noun
Accounting term for money owed to a business by customers or clients for goods or services already delivered.
未収入金の回収に時間がかかっている。
Collecting accounts receivable is taking time.
売掛金 is the more common term for trade receivables, while 未収入金 is a broader category that can include non-trade receivables.
Compound of 未 (not yet), 収入 (income), and 金 (money).