Fora

If you are looking for community support for ZUGFeRD or XRechnung, apart from the obvious Stackoverflow you e.g. might

• The ZUGFeRD Community Forum
• the There is english Google group
• or, for quick questions, a chat, i.e. the [#facturx] Room in Matrix

Associations

Industry association-wise in Germany there is not only the Forum elektronische Rechnung Deutschland for ZUGFeRD but also the Verband elektronische Rechnung.

Conferences

The ZUGFeRD Entwicklertage (i.e. the ZUGFeRD Community) takes place usually annually in Bielefeld, often there is a annual FeRD-Konferenz, the E-Rechnungsgipfel and the international Exchange Summit happen more frequently.