How is the national electoral register created?

General Elections Act 1991 (as amended in 2018)

19. (1) The Commission shall make all such enquiries, and require from any person such information, as it may deem necessary for the purpose of determining whether a person is entitled to be registered as a voter or to remain so registered or where he is to be registered.

(2) The Electoral Commission shall ensure that adequate staff are deployed for the specific purpose of verifying voter qualifications and registration and shall carry out such verification both with the voter and other persons who may provide the necessary information as well as with any government departments which may have relevant information.

20. (1) All public officers in the service of the Government of Malta and all officers of bodies corporate established by law are, notwithstanding the provisions of any other law, hereby authorised and required to furnish to the Commission all information that it may require in order to be able to determine whether a person is entitled to be registered as a voter or to remain so registered. […]

Election Commission is responsible for compiling the voter register based on the data provided by various state agencies (see Articles 19-29) as well as by direct application of voters requesting to register to vote.