E-Invoice Validation API

The API supports Factur-X, ZUGFeRD, XRechnung, UBL, and UN/CEFACT CII. All formats are validated against EN 16931 and their respective Schematron rule sets.

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.

Yes. Every validator has a /report variant (POST /v1/validate/{format}/report) that runs the same checks and returns a printable PDF compliance report instead of JSON. The pass/fail verdict is returned in the X-Invoice-Valid response header, and it costs one credit per call, the same as JSON validation.

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.

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.

Yes. A 30-day free trial is available with no credit card required, with enough credits to validate documents while you build and test your integration.