#ubl

EN 16931 supports two XML syntaxes: UBL 2.1 and UN/CEFACT CII. Here's when to use each, how they differ technically, and why it matters for validation.

ZUGFeRD and XRechnung are Germany's two e-invoice formats — but they solve different problems. This guide covers the XML structures, validation rules, profile mappings, and integration patterns ERP developers need to choose the right format.