prepay
To pay for something before you get or use it.
To prepay means to pay for something before you receive it or use it. When your family prepays for concert tickets online, you pay weeks before the actual show. When someone prepays their phone bill, they pay at the beginning of the month for service they'll use over the next thirty days.
The opposite is paying after you use something, like when a restaurant brings you the check at the end of your meal. With prepayment, the money goes the other direction first: you pay, then you get the product or service.
Many businesses offer prepayment options because it helps them plan ahead. A summer camp might ask families to prepay tuition in the spring. Some gas stations have prepay pumps where you pay inside before pumping gas. Prepaying can sometimes save you money too: a gym might charge less if you prepay for a whole year instead of paying month by month.
The word combines the prefix pre- (meaning “before”) with pay. Related words include prepaid (already paid for in advance, like a prepaid gift card) and prepayment (the act of paying early or the money paid in advance).