registerer
/ˈrɛdʒɪst(ə)rə/noun
1A person, especially an official, who records something in a register; = registrar. Now rare.
2A person who submits something for registration; a person who is registered for something.
Origin
Late 15th century; earliest use found in John Lydgate (c1370–c1449), poet and prior of Hatfield Regis. From register + -er. Compare post-classical Latin registerarius.