ZUGFeRD validator: check the XML inside the PDF
Drop a ZUGFeRD or Factur-X PDF. The embedded XML is extracted and checked against the EN 16931 rules.
10 free checks a day · €1 free with a key · then €0.02 per check
Processed on servers in Germany (Hetzner, Falkenstein). The uploaded file is checked in memory and not stored.
The verdict, profile, totals and every rule violation appear here.
PDF invoice → XRechnung or ZUGFeRD
A PDF, scan or photo of an invoice becomes a structured e-invoice in two steps: read the fields, then build and validate the XML.
Free in the playground: 10 checks a day per IP. With a key: €0.10 per document.
Step 1 sends the invoice text or image to a language model via OpenRouter. The uploaded file is not stored; the built e-invoice is kept 24 hours behind a signed link, then deleted.
The verdict, profile, totals and every rule violation appear here.
How a ZUGFeRD PDF is checked
A ZUGFeRD 2.x / Factur-X invoice is a PDF/A-3 with a CII XML file attached (factur-x.xml, zugferd-invoice.xml or xrechnung.xml). Since 1 January 2025 the XML is the leading part: if it differs from the visible PDF, the XML data count (BMF FAQ, question 12a).
The validator opens the PDF, finds the attachment, reads the profile from the guideline id and checks it: EN 16931 for COMFORT / EN 16931 and EXTENDED, plus KoSIT rules for the XRECHNUNG profile.
MINIMUM and BASIC WL are not EN 16931 invoices and do not meet the German e-invoice requirement (BMF FAQ, question 7); they are reported as such. ZUGFeRD 1.0 is not supported.
Deadlines
What the law requires and when. Dates from the official sources linked under each country.
Germany
Formats: XRechnung and ZUGFeRD from 2.0.1, except the MINIMUM and BASIC WL profiles.
Source: BMF: FAQ on the mandatory e-invoice ↗Belgium
Peppol BIS is built on EN 16931: the core rules are checked here, Peppol-specific rules are not.
Source: FPS Finance: from when is e-invoicing mandatory ↗Poland
KSeF uses the national FA(3) schema, which this tool does not validate. It covers EN 16931 invoices exchanged with DE, BE and FR partners.
Source: Ministry of Finance: scope of mandatory KSeF ↗Price in plain numbers
A prepaid balance, no subscription. Charged only for a successful answer; errors are free.
A new key comes with €1 of free credit: 50 validations.
Credits never expire. No subscription.
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For developers
Same checks over REST and MCP. One header, JSON out.
curl https://api.finekot.com/v1/e-invoice \
-H "Authorization: Bearer fk_live_…" \
-F file=@invoice.xml
# → {"valid":false,"errors":2,"issues":[{"rule":"BR-DE-15",…}]}
# X-Cost: 0.02curl https://api.finekot.com/v1/e-invoice \
-H "Authorization: Bearer fk_live_…" \
-H "Content-Type: application/json" \
-d '{"op":"create","output":"pdf","invoice":{…}}'
# → Factur-X PDF url + validation report · X-Cost: 0.04claude mcp add --transport http finekot https://api.finekot.com/mcp --header "Authorization: Bearer fk_live_…"
Full reference: /llms.txt · /openapi.json · /.well-known/mcp.json