Check to see what dates are available. To use a complimentary ticket, you may need to book a minimum number of days in advance. For example, as of November 2010, India Air has a policy that the flight you book using a complimentary ticket must be at least 21 days later than the day of booking. For instance, if you book your flight Jan. 1, the actual flight cannot occur until Jan. 23 at the earliest.
Check to see to which locations you can fly. The most common restriction on complimentary tickets is the limit on where you can fly. Some airlines will only allow you to redeem a ticket to fly within the continental United States.
Check to see how long your complimentary ticket is valid. Certain travel vouchers and tickets are only valid for one year from the date they are issued.
Call your airline reservation number to redeem your complimentary ticket. The booking agent will know what your ticket allows you to do. It may be impossible to redeem a complimentary ticket online, depending on the airline's website.
