XRechnung Validator API

XRechnung is mandatory for B2G e-invoicing in Germany since November 2020 and for B2B since January 2025. Validate any XRechnung 3.0 invoice via our REST API before submission to a public-sector payee or your customer's Peppol Access Point.

German B2B mandate timeline

• · Jan 1, 2025 — all B2B issuers must accept e-invoices (XRechnung or ZUGFeRD/Factur-X)
• · Jan 1, 2027 — all B2B issuers with revenue >€800K must send e-invoices
• · Jan 1, 2028 — full B2B mandate, all sizes

What we validate

• · XRechnung 3.0.x schematron rules (BR-DE-*, BR-CO-*) — the current KoSIT configuration; legacy XRechnung 2.3.x is still accepted (?format=xrechnung-2.x)
• · UBL 2.1 and UN/CEFACT CII syntax
• · Underlying EN16931 business rules
• · Leitweg-ID validation for B2G recipients
• · German VAT category code conformance

We use Mustang 2.23.0 — a German MIT-licensed Schematron engine implementing the same KoSIT-published rule sets that the better-known phive reference engine uses. Same accuracy, modern API. Use ?format=xrechnung to always validate against the current CIUS, or pin xrechnung-3.0.

On the roadmap: XRechnung 4.0 (based on EN 16931-1:2026) — KoSIT's version for the German B2B mandate and the EU's ViDA digital-reporting requirements. We add it as soon as the validation artifacts ship; supported versions are always listed at api.eleata.io/v1/formats.