To actively leave a membership or group by oneself (active action).
When to use
voluntary withdrawal, active action, self-initiated exit
The nuance
Use when the subject actively leaves a group or organization on their own will.
탈퇴하다 (tal-toe-ha-da, taltoehada) · 탈퇴되다 (tal-toe-doe-da, taltoedoeda)
'탈퇴하다' means to actively leave a group by oneself, while '탈퇴되다' indicates being removed or forced out passively by someone else or by automatic process.

One lane per word — no nested boxes, just the gist.
To actively leave a membership or group by oneself (active action).
When to use
voluntary withdrawal, active action, self-initiated exit
The nuance
Use when the subject actively leaves a group or organization on their own will.
To be removed or forced out of membership by someone else or by a system (passive situation).
When to use
forced withdrawal, automatic system removal, passive exit
The nuance
Use when the subject is passively removed or withdrawn due to external factors or system actions.
저는 동호회에서 탈퇴했어요.
jeo-neun dong-ho-hoe-e-seo tal-toe-haess-eo-yo., jeo neun dong ho hoe e seo tal toe haess eo yo.
The subject actively left, so 탈퇴하다 is correct.
저는 동호회에서 탈퇴되었어요.
jeo-neun dong-ho-hoe-e-seo tal-toe-doe-eoss-eo-yo., jeo neun dong ho hoe e seo tal toe doe eoss eo yo.
The subject was passively removed, so 탈퇴되다 is correct.
관리자가 회원을 탈퇴했어요.
gwan-ri-ja-ga hoe-won-eul tal-toe-haess-eo-yo., gwan ri ja ga hoe won eul tal toe haess eo yo.
'탈퇴하다' is only for self-action; here, '탈퇴시키다' should be used.
회원이 탈퇴되었어요.
hoe-won-i tal-toe-doe-eoss-eo-yo., hoe won i tal toe doe eoss eo yo.
Passive removal fits 탈퇴되다 naturally.
회원이 탈퇴했어요.
hoe-won-i tal-toe-haess-eo-yo., hoe won i tal toe haess eo yo.
Member actively left, so 탈퇴하다 is correct.
시스템이 회원을 탈퇴했어요.
si-seu-tem-i hoe-won-eul tal-toe-haess-eo-yo., si seu tem i hoe won eul tal toe haess eo yo.
System action requires '탈퇴시키다' or '탈퇴 처리하다', not 탈퇴하다.
자동으로 탈퇴되었어요.
ja-dong-eu-ro tal-toe-doe-eoss-eo-yo., ja dong eu ro tal toe doe eoss eo yo.
Passive automatic removal fits 탈퇴되다.
저는 자동으로 탈퇴했어요.
jeo-neun ja-dong-eu-ro tal-toe-haess-eo-yo., jeo neun ja dong eu ro tal toe haess eo yo.
Active 탈퇴하다 doesn't fit automatic passive removal; use 탈퇴되다.
Which word is used when a member leaves a group voluntarily?
Which is appropriate when a manager forcibly removes a member?
Which word describes automatic removal by a system?