Check with your airline or credit card to determine whether or not your terms and conditions allow you to redeem miles for a companion ticket. To use your frequent flyer miles for a companion ticket you usually have to be booked on the same flight as your companion.
Visit the website of the airline that accepts your frequent flyer miles. Log in to your account and choose the "Use Miles" link to begin using your miles.
Enter your departure and arrival cities, the dates you wish to depart and return, and the number of passengers.
Review the list of available flights for your travel dates and choose the ones you want. Your airline will then calculate the total number of points used to purchase the ticket. You will be asked to confirm your purchase.
Print your confirmation page for your records.
