Spirit customers can redeem frequent-flyer miles at the airline’s website. Frequent fliers can log in with their Free Spirit accounts to view the amount of miles required to purchase tickets for specific flights.
To search for flights purchasable with frequent-flyer miles, customers can select “Purchase with Miles” when they search for flights at the Spirit website. Free Spirit members can also switch between miles and regular pricing on the Flight Availability page.
Travelers can also book flights with frequent-flyer miles by calling the Spirit customer-service line and selecting option four to speak with a Spirit reservation agent. The airline charges an additional $25 fee for telephone reservations, as of 2015.