How is the national electoral register created?

Law No. 45 for the year 2014Regulating the Exercise of Political Rights

Chapter 3: Voter Database

Article 13

All persons, both maleand female, having the right to exercise political rights shall be registered inthe voter database. However, a person who acquired Egyptian citizenship bynaturalization shall not be registered in the voter database except after atleast five years have passed since citizenship was acquired.

Article 14

The names of thoseeligible to be voters , and is not covered by any of the conditions thatprohibits the exercise of political rights, shall be automatically registeredin the voter database, which is to be prepared based upon national IDinformation  in the database of the CivilStatus Agency of the Ministry of the Interior, around the year and at the placeand manner outlined in the by-law.

The Civil Status Agency’snational ID database is the main source for the voter database.

https://www.elections.eg/images/pdfs/laws/PoliRights2014-45.pdf