Frequent flyer programs allow you to earn certain travel benefits based on the number of miles (or occasionally the number of trips) you fly on a particular airline. Typical awards include a free ticket or a free upgrade from coach to first class. Some airlines also offer "elite" programs which provide check-in and boarding priorities, and "affinity" credit cards which earn mileage credits when you use them for purchases.

In order to earn these benefits you must become a member of that airline's program; this can often be done through a travel agency. There is no limit to the number of programs you may join. Before deciding which program(s) to join, compare them carefully. You don't want to get "hooked" on one program by accumulating a high mileage balance, only to learn that another program offers superior benefits for your particular situation. In making your decision you should consider:

- the rate at which credits are earned,

- minimum credits earned per flight (e.g. you are only going 200 miles but the airline always credits at least 500)

- whether you are most interested in free tickets for yourself, "companion tickets," or upgrades,

- how much credit is needed for the awards you are interested in,

- deadlines for using accumulated credits (e.g., in some programs miles expire after three years),

- whether the airline serves the cities you would like to travel to, and whether it has tie-ins to other airlines (especially foreign carriers) and to hotels and car rental companies you would use,

- whether awards are transferable or for the member's use only.

Each airline's program carries certain conditions and limitations. You should carefully read the promotional material and the "fine print" booklet that the airline should give you when you become a member. Also, pay attention to notices that you receive in the mail after you enroll; they sometimes describe changes in the program.

Here are some other important considerations to keep in mind when comparing frequent flyer programs:

Airlines reserve the right to make changes, often on short notice. This can include changes to the conditions and limitations and also to the awards and the rate at which awards are earned.

Keep track of the mileage you have earned, and check it against the statement that the airline mails you. Keep your boarding pass and the "passenger coupon" portion of your ticket

If the airline adds a new route after you enroll, especially an international one, you may be able to earn mileage on that route but not use awards there.

Don't plan to use an award immediately after earning enough credit for it. The airline needs time to credit the most recent mileage and then issue an award certificate or ticket.

Availability of space on flights for frequent flyers is often treated in the same manner with many of the same conditions as deeply discounted air fares. This could include advance reservation requirements, blackout periods (generally during peak travel times, including holidays), length-of-stay limits, and limits on the number of frequent flyer seats on many flights (to as few as zero on some flights).

If your award flight is canceled or greatly delayed, can you travel on another airline? If your own plans change after an award ticket is issued, can the ticket be used on another flight, or can the trip be canceled and the mileage re-credited to your account?

One special reminder: airlines often restrict the transferability of mileage earnings.

Almost without exception, the sale (or even attempted sale) of credits or awards violates the provisions of the program and may result in the revocation of all accumulated mileage and/or termination of your participation in the program. However, awards can usually be given to others as gifts.

Persons who buy coupons also run a risk. If the airline suspects that the bearer of a coupon or ticket is not the party designated to use the travel document, the airline may refuse to honor it and may even confiscate it. In such cases, the airline invariably disclaims any obligation to the bearer of the coupon or ticket; the purchaser's recourse, if any, would be with the seller of the travel document.

The Department of Transportation does not regulate airline frequent flyer programs. These are matters of individual company policy. If you are dissatisfied with the way a program is administered, changes which may take place, or the basic terms of the agreement, you should complain directly to the company. If such informal efforts to resolve the problem are unsuccessful, you may wish to consider legal action through the appropriate civil court.