noun, na-adjective, noun which may take the genitive case particle 'no'
Refers to something being required or necessary. Often used in contexts like budgeting or planning.
旅行の入り用をリストにまとめた。
I listed the necessities for the trip.
今月は入り用が多くて大変だ。
This month we have a lot of expenses, so it's tough.
noun
Specifically refers to monetary costs or outlays. Overlaps with sense 1 but emphasizes financial expenditure.
引っ越しの入り用は予想以上にかかった。
The moving expenses cost more than expected.
Irregular kanji usage; not standard.
Compound of 入り (iri, 'entering' or 'needed') and 用 (yō, 'use' or 'business'). The exact historical derivation is uncertain, but the spelling conventionally associates with things that are required.