The aim of the Project is to implement a secure, effective, reliable, interoperable and friendly service of registered electronic delivery in Poland, which is legally equivalent to traditional registered mail with confirmation of receipt and complies with the requirements of qualified services of registered electronic service from Regulation (EU) No 910/2014 of the European Parliament and of the Council (EIDAS Regulation). The project will implement a new public register Electronic Address Base (BAE), which stores addresses for electronic delivery of entities that wish for e-delivery instead of traditional paper delivery. Having an electronic service address entered in the BAE will enable effective bilateral correspondence with public entities, providing the parties with certainty of service, certainty of the date and time of delivery and protection against the risk of loss, theft, damage or any unauthorised alteration, as well as a fast and reliable service through the participation of a third trusted party, which may be the designated or qualified provider of a registered electronic service service. The standard of registered electronic delivery service in Poland will be developed and implemented, providing the basis for A2A e-service for A2C and A2B services, and providing uniform communication rules for all ICT systems that support the service of registered electronic delivery. The proposed solution will also ensure the functioning of a point of access to registered service services in Poland in order to allow cross-border exchange of data with addressees for e-services from the EU. The recipients of the project are:1.Public sector entities of the Republic of Poland;2.Citizens – natural persons;3.Natural persons who are entrepreneurs entered in CEIDG;4. Non-public entities who are not natural persons.