API Reference

POST /v1/generate

POST/v1/generate

Generate a compliant e-invoice from structured invoice data — EN 16931 (UBL/CII) formats, Peppol, hybrid PDF, or Italy FatturaPA FPR12 XML.

Create an e-invoice from JSON data in one API call.

Before Beliq returns the result, it validates your invoice against the rules that apply to the chosen standard. For EN 16931–based formats that means XSD, EN 16931 Schematron, and CIUS/profile Schematron where applicable. For Italy FatturaPA (standard: "fatturapa") validation is authority XSD only (no EN 16931 Schematron layer). If validation fails, you get a 422 INVALID_INVOICE response with details.

Quick copy examples

Generate XML:

generate-xml.sh

curl -X POST https://api.beliq.eu/v1/generate \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "standard": "xrechnung",
    "profile": "en16931",
    "output": "xml",
    "invoice": { ... }
  }'

Generate PDF:

generate-pdf.sh

curl -X POST https://api.beliq.eu/v1/generate \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "standard": "zugferd",
    "profile": "en16931",
    "output": "pdf",
    "invoice": { ... }
  }' \
  --output invoice.pdf

Request

POST /v1/generate
Content-Type: application/json
Authorization: Bearer <api-key>

Request body

Field	Type	Required	Description
`standard`	string	required	E-invoice standard. One of: `xrechnung`, `zugferd`, `facturx`, `peppol-bis`, `fatturapa` (Italy FatturaPA ordinaria FPR12 XML), `facturae` (Spain Facturae 3.2.2 XML), `eslog` (Slovenia e-SLOG 2.0 XML); the three national formats use XSD validation only, not EN 16931 UBL/CII
`profile`	string	optional	Compliance profile. One of: `minimum`, `basicwl`, `basic`, `en16931`, `extended`, `extended-ctc-fr`, `xrechnung`, `peppol`, `romania-ro-cius` (with `standard: "peppol-bis"` for Romania RO_CIUS, see Romania format reference), `ordinaria` (with `standard: "fatturapa"` or `"facturae"`), `eracun` (with `standard: "eslog"`, see Slovenia e-SLOG format reference). If omitted, Beliq uses the default for the chosen `standard` (`xrechnung` for `xrechnung`, `peppol` for `peppol-bis`, `ordinaria` for `fatturapa` and `facturae`, `eracun` for `eslog`, `en16931` for `zugferd`/`facturx`).
`output`	string	required	Output format. `xml` for raw XML, or `pdf`. For ZUGFeRD / Factur-X, `pdf` is a hybrid PDF/A-3 with embedded XML; for the XML-only standards (`xrechnung`, `peppol-bis`, `fatturapa`, `facturae`, `eslog`), `pdf` is a visualization PDF and requires a `template` or `pdfTemplateId`.
`invoice`	object	required	Invoice data (see Invoice object below)
`verify`	boolean	optional	When `true` (default), the engine validates output before returning it. Set `false` to skip post-generation validation (not recommended).
`template`	string	optional	Set to `"standard"` to render the built-in styled invoice layout for `pdf` output. Required to get a visualization PDF from an XML-only standard; for ZUGFeRD / Factur-X it styles the hybrid’s visible page (omit it for a blank page). See Styling the PDF.
`pdfTemplateId`	string	optional	Render the PDF from one of your stored custom templates, designed in the dashboard. The value is the template’s short ref (a `k3d-9mp`-style code shown next to it in the dashboard), not a raw UUID. Takes precedence over `template`. Requires an authenticated request (the template is org-scoped). Honoured for any `pdf` output.

Standard and output combinations

PDF output comes in two kinds. ZUGFeRD / Factur-X produce a hybrid PDF/A-3 with the legal XML embedded inside it. The XML-only standards have no hybrid form, so a PDF request returns a visualization PDF — a human-readable rendering of the same validated invoice, with no embedded XML (the legal artifact stays the XML; request it with output: "xml"). A visualization PDF requires a template or pdfTemplateId. The response’s x-pdf-kind header tells you which you received.

Standard	XML output	PDF output	XML syntax
`xrechnung`	UBL 2.1 or CII D16B	Visualization PDF (needs `template`)	CII (default) or UBL
`zugferd`	CII D22B	Hybrid PDF/A-3 with embedded CII XML	CII (D22B, ZUGFeRD 2.x)
`facturx`	CII D22B	Hybrid PDF/A-3 with embedded CII XML	CII (D22B, Factur-X 1.08)
`peppol-bis`	UBL 2.1	Visualization PDF (needs `template`)	UBL
`fatturapa`	FPR12 (Italy FatturaPA ordinaria XML)	Visualization PDF (needs `template`)	Authority XSD graph — not EN 16931 UBL/CII
`facturae`	Facturae 3.2.2 (Spain ordinaria XML)	Visualization PDF (needs `template`)	Authority XSD graph — not EN 16931 UBL/CII
`eslog`	e-SLOG 2.0 (Slovenia eracun XML)	Visualization PDF (needs `template`)	Authority XSD graph, not EN 16931 UBL/CII

Invoice object

Field	Type	Required	Constraints	Description
`number`	string	required	1–200 chars	Invoice / credit-note number
`issueDate`	string	required	`YYYY-MM-DD`	Issue date
`dueDate`	string	optional	`YYYY-MM-DD`	Payment due date
`currencyCode`	string	required	3 chars (ISO 4217)	Currency code, e.g. `EUR`
`documentType`	string	optional	`"invoice"` (default) or `"creditnote"`	Discriminates between an Invoice and a CreditNote. Supported when `standard` accepts CreditNote payloads: `peppol-bis`, `facturx`, `xrechnung`, `zugferd`, and `eslog` (e-SLOG emits document type code `381` in `S_BGM`). `fatturapa` and `facturae` accept invoices only — use `documentType: "invoice"` or omit the field. See `DOCUMENT_TYPE_STANDARD_MISMATCH`, the format overview, and Peppol Credit notes.
`precedingInvoiceReference`	object	strongly recommended on every CreditNote — see notes	`id`: 1–200 chars (the original invoice’s `number`); `issueDate` (optional): `YYYY-MM-DD`	Reference to the original invoice this credit note corrects. Emitted as UBL `cac:BillingReference / cac:InvoiceDocumentReference` on UBL outputs (Peppol BIS, XRechnung-UBL) or CII `ram:InvoiceReferencedDocument` on CII outputs (XRechnung-CII, ZUGFeRD, Factur-X). The UBL CreditNote builder fails closed without `id`; the CII CreditNote builder fails closed if the block is supplied without an `id`. EN 16931 BR-55 requires the link on every credit note, so `verify: true` (the default) will reject CreditNote output that omits it on every CreditNote-capable standard.
`buyerReference`	string	optional	Max 200 chars	Buyer’s reference (required for XRechnung B2G)
`orderReference`	string	optional	Max 200 chars	Purchase order reference
`note`	string	optional	Max 5000 chars	Free-text note
`seller`	Party	required		Seller/supplier details. For `standard: "peppol-bis"`, must include either `peppol` or a `vatId` + supported `address.countryCode` so Beliq can derive the Peppol electronic-address.
`buyer`	Party	required		Buyer/customer details. Same Peppol requirement as `seller`.
`lines`	InvoiceLine[]	required	Min 1 item	Invoice line items
`taxSummary`	TaxSummary[]	optional		VAT summary per category
`paymentMeans`	PaymentMeans	optional		Payment method details
`paymentTerms`	string	optional	Max 500 chars	Payment terms description
`totalNetAmount`	number	required		Total excluding VAT
`totalTaxAmount`	number	required		Total VAT amount
`totalGrossAmount`	number	required		Total including VAT
`franceCtc`	boolean	optional		Opt-in for the French B2B reform CTC overlay on CII (Factur-X). Ignored for `fatturapa`.
`businessProcessId`	string	optional	`S8`, `B8`, or `M8`	Flux 2 BusinessProcess code; only used when `franceCtc` is true.
`italy`	object	optional		Italy FatturaPA routing and document defaults when `standard` is `"fatturapa"`. See Italy (FatturaPA) fields.
`spain`	object	optional		Spain Facturae routing and document defaults when `standard` is `"facturae"`. See Spain (Facturae) fields.
`slovenia`	object	optional		Slovenia e-SLOG namespace when `standard` is `"eslog"`. Intentionally empty today; reserved for future Slovenia-specific fields.

Italy (FatturaPA) fields

Use the optional invoice.italy object with standard: "fatturapa" and profile: "ordinaria" (or omit profile — it defaults to ordinaria). Fields are forwarded to the engine and should follow the official formato FatturaPA documentation.

Field	Type	Description
`codiceDestinatario`	string	SDI routing code (typically 7 characters; use `0000000` for PEC-based routing per your process).
`regimeFiscale`	string	Seller fiscal regime code (e.g. `RF01`, `RF19`).
`progressivoInvio`	string	Transmission progressive id (e.g. `00001`).
`idTrasmittente`	object	Optional `{ "country": "IT", "id": "..." }` VAT override; defaults from seller `vatId` when omitted.
`tipoDocumento`	string	Document type code (e.g. `TD01`).
`condizioniPagamento`	string	Payment terms code (`TP01` / `TP02`).
`modalitaPagamento`	string	Payment means code (e.g. `MP01`, `MP05`).
`esigibilitaIVA`	string	VAT chargeability (e.g. `I`).
`causale`	string[]	Optional `Causale` lines on the Italian document.

For Italian addresses, use seller.address.region / buyer.address.region (or province) for the Provincia code when present in your data (2–3 characters).

Spain (Facturae) fields

Use the optional invoice.spain object with standard: "facturae" and profile: "ordinaria" (or omit profile — it defaults to ordinaria). All fields are optional with MINECO-aligned defaults; fields are forwarded to the engine and should follow the official Facturae format documentation.

Field	Type	Description
`modality`	string	Batch mode: `I` single invoice (default) or `L` list.
`invoiceIssuerType`	string	Issuer perspective: `EM` emitter (default), `RE` receiver, `TE` third-party.
`invoiceDocumentType`	string	Document type code, e.g. `FC` complete (default), `FA` simplified, `AF` self-billed.
`invoiceClass`	string	Invoice class code, e.g. `OO` original (default).
`taxTypeCode`	string	Tax type code, e.g. `01` IVA (default), `02` IPSI, `03` IGIC.
`languageName`	string	ISO 639-1 language code, e.g. `es` (default), `en`, `ca`, `eu`, `gl`.
`batchIdentifier`	string	Batch identifier; defaults to `BELIQ-{invoice.number}`.
`seller` / `buyer`	object	Optional per-party overrides: `{ "personTypeCode": "J" \| "F", "residenceTypeCode": "R" \| "U" \| "E" }`. Auto-derived from the party VAT and address country when omitted.

Provide Spanish-resident party vatId as a NIF/CIF (9 characters, optional ES prefix). PersonTypeCode (J legal / F natural) and ResidenceTypeCode (R Spain / U EU·EEA / E third country) are auto-derived; resident parties emit an AddressInSpain block, non-residents an OverseasAddress.

Party object

Field	Type	Required	Constraints	Description
`name`	string	required	1–200 chars	Legal name
`vatId`	string	optional	2-letter country prefix + 2–18 alphanumeric chars	VAT identification number, e.g. `DE123456789`
`taxId`	string	optional	Max 30 chars	Tax registration number
`registrationId`	string	optional	Max 50 chars	Company registration number
`email`	string	optional	Max 254 chars, valid email	Email address (required for XRechnung)
`phone`	string	optional	Max 30 chars	Phone number
`address`	Address	required		Postal address
`contactName`	string	optional	Max 200 chars	Contact person name
`peppol`	PeppolEndpoint	optional		Peppol electronic-address. Required for `standard: "peppol-bis"` if Beliq cannot derive one from `vatId` + country.

Peppol endpoint object

For Peppol BIS Billing 3.0, every party needs an electronic-address that uniquely identifies it on the Peppol Network.

Field	Type	Required	Description
`schemeId`	string	required	Peppol EAS code (e.g. `9930` for German VAT, `9957` for French VAT, `0184` for Danish DK:CVR). See the official EAS code list.
`id`	string	required	The actual identifier under that scheme (often the VAT number, sometimes a national company-registry number).

Address object

Field	Type	Required	Constraints	Description
`street`	string	optional	Max 500 chars	Street and house number
`additionalStreet`	string	optional	Max 500 chars	Additional address line
`city`	string	required	Max 200 chars	City
`postalCode`	string	required	Max 20 chars	Postal/ZIP code
`countryCode`	string	required	2 chars (ISO 3166-1 alpha-2)	Country code, e.g. `DE`
`state`	string	optional	Max 200 chars	State or province (generic)
`region`	string	optional	2–3 chars	Italian provincia / region code; used for FatturaPA `Provincia`.
`province`	string	optional	2–3 chars	Alias for `region` when mapping Italian addresses.

Invoice line object

Field	Type	Required	Constraints	Description
`description`	string	required	1–1000 chars	Item description
`quantity`	number	required	> 0	Quantity
`unitCode`	string	required	1–10 chars	UN/ECE Recommendation 20 unit code (e.g. `HUR` for hours, `C62` for units)
`unitPrice`	number	required	≥ 0	Price per unit
`lineTotal`	number	required		Line total (quantity × unitPrice)
`vatRate`	number	required	0–100	VAT rate as percentage
`vatCategoryCode`	string	required	1–10 chars	VAT category code (e.g. `S` for standard rate)
`itemId`	string	optional	Max 50 chars	Seller’s item identifier
`buyerItemId`	string	optional	Max 50 chars	Buyer’s item identifier

Tax summary object

Field	Type	Required	Constraints	Description
`vatCategoryCode`	string	required	1–10 chars	VAT category code
`vatRate`	number	required	0–100	VAT rate as percentage
`taxableAmount`	number	required		Taxable amount for this category
`taxAmount`	number	required		Tax amount for this category

Payment means object

Field	Type	Required	Constraints	Description
`typeCode`	string	required	1–10 chars	UNTDID 4461 payment means code (e.g. `30` for credit transfer, `58` for SEPA)
`iban`	string	optional	Max 34 chars	IBAN
`bic`	string	optional	Max 11 chars	BIC/SWIFT code
`bankName`	string	optional	Max 200 chars	Bank name
`paymentReference`	string	optional	Max 200 chars	Payment reference / remittance information

Response

XML output (`output: "xml"`)

When output is "xml", the response body is XML. Response headers may include x-schematron-version for EN 16931–based formats; FatturaPA responses are validated against the authority XSD graph only (see validation artifacts). The X-Version-Block response header (compact JSON) carries the full set of artifact versions in play — the same fields as the POST /v1/validate body, minus the ruleset-selection fields (rulesetChannel, rulesetFellBack), since generate always uses the current bundled artifacts and does not support Beliq-Ruleset pinning.

<?xml version="1.0" encoding="UTF-8"?>
<rsm:CrossIndustryInvoice xmlns:rsm="urn:un:unece:uncefact:data:standard:CrossIndustryInvoice:100" ...>
  ...
</rsm:CrossIndustryInvoice>

PDF output (`output: "pdf"`)

When output is "pdf", the response body is a PDF. The x-pdf-kind response header tells you which kind you received:

HTTP/1.1 200 OK
Content-Type: application/pdf
x-pdf-kind: hybrid
x-schematron-version: 1.3.16

x-pdf-kind: hybrid (ZUGFeRD / Factur-X) — a PDF/A-3 file with the legal invoice XML embedded inside it for system processing. This is the compliance artifact.
x-pdf-kind: visualization (XML-only standards) — a human-readable rendering of the invoice with no embedded XML. It is a convenience view, not a compliance artifact; fetch the legal document separately with output: "xml". Returned only when you supply a template or pdfTemplateId.

Styling the PDF

By default a hybrid PDF carries a blank visible page (the XML is what matters). To render a styled, human-readable invoice page, opt in with one of:

template: "standard" — Beliq’s built-in invoice layout. This is also what the free generator uses. For XML-only standards it is required to produce a visualization PDF.
pdfTemplateId: "k3d-9mp" — one of your own PDF templates, designed visually in the dashboard (logo, colours, fonts, layout). The value is the template’s short ref, shown next to it in the dashboard. Org-scoped, so the request must be authenticated; takes precedence over template. See the PDF template errors for the reference failures.

In every case the invoice data (parties, lines, totals) is bound by Beliq from the invoice you sent — the template only controls presentation, so the visible page can never disagree with the embedded XML.

generate-pdf-styled.sh

curl -X POST https://api.beliq.eu/v1/generate \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "standard": "facturx",
    "output": "pdf",
    "template": "standard",
    "invoice": { ... }
  }' \
  --output invoice.pdf

JSON envelope (fallback)

In some cases (for example when the upstream engine returns a JSON wrapper), the response is a JSON envelope. The data.format field mirrors the invoice syntax: "cii" for CII, "ubl" for Peppol/XRechnung UBL, or "fatturapa" for Italy FPR12.

{
  "success": true,
  "data": {
    "invoiceId": "",
    "format": "cii",
    "standard": "xrechnung",
    "profile": "en16931",
    "validationResult": {
      "valid": true,
      "format": "cii",
      "schematronVersion": "1.3.16",
      "errors": [],
      "warnings": []
    }
  }
}

Error responses

HTTP Status	Error Code	When
400	`VALIDATION_ERROR`	Request body fails JSON schema validation (missing fields, wrong types, constraint violations)
400	`UNSUPPORTED_FORMAT`	Requested standard/profile/output combination is not supported
422	`INVALID_INVOICE`	Invoice data is structurally valid but fails validation (EN 16931 / CIUS Schematron for UBL/CII, or authority XSD for `fatturapa`)
422	`PROFILE_STANDARD_MISMATCH`	The chosen `profile` is not allowed for the chosen `standard` (for example `profile: "extended"` with `standard: "peppol-bis"`). The error `details` includes `standard`, `profile`, and `allowedProfiles`.
422	`DOCUMENT_TYPE_STANDARD_MISMATCH`	`documentType: "creditnote"` with a `standard` that does not accept CreditNote payloads (for example `fatturapa`). `details`: `standard`, `documentType`, `creditNoteCapableStandards`.
400	`PDF_TEMPLATE_AUTH_REQUIRED`	`pdfTemplateId` was sent on an unauthenticated request (stored templates are org-scoped). Use your API key, or `template: "standard"`.
404	`PDF_TEMPLATE_NOT_FOUND`	The referenced `pdfTemplateId` does not exist in your organization.
422	`PDF_TEMPLATE_INVALID`	The stored template definition could not be parsed. Re-save it in the dashboard designer.
503	`ENGINE_UNAVAILABLE`	The validation engine is temporarily unavailable

422 INVALID_INVOICE example

When business rule validation fails, the error includes the full validation result in details:

{
  "success": false,
  "error": {
    "code": "INVALID_INVOICE",
    "message": "Invoice validation failed with 2 errors",
    "details": {
      "validationResult": {
        "valid": false,
        "format": "cii",
        "schematronVersion": "1.3.16",
        "errors": [
          {
            "ruleId": "BR-DE-1",
            "severity": "error",
            "location": "/rsm:CrossIndustryInvoice/...",
            "message": "An XRechnung invoice must contain the buyer reference (BT-10)."
          }
        ],
        "warnings": []
      }
    }
  }
}

Full example

generate-full.sh

curl -X POST https://api.beliq.eu/v1/generate \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "standard": "xrechnung",
    "profile": "en16931",
    "output": "xml",
    "invoice": {
      "number": "INV-2026-001",
      "issueDate": "2026-04-13",
      "dueDate": "2026-05-13",
      "currencyCode": "EUR",
      "buyerReference": "04011000-12345-03",
      "seller": {
        "name": "Acme GmbH",
        "vatId": "DE123456789",
        "email": "billing@acme.example",
        "address": {
          "street": "Musterstraße 1",
          "city": "Berlin",
          "postalCode": "10115",
          "countryCode": "DE"
        }
      },
      "buyer": {
        "name": "Bundesministerium für Beispiele",
        "vatId": "DE987654321",
        "email": "rechnung@beispiel.example",
        "address": {
          "street": "Beispielweg 42",
          "city": "Bonn",
          "postalCode": "53113",
          "countryCode": "DE"
        }
      },
      "lines": [
        {
          "description": "IT consulting — April 2026",
          "quantity": 20,
          "unitCode": "HUR",
          "unitPrice": 120.00,
          "lineTotal": 2400.00,
          "vatRate": 19,
          "vatCategoryCode": "S"
        }
      ],
      "paymentMeans": {
        "typeCode": "58",
        "iban": "DE89370400440532013000",
        "bic": "COBADEFFXXX"
      },
      "paymentTerms": "Net 30 days",
      "totalNetAmount": 2400.00,
      "totalTaxAmount": 456.00,
      "totalGrossAmount": 2856.00
    }
  }'

Italy FatturaPA ordinaria (FPR12) example

Beliq can emit FatturaPA ordinaria XML (standard: "fatturapa", default profile ordinaria). Compliance status for this profile is provisional: XSD-valid golden path, official positive samples in CI, plus a tier-honest T3 XSD structural negative (AGID FEL cross-validation) — an authority-published negative corpus URL is still absent. Beliq does not submit to Italy’s SDI interchange — you remain responsible for signing, transmission, and channel operation with your provider.

generate-fatturapa.sh

curl -X POST https://api.beliq.eu/v1/generate \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "standard": "fatturapa",
    "profile": "ordinaria",
    "output": "xml",
    "invoice": {
      "number": "123",
      "issueDate": "2014-12-18",
      "dueDate": "2015-01-30",
      "currencyCode": "EUR",
      "italy": { "codiceDestinatario": "ABC1234", "regimeFiscale": "RF19" },
      "seller": {
        "name": "Alpha SRL",
        "vatId": "IT01234567890",
        "address": {
          "street": "Via Roma 1",
          "city": "Sassari",
          "postalCode": "07100",
          "countryCode": "IT",
          "region": "SS"
        }
      },
      "buyer": {
        "name": "Beta SpA",
        "taxId": "09876543210",
        "address": {
          "street": "Via Torino 2",
          "city": "Roma",
          "postalCode": "00145",
          "countryCode": "IT",
          "region": "RM"
        }
      },
      "lines": [
        {
          "description": "Supply",
          "quantity": 5,
          "unitCode": "C62",
          "unitPrice": 1,
          "lineTotal": 5,
          "vatRate": 22,
          "vatCategoryCode": "S"
        }
      ],
      "taxSummary": [
        {
          "vatCategoryCode": "S",
          "vatRate": 22,
          "taxableAmount": 5,
          "taxAmount": 1.1
        }
      ],
      "paymentMeans": { "typeCode": "58", "iban": "IT60X0542811101000000123456" },
      "totalNetAmount": 5,
      "totalTaxAmount": 1.1,
      "totalGrossAmount": 6.1
    }
  }'

Peppol BIS Billing 3.0 example

For cross-border EU invoicing over the Peppol Network, set standard: "peppol-bis". Both parties need a Peppol electronic-address (or a vatId + country Beliq can map to the standard EAS scheme), and the invoice must carry either a buyerReference or orderReference.

generate-peppol.sh

curl -X POST https://api.beliq.eu/v1/generate \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "standard": "peppol-bis",
    "output": "xml",
    "invoice": {
      "number": "INV-2026-042",
      "issueDate": "2026-04-13",
      "currencyCode": "EUR",
      "buyerReference": "PO-2026-042",
      "seller": {
        "name": "Acme SARL",
        "vatId": "FR12345678901",
        "peppol": { "schemeId": "9957", "id": "FR12345678901" },
        "address": {
          "street": "12 Rue de Exemple",
          "city": "Paris",
          "postalCode": "75001",
          "countryCode": "FR"
        }
      },
      "buyer": {
        "name": "Voorbeeld B.V.",
        "vatId": "NL123456789B01",
        "peppol": { "schemeId": "9944", "id": "NL123456789B01" },
        "address": {
          "street": "Voorbeeldlaan 1",
          "city": "Amsterdam",
          "postalCode": "1011AB",
          "countryCode": "NL"
        }
      },
      "lines": [
        {
          "description": "Cloud subscription — April 2026",
          "quantity": 1,
          "unitCode": "MON",
          "unitPrice": 500.00,
          "lineTotal": 500.00,
          "vatRate": 21,
          "vatCategoryCode": "S"
        }
      ],
      "totalNetAmount": 500.00,
      "totalTaxAmount": 105.00,
      "totalGrossAmount": 605.00
    }
  }'

See the Peppol BIS Billing 3.0 reference for what fields Beliq emits and what the validator checks.