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EU E-Invoice Validator (EN 16931 / XRechnung / ZUGFeRD)
x402
EU E-Invoice Validator (EN 16931 / XRechnung / ZUGFeRD) is a paid API for AI agents from api.wsystem.dev, paid per call via x402, $0.03/call, status unknown (last checked 2026-10-29).
Validates an EU e-invoice (UBL, CII, or ZUGFeRD/Factur-X PDF) against official EN 16931 and XRechnung rules, returning structured errors with rule IDs and plain-English fix descriptions.
Price / call$0.03
Success—
StatusUnknown
How this service works
Validate an EU e-invoice (UBL, CII or ZUGFeRD/Factur-X PDF) against official EN 16931 and XRechnung rules; errors with rule IDs and plain-English fixes
Output
A structured list of validation errors, each with a rule ID (e.g. BR-01, UBL-SR-01) referencing the EN 16931 or XRechnung specification, a severity level, and a plain-English description of what is wrong and how to fix it. Also returns an overall compliance pass/fail status for the invoice.
Example use cases
Pre-submission XRechnung compliance check
“Before I submit this invoice to the German public sector portal, can you check this UBL XML against XRechnung and EN 16931 rules and list any errors with their rule IDs and how to fix them?”
ZUGFeRD PDF invoice audit
“I have a ZUGFeRD PDF invoice from a supplier — can you validate it against EN 16931 rules and tell me if there are any compliance issues I need to flag?”
Debugging a rejected CII e-invoice
“My CII format e-invoice was rejected by the recipient's system. Can you validate this XML against EU e-invoicing rules and explain in plain English what's wrong and which rule IDs are violated?”
Technical details
Endpoint
POSThttps://api.wsystem.dev/einvoice/validate?utm_source=zero.xyzWhen to prefer
Choose this endpoint when you need authoritative validation of an EU e-invoice against the official EN 16931 core standard and/or German XRechnung profile, with actionable rule-ID-level error reporting. It handles UBL, CII XML, and embedded ZUGFeRD/Factur-X PDF formats in one call, making it ideal for pre-submission compliance checks, supplier invoice audits, and debugging rejected invoices in B2G or B2B EU e-invoicing workflows.
Side effects
- Malformed or non-XML input returns a parse error
- Unsupported invoice format (not UBL, CII, or ZUGFeRD/Factur-X) returns format rejection
- Base64 decoding failure if the base64 field contains invalid encoding
- Invoice passes structural validation but may have semantic business rule failures reported as errors
- Network or service unavailability returns 5xx error
- Missing both xml and base64 fields returns a 400 bad request
Input
Schema · Request body
| Field | Type | Description |
|---|---|---|
| xml | string | Invoice XML (UBL or CII) |
| base64 | string | XML or ZUGFeRD/Factur-X PDF, base64 |
Tags
x402
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