ZUGFeRD and Factur-X PDFs

A ZUGFeRD or Factur-X invoice is a PDF/A-3 with the invoice XML attached as a file, usually factur-x.xml (ZUGFeRD 2.1 and later) or zugferd-invoice.xml (ZUGFeRD 2.0). For the legal invoice, the XML counts, not the picture.

Pass the PDF bytes to validateInvoice and Summand validates the embedded XML:

const result = validateInvoice(await readFile("invoice.pdf"));
result.source; // { type: "pdf", attachmentName: "factur-x.xml", pdfConformanceLevel: "EN 16931" }

Extracting the XML

import { extractInvoiceXml, readPdf } from "@sweberdev/summand";

const found = extractInvoiceXml(bytes);
found?.xml;  // the invoice XML
found?.name; // "factur-x.xml"

readPdf(bytes).files; // all embedded files with name, MIME type and data

Summand looks at all embedded files and takes the one with a known invoice file name, otherwise the first one that is a UBL or CII invoice. Compressed object streams and cross-reference streams are supported.

What is checked about the PDF

• Whether it contains an invoice at all (SUM-PDF if not: a plain PDF is not an e-invoice).
• Whether the profile in the XMP metadata (fx:ConformanceLevel) matches the XML (SUM-PDF-LEVEL warning).
• Encrypted PDFs are not supported.

PDF/A-3 conformance itself (fonts, colour profiles, metadata schema) is not checked. Use veraPDF for that if you create PDFs.