# BH-ZF1-01 — ZUGFeRD 1.0 detected (legacy)

> https://billhorse.com/en/rules/bh-zf1-01/

## What does this error mean?

ZUGFeRD 1.0 is not EN 16931 conformant and does not satisfy e-invoicing mandates.

## How to fix it

Migrate to ZUGFeRD 2.x/Factur-X (EN 16931 profile) or XRechnung — the data models are similar, mapping effort is moderate.