(さつ)

おさつ
noun
banknote; paper money; bill
1. banknote; paper money; bill
Paper currency. The polite prefix お is usually attached. Used in everyday conversation when referring to paper money as opposed to coins.
(さつ)(はら)いたい。
I'd like to pay with bills.
財布(さいふ)にお(さつ)一枚(いちまい)(はい)っていない。
There isn't a single bill in my wallet.
この自動販売機(じどうはんばいき)はお(さつ)使(つか)えますか。
Can I use bills in this vending machine?

The base form is (さつ), but お(さつ) with the polite prefix is much more common in speech. Not to be confused with お(ふだ) (a charm or talisman from a shrine or temple). The counter for banknotes is (まい): 一万円札(いちまんえんさつ)一枚(いちまい) (one ten-thousand-yen bill). Common collocations: お(さつ)(くず)す (to break a bill into smaller denominations), お(さつ)(かぞ)える (to count bills).