German e-invoicing, done properly

Three: ZUGFeRD EN 16931 (Comfort), ZUGFeRD in the stricter XRechnung 3.0 profile, and pure XRechnung XML. With ZUGFeRD the data set is embedded as PDF/A-3 inside the readable invoice, so the same file works for people and for machines. When validating documents you have received, ZUGFeRD Extended and Basic are recognised as well.

Issuing from 2027, receiving since 2025. The duty to issue begins on 1 January 2027 for companies with more than 800,000 euro of prior-year turnover, and in 2028 for everyone else. Small businesses under § 19 UStG are permanently exempt from issuing (§ 34a UStDV) — but not from receiving.

XRechnung is pure XML; ZUGFeRD is a PDF with the same XML inside it. Both satisfy the European standard EN 16931. XRechnung is the standard for invoices to public authorities; ZUGFeRD is more convenient in ordinary trade, because the recipient can read the invoice without any e-invoicing software.

Yes, on every generation, and the result decides. It is validated against the EN 16931 business rules including the stricter German CIUS. Only a valid e-invoice is archived and may be dispatched over PEPPOL — an invalid one is handed to you to look at, so you can see what is missing.