Money paid in advance to secure a reservation, booking, or order. Common in contexts like hotels, travel, and purchases.
I paid 10,000 yen as a deposit for the hotel reservation.
The deposit may not be refunded upon cancellation.
内金 is a partial payment or deposit on a purchase, broader than 予約金 which is tied to a reservation.
Compound of 予約 (reservation) + 金 (money).