Antiphon

Modern European e-invoicing, native to .NET.

Antiphon brings European e-invoicing standards directly into the .NET ecosystem, integrated into your application rather than dependent on external online services, Java sidecars, or other non-native infrastructure.

Generate, validate, parse, and work with standards-compliant electronic invoices through familiar .NET APIs. Antiphon handles the complexity of the underlying standards so your invoicing functionality remains part of your code, your architecture, and your infrastructure.

Your code. Your infrastructure. No sidecars required.

The free browser-based validator is available now. It checks XRechnung, Peppol BIS Billing 3.0, Factur-X, and EN 16931 invoice XML against their Schematron business rules, entirely in your browser — nothing you paste ever leaves the page.

The SDK is Available Now

Antiphon.Invoicing is published on NuGet, covering EN 16931 core, Peppol BIS Billing 3.0 (UBL and CII), XRechnung (UBL and CII), and Factur-X PDF generation — compiled directly from the standards bodies' own Schematron rule sets, not reimplemented from scratch. Evaluation mode is free and fully functional today, with nothing disabled.

Commercial licensing isn't purchasable yet — the EULA is still working its way through review — but early inquiries are welcome and get priority consideration once it opens.