NCT U (엔씨티 유) is the 1st sub-unit of the boy group NCT. NCT U doesn’t have fixed members, meaning the lineup keeps changing for every comeback, OST or dance stage depending on who fits the concept of the song. NCT U debuted on April 9th, 2016 under SM Entertainment.

NCT 127 (Korean: 엔시티 127) is the 2nd sub-unit of the South Korean boy band NCT, formed and currently managed by SM Entertainment. Their unit name is a combination of the acronym for Neo Culture Technology which is the meaning for their parental group's unlimited members, and as the unit is localized in Seoul, hence the number "127" representing the longitude coordinate of the city. Originally debuted on July 1, 2016, the unit's original line up was composed of ten members: Taeil, Taeyong (leader), Yuta, Johnny, Doyoung, Jaehyun, Winwin, Jungwoo, Mark, and Haechan.

NCT Dream (엔씨티 Dream) is the 3rd sub-unit of the boy group NCT.NCT Dream has been internationally recognised as among most notable teen-aged artists of their time, known for music reflecting the growth of the youth.The sub-unit consists of 7 members: Mark, Renjun, Jeno, Haechan, Chenle, Jaemin and Jisung. NCT Dream debuted on August 24, 2016 under SM Entertainment.

WayV (Chinese: 威神V; pinyin: WēiShén V) is a Chinese boy group which serves as the 4th sub-unit and China-based unit of the South Korean boy group NCT managed by SM Entertainment's sub-label, Label V.Debuted on January 17, 2019, with their digital extended play The Vision, the group is composed of seven members: Kun, Ten, Winwin, Lucas, Xiaojun, Hendery, Yangyang.