E-Invoice Validation API
Validate Factur-X, ZUGFeRD, XRechnung, UBL and CII invoices against EN 16931 standards and Schematron rules. Get structured error reports in milliseconds.
Validate
Validate invoices against official EN 16931 standards and Schematron rules.
Validate Factur-X
Validate Factur-X invoices against EN 16931 and Schematron rules.
Validate ZUGFeRD
Verify ZUGFeRD PDF/A-3 hybrid invoices end-to-end.
Validate XRechnung
Run KoSIT validator rules against XRechnung documents.
Validate UBL
Validate UBL invoices against EN 16931 syntax binding.
Validate CII
Validate Cross Industry Invoice XML against EN 16931.
Why validate e-invoices via API?
Compliance assurance
Ensure every outgoing invoice meets EN 16931, KoSIT, and format-specific Schematron rules before submission to buyers or government portals.
Structured error reports
Receive machine-readable validation results with rule IDs, severity levels, and field-level error locations, easy to display to end users or log for audit.
Plug into any pipeline
A single REST endpoint accepts XML or PDF input. Integrate validation into your ERP, accounting software, or document processing workflow in minutes.
All major EU formats
From French Factur-X and German ZUGFeRD/XRechnung to pan-European UBL and UN/CEFACT CII, one API covers every standard you need.
Frequently asked questions
Which e-invoice formats can I validate with the API?
The API supports Factur-X, ZUGFeRD, XRechnung, UBL 2.1, and UN/CEFACT CII D16B. All formats are validated against EN 16931 and their respective Schematron rule sets.
What does the validation response contain?
The response includes a pass/fail result plus the violated rules as structured findings, split into errors and warnings. Each finding carries the rule ID, the validation layer it came from, a plain-language message, and field paths that pinpoint the issue in your document.
Does the API validate ZUGFeRD PDFs or only the embedded XML?
The Factur-X and ZUGFeRD validators accept the full hybrid PDF: the embedded XML is extracted automatically and validated against its declared profile. Container-level PDF/A-3 conformance (fonts, color profiles, metadata) is not audited; for raw XML, use the CII, UBL or XRechnung validators.
Is the validation based on official EN 16931 rules?
Yes. Validation uses the official EN 16931 Schematron rules published by CEN, supplemented by format-specific rules such as KoSIT for XRechnung and Factur-X profile rules from the FNFE-MPE.
Can I use the validation API for free?
Yes. A free tier is available with no credit card required. It covers a generous number of monthly validations, suitable for development and low-volume production use.
Start validating in minutes.
Free trial available, no credit card required. Upgrade when you need more volume.