Grammar › N2 · 13 Obligation and permission
〜なくてはならない: must; have to
N2 · 13 Obligation and permission
Says that something is necessary or required.
Verb ない-form without い + くてはならない. Very close to 〜なければならない; both are about duty or necessity. Slightly more spoken than ならない. Casual: 〜なくちゃ. Also means 'indispensable' with nouns: なくてはならない存在.
Examples
明日は朝早く起きなくてはならない。
I have to get up early tomorrow morning.
レポートは今週中に出さなくてはなりません。
The report must be submitted this week.