As of 18 April 2020, public authorities at state level, as well as states and local authorities, must be able to receive electronic invoices in XRechnung format (ZUGFeRD 2.1).
From 27 November 2020, public authority contractors must also be able to send electronic invoices.
XRechnung (ZUGFeRD 2.1) affects all public institutions and authorities. It does not matter whether the contractor is from Germany or another EU country. All invoices to the authorities must be issued in XRechnung format.