The first step in using miles is to join an airline program that gives upgrade rewards. Sign up with an airline you use regularly or look into a credit card program that rewards its customers with flier miles on purchases.
Be sure to read all the guidelines before you start to accrue flier miles to make sure all flights are eligible with each booking.
Before you book your ticket, check to see how many flier miles you have been rewarded. This can be done by logging into your account online or by contacting airline customer service.
Take note of when frequent flier miles expire. Airlines put an expiration date on frequent flier miles, so it's a good idea to always know when you need to use them before it's too late. In some cases, you can reactivate expired miles, but airlines charge a fee for this service.
Read the small print. Once you have your flight booked, make sure it is eligible for a first-class upgrade using your frequent flier miles. You can either check the conditions of your ticket online or contact the airline's customer service center to find out this information.
Upgrade online or contact the airline's customer service. Check your ticket online to see if the airline permits you to upgrade it using their website. Alternatively, you can contact an airline customer service representative to do the upgrading for you. Note that you may be charged a fee if you don't use the internet to upgrade. For example, as of November 2010, American Airlines charges $20 for AAdvantage Award customers who use their reservation center and $30 for those who upgrade at travel centers or the airport.
