1.
as needed; as required; as necessary; when the need arises
Used to indicate that something should be done when the situation calls for it, not automatically or always.
必要に応じて調整する。
I'll adjust as needed.
A set phrase meaning "according to necessity" or "when needed." Composed of 必要 (necessity) + に (particle) + 応じて (in response to; according to). Widely used in business, instructions, and official documents.
Common patterns
Usage
Slightly formal. Common in manuals, guidelines, workplace instructions, and official communication. In casual speech, 必要なら (if necessary) is a simpler alternative.