The E-Invoice regulation of the federal government was implemented in order to enable all taxpayers to communicate invoices to public entities in a simple and effective manner (administration, schools, hospitals…).
As of November 27, 2020, all contractors issuing invoices to the federal administration will have to submit an electronic invoice.
As a reminder, electronic invoicing should be the leading method and similar implementations were already implemented in several european countries, such as France.
Source : Federal Ministry of Economic Affairs and Energy (in German)