E-invoices must be created using a data format that meets the requirements of
- the European standard (EN 16931),
- and the requirements of the federal E-Invoicing Ordinance (E-Rechnungsverordnung, ERechV).
In general, invoices for the federal administration must be issued using the currently valid XRechnung standard. Other invoice formats may be used (such as ZUGFeRD version 2.1.1 or later in the XRECHNUNG profile, as a simple structured XML file) as long as they meet the above-mentioned requirements.