Can I buy extra miles on a lease?

Yes, most lessors let you choose a higher mileage allowance at signing, which raises the monthly payment slightly but usually costs less per mile than overage charges at the end. Some also let you buy additional miles during the lease. If you underestimate, ask your lessor about options before the lease ends. If you overestimate, unused miles generally aren't refunded, though some lessors offer credit, so estimate carefully.