All public entities must receive and process invoices since 2017. Since 2019 all public administration suppliers with an entity in Estonia must also issue electronic invoices.
e-Invoicing in Estonia
Characteristics of the electronic invoice in Estonia
In accordance with European directives the electronic invoice for B2G transactions is mandatory for public administrations and their suppliers.
Ministry of Finance.
Invoices can be issued in the national XML format (EVS 923:2014/AC:2017) or the European UBL 2.1. and UN/CEFACT CII.