

1. Read the source. Accept the invoice as PDF text, CSV/JSON line data, or pasted key-value fields. Identify the seller, buyer, invoice number, issue date, due date, currency, each line (description, quantity, unit, net unit price, VAT category + rate), and payment details (IBAN, structured communication).
2. Extract identifiers. Pull both parties' CBE/KBO enterprise numbers (10 digits, formatted 0XXX.XXX.XXX) and Belgian VAT numbers (BE + 10 digits, where the 10 digits equal the enterprise number). If a required identifier is missing or ambiguous, stop and ask — never invent a VAT or enterprise number.
3. Normalize.
   • Enterprise number → digits only for the Peppol endpoint (scheme 0208); VAT number → BE0XXXXXXXXX (no dots) for cac:PartyTaxScheme/cbc:CompanyID.
   • Dates → YYYY-MM-DD.
   • Currency → ISO 4217 EUR; amounts to 2 decimals with a dot separator, no thousands separator.
   • VAT rate → numeric percentage (21, not 21%); map to a UNCL5305 VAT category code (see code tables).
   • Structured communication → the 12-digit OGM/VCS reference wrapped as +++XXX/XXXX/XXXXX+++.
4. Compute line, tax-subtotal, and document totals per the calculation rules; recompute every total — never copy a printed figure blindly.
5. Emit the UBL Invoice following the document structure and the worked example as the template. Set CustomizationID and ProfileID exactly. Include one cac:TaxSubtotal per VAT category/rate and one cac:InvoiceLine per line.
6. Validate against the checklist and the EN 16931 + Peppol BIS schematron before handing the file to the Access Point.

Source → UBL field map

Every required output field appears above. Repeat cac:TaxSubtotal once per VAT category/rate and cac:InvoiceLine once per line.

Document structure

Invoice                                        (UBL 2.1, root)
├── cbc:CustomizationID                        urn:cen.eu:en16931:2017#compliant#urn:fdc:peppol.eu:2017:poacc:billing:3.0
├── cbc:ProfileID                              urn:fdc:peppol.eu:2017:poacc:billing:01:1.0
├── cbc:ID                                     (invoice number — BT-1)
├── cbc:IssueDate                              (BT-2, YYYY-MM-DD)
├── cbc:DueDate                                (BT-9, optional)
├── cbc:InvoiceTypeCode                        (BT-3, 380 commercial)
├── cbc:DocumentCurrencyCode                   (BT-5, EUR)
├── cac:OrderReference                         (optional, buyer PO)
├── cac:AccountingSupplierParty                (seller)
│   └── cac:Party
│       ├── cbc:EndpointID schemeID="0208"     (CBE/KBO number — Peppol address)
│       ├── cac:PostalAddress (+ cac:Country IdentificationCode=BE)
│       ├── cac:PartyTaxScheme (CompanyID=BE…, TaxScheme ID=VAT)
│       └── cac:PartyLegalEntity (RegistrationName + CompanyID schemeID="0208")
├── cac:AccountingCustomerParty                (buyer — mirrors seller)
├── cac:PaymentMeans                           (optional but typical)
│   ├── cbc:PaymentMeansCode                   (30 credit transfer)
│   ├── cbc:PaymentID                          (+++/+++ structured communication)
│   └── cac:PayeeFinancialAccount/cbc:ID       (IBAN)
├── cac:PaymentTerms                           (optional, free text)
├── cac:TaxTotal                               (once; one TaxSubtotal per rate)
│   ├── cbc:TaxAmount                          (BT-110, total VAT)
│   └── cac:TaxSubtotal (repeatable)
│       ├── cbc:TaxableAmount
│       ├── cbc:TaxAmount
│       └── cac:TaxCategory (ID + Percent + TaxScheme ID=VAT)
├── cac:LegalMonetaryTotal                     (document totals)
│   ├── cbc:LineExtensionAmount
│   ├── cbc:TaxExclusiveAmount
│   ├── cbc:TaxInclusiveAmount
│   └── cbc:PayableAmount
└── cac:InvoiceLine (repeatable)
    ├── cbc:ID / cbc:InvoicedQuantity unitCode / cbc:LineExtensionAmount
    ├── cac:Item (Name + cac:ClassifiedTaxCategory ID+Percent)
    └── cac:Price/cbc:PriceAmount

Mandatory: CustomizationID, ProfileID, ID, IssueDate, InvoiceTypeCode, DocumentCurrencyCode, both parties with VAT identifiers, TaxTotal, LegalMonetaryTotal, and at least one InvoiceLine. PaymentMeans is optional in EN 16931 but expected for Belgian B2B with structured communication.

Code tables

cbc:InvoiceTypeCode (UNCL1001, common values)

Peppol/EAS electronic-address scheme IDs (schemeID on EndpointID / legal CompanyID)

VAT category codes (UNCL5305) — Belgian usage

cbc:PaymentMeansCode (UNCL4461, common)

Belgian structured communication (OGM / VCS)

A 12-digit reference rendered as +++DDD/DDDD/DDDDD+++: the first 10 digits are free, the last 2 are a check = the 10-digit number mod 97 (if the remainder is 0, use 97). Placed in cbc:PaymentID.

Calculation rules

• Line net (LineExtensionAmount) = invoiced quantity × net unit price, rounded to 2 decimals.
• Taxable amount per category (TaxSubtotal/TaxableAmount) = Σ line nets sharing that VAT category + rate, 2 decimals.
• VAT per category (TaxSubtotal/TaxAmount) = taxable amount × (Percent ÷ 100), rounded to 2 decimals. For AE/K/G/Z the amount is 0.00.
• Total VAT (TaxTotal/TaxAmount) = Σ of every TaxSubtotal/TaxAmount.
• LineExtensionAmount (document) = Σ line nets.
• TaxExclusiveAmount = Σ line nets − allowances + charges (here = Σ line nets).
• TaxInclusiveAmount = TaxExclusiveAmount + Total VAT.
• PayableAmount = TaxInclusiveAmount − any prepaid amount (here = TaxInclusiveAmount).
• Structured communication check digits = first-10-digits mod 97 (0 → 97), zero-padded to 2.
• Recompute every total from the lines; flag any mismatch with a printed source total rather than silently accepting it.

Worked example (end-to-end)

Input — pasted invoice

Seller: Voorbeeld Diensten BV — Kerkstraat 12, 9000 Gent, Belgium
        Enterprise no. 0888.222.333, VAT BE 0888.222.333, IBAN BE68 5390 0754 7034
Buyer:  Klant Industrie NV — Industrieweg 5, 2000 Antwerpen, Belgium
        Enterprise no. 0455.111.222, VAT BE 0455.111.222
Invoice F2026-0042, issued 12 March 2026, due 11 April 2026, PO 4500098765
Line 1: Consultancy services, 10 hours @ 90.00 EUR — VAT 21%
Line 2: Printed manuals, 50 units @ 8.00 EUR — VAT 6%
Structured communication: +++090/9337/55493+++

After extraction + normalization (intermediate)

{
  "invoiceNumber": "F2026-0042",
  "issueDate": "2026-03-12",
  "dueDate": "2026-04-11",
  "currency": "EUR",
  "orderRef": "4500098765",
  "seller": { "endpoint0208": "0888222333", "vat": "BE0888222333", "name": "Voorbeeld Diensten BV",
              "street": "Kerkstraat 12", "city": "Gent", "post": "9000", "country": "BE", "iban": "BE68539007547034" },
  "buyer":  { "endpoint0208": "0455111222", "vat": "BE0455111222", "name": "Klant Industrie NV",
              "street": "Industrieweg 5", "city": "Antwerpen", "post": "2000", "country": "BE" },
  "paymentId": "+++090/9337/55493+++",
  "lines": [
    { "id": "1", "desc": "Consultancy services", "qty": 10, "unit": "HUR", "price": 90.00, "net": 900.00, "vatCat": "S", "vatPct": 21 },
    { "id": "2", "desc": "Printed manuals",      "qty": 50, "unit": "C62", "price": 8.00,  "net": 400.00, "vatCat": "S", "vatPct": 6 }
  ],
  "taxSubtotals": [
    { "cat": "S", "pct": 21, "base": 900.00, "vat": 189.00 },
    { "cat": "S", "pct": 6,  "base": 400.00, "vat": 24.00 }
  ],
  "totals": { "lineExt": 1300.00, "taxExcl": 1300.00, "taxAmt": 213.00, "taxIncl": 1513.00, "payable": 1513.00 }
}

Output — Peppol BIS Billing 3.0 UBL Invoice

<?xml version="1.0" encoding="UTF-8"?>
<Invoice xmlns="urn:oasis:names:specification:ubl:schema:xsd:Invoice-2"
         xmlns:cac="urn:oasis:names:specification:ubl:schema:xsd:CommonAggregateComponents-2"
         xmlns:cbc="urn:oasis:names:specification:ubl:schema:xsd:CommonBasicComponents-2">
  <cbc:CustomizationID>urn:cen.eu:en16931:2017#compliant#urn:fdc:peppol.eu:2017:poacc:billing:3.0</cbc:CustomizationID>
  <cbc:ProfileID>urn:fdc:peppol.eu:2017:poacc:billing:01:1.0</cbc:ProfileID>
  <cbc:ID>F2026-0042</cbc:ID>
  <cbc:IssueDate>2026-03-12</cbc:IssueDate>
  <cbc:DueDate>2026-04-11</cbc:DueDate>
  <cbc:InvoiceTypeCode>380</cbc:InvoiceTypeCode>
  <cbc:DocumentCurrencyCode>EUR</cbc:DocumentCurrencyCode>
  <cac:OrderReference>
    <cbc:ID>4500098765</cbc:ID>
  </cac:OrderReference>
  <cac:AccountingSupplierParty>
    <cac:Party>
      <cbc:EndpointID schemeID="0208">0888222333</cbc:EndpointID>
      <cac:PartyName>
        <cbc:Name>Voorbeeld Diensten BV</cbc:Name>
      </cac:PartyName>
      <cac:PostalAddress>
        <cbc:StreetName>Kerkstraat 12</cbc:StreetName>
        <cbc:CityName>Gent</cbc:CityName>
        <cbc:PostalZone>9000</cbc:PostalZone>
        <cac:Country>
          <cbc:IdentificationCode>BE</cbc:IdentificationCode>
        </cac:Country>
      </cac:PostalAddress>
      <cac:PartyTaxScheme>
        <cbc:CompanyID>BE0888222333</cbc:CompanyID>
        <cac:TaxScheme>
          <cbc:ID>VAT</cbc:ID>
        </cac:TaxScheme>
      </cac:PartyTaxScheme>
      <cac:PartyLegalEntity>
        <cbc:RegistrationName>Voorbeeld Diensten BV</cbc:RegistrationName>
        <cbc:CompanyID schemeID="0208">0888222333</cbc:CompanyID>
      </cac:PartyLegalEntity>
    </cac:Party>
  </cac:AccountingSupplierParty>
  <cac:AccountingCustomerParty>
    <cac:Party>
      <cbc:EndpointID schemeID="0208">0455111222</cbc:EndpointID>
      <cac:PartyName>
        <cbc:Name>Klant Industrie NV</cbc:Name>
      </cac:PartyName>
      <cac:PostalAddress>
        <cbc:StreetName>Industrieweg 5</cbc:StreetName>
        <cbc:CityName>Antwerpen</cbc:CityName>
        <cbc:PostalZone>2000</cbc:PostalZone>
        <cac:Country>
          <cbc:IdentificationCode>BE</cbc:IdentificationCode>
        </cac:Country>
      </cac:PostalAddress>
      <cac:PartyTaxScheme>
        <cbc:CompanyID>BE0455111222</cbc:CompanyID>
        <cac:TaxScheme>
          <cbc:ID>VAT</cbc:ID>
        </cac:TaxScheme>
      </cac:PartyTaxScheme>
      <cac:PartyLegalEntity>
        <cbc:RegistrationName>Klant Industrie NV</cbc:RegistrationName>
        <cbc:CompanyID schemeID="0208">0455111222</cbc:CompanyID>
      </cac:PartyLegalEntity>
    </cac:Party>
  </cac:AccountingCustomerParty>
  <cac:PaymentMeans>
    <cbc:PaymentMeansCode>30</cbc:PaymentMeansCode>
    <cbc:PaymentID>+++090/9337/55493+++</cbc:PaymentID>
    <cac:PayeeFinancialAccount>
      <cbc:ID>BE68539007547034</cbc:ID>
    </cac:PayeeFinancialAccount>
  </cac:PaymentMeans>
  <cac:PaymentTerms>
    <cbc:Note>Payment within 30 days, structured communication +++090/9337/55493+++</cbc:Note>
  </cac:PaymentTerms>
  <cac:TaxTotal>
    <cbc:TaxAmount currencyID="EUR">213.00</cbc:TaxAmount>
    <cac:TaxSubtotal>
      <cbc:TaxableAmount currencyID="EUR">900.00</cbc:TaxableAmount>
      <cbc:TaxAmount currencyID="EUR">189.00</cbc:TaxAmount>
      <cac:TaxCategory>
        <cbc:ID>S</cbc:ID>
        <cbc:Percent>21</cbc:Percent>
        <cac:TaxScheme>
          <cbc:ID>VAT</cbc:ID>
        </cac:TaxScheme>
      </cac:TaxCategory>
    </cac:TaxSubtotal>
    <cac:TaxSubtotal>
      <cbc:TaxableAmount currencyID="EUR">400.00</cbc:TaxableAmount>
      <cbc:TaxAmount currencyID="EUR">24.00</cbc:TaxAmount>
      <cac:TaxCategory>
        <cbc:ID>S</cbc:ID>
        <cbc:Percent>6</cbc:Percent>
        <cac:TaxScheme>
          <cbc:ID>VAT</cbc:ID>
        </cac:TaxScheme>
      </cac:TaxCategory>
    </cac:TaxSubtotal>
  </cac:TaxTotal>
  <cac:LegalMonetaryTotal>
    <cbc:LineExtensionAmount currencyID="EUR">1300.00</cbc:LineExtensionAmount>
    <cbc:TaxExclusiveAmount currencyID="EUR">1300.00</cbc:TaxExclusiveAmount>
    <cbc:TaxInclusiveAmount currencyID="EUR">1513.00</cbc:TaxInclusiveAmount>
    <cbc:PayableAmount currencyID="EUR">1513.00</cbc:PayableAmount>
  </cac:LegalMonetaryTotal>
  <cac:InvoiceLine>
    <cbc:ID>1</cbc:ID>
    <cbc:InvoicedQuantity unitCode="HUR">10</cbc:InvoicedQuantity>
    <cbc:LineExtensionAmount currencyID="EUR">900.00</cbc:LineExtensionAmount>
    <cac:Item>
      <cbc:Name>Consultancy services</cbc:Name>
      <cac:ClassifiedTaxCategory>
        <cbc:ID>S</cbc:ID>
        <cbc:Percent>21</cbc:Percent>
        <cac:TaxScheme>
          <cbc:ID>VAT</cbc:ID>
        </cac:TaxScheme>
      </cac:ClassifiedTaxCategory>
    </cac:Item>
    <cac:Price>
      <cbc:PriceAmount currencyID="EUR">90.00</cbc:PriceAmount>
    </cac:Price>
  </cac:InvoiceLine>
  <cac:InvoiceLine>
    <cbc:ID>2</cbc:ID>
    <cbc:InvoicedQuantity unitCode="C62">50</cbc:InvoicedQuantity>
    <cbc:LineExtensionAmount currencyID="EUR">400.00</cbc:LineExtensionAmount>
    <cac:Item>
      <cbc:Name>Printed manuals</cbc:Name>
      <cac:ClassifiedTaxCategory>
        <cbc:ID>S</cbc:ID>
        <cbc:Percent>6</cbc:Percent>
        <cac:TaxScheme>
          <cbc:ID>VAT</cbc:ID>
        </cac:TaxScheme>
      </cac:ClassifiedTaxCategory>
    </cac:Item>
    <cac:Price>
      <cbc:PriceAmount currencyID="EUR">8.00</cbc:PriceAmount>
    </cac:Price>
  </cac:InvoiceLine>
</Invoice>

Normalisations shown: VAT BE 0888.222.333 → BE0888222333 (dots stripped); enterprise no. → 0888222333 on EndpointID schemeID="0208"; dates 12 March 2026 → 2026-03-12; rate 21% → 21; line 1 net recomputed 10 × 90.00 = 900.00; line 2 net 50 × 8.00 = 400.00; VAT recomputed 900.00 × 21% = 189.00 and 400.00 × 6% = 24.00; total VAT 189.00 + 24.00 = 213.00; TaxInclusiveAmount 1300.00 + 213.00 = 1513.00. The structured communication 090/9337/55493 checks out: 0909337554 mod 97 = 93. The Access Point routes by the buyer EndpointID (0208:0455111222); if that participant is not registered, the same UBL is delivered through Hermes to the buyer by email.

Validation checklist

• All required fields extracted; AI asked about anything missing or ambiguous (no invented VAT or enterprise numbers, dates, or amounts)
• CustomizationID = urn:cen.eu:en16931:2017#compliant#urn:fdc:peppol.eu:2017:poacc:billing:3.0 and ProfileID = urn:fdc:peppol.eu:2017:poacc:billing:01:1.0, exactly
• Both parties carry EndpointID schemeID="0208" (CBE/KBO number) and a PartyTaxScheme/CompanyID = BE + 10 digits
• InvoiceTypeCode = 380 for a commercial invoice (credit notes use a CreditNote document)
• Dates in YYYY-MM-DD; DocumentCurrencyCode = EUR; amounts 2dp dot-decimal with currencyID="EUR"
• Each VAT category uses a valid UNCL5305 code (S/Z/E/AE/K/G/O) with the correct Percent
• One cac:TaxSubtotal per VAT category+rate; TaxAmount = TaxableAmount × Percent/100 (2dp)
• TaxTotal/TaxAmount = Σ subtotals; LineExtensionAmount = Σ line nets; TaxInclusiveAmount = TaxExclusiveAmount + TaxAmount; PayableAmount correct
• Structured communication formatted +++XXX/XXXX/XXXXX+++ with valid mod-97 check digits, placed in cbc:PaymentID
• At least one cac:InvoiceLine; line LineExtensionAmount = quantity × PriceAmount
• Document validated against the OASIS UBL 2.1 Invoice XSD and the EN 16931 + Peppol BIS Billing 3.0 schematron before sending via a certified Access Point (or Hermes fallback)

Last updated: 2026-06-13 — verify the active Peppol BIS Billing 3.0 CustomizationID/ProfileID, the EAS/scheme code (0208), the Belgian B2B mandate scope and exemptions, and the Hermes fallback rules against the current OpenPeppol release and FOD Financiën / SPF Finances guidance before use.