If you have a confirmed reservation, you are indeed confirmed on the flight -- even if the airline`s computer system says there is no record of your reservation. An agent cannot deny you a chance to board your flight if you have your ticket or a confirmed reservation print-out (unless you canceled the reservation either by actively initiating the cancellation or missing a confirmation deadline). If the day of the flight comes and goes without you in the seat, and you didn`t cancel your reservation, the airline will note you as a `no-show` and will cancel the rest of your itinerary.

Remember these general rules, which tend to be the same across carriers, although the full list of refund guidelines will vary depending on the airline used for the journey. If you have to cancel a ticket classified as a non-refundable fare, you might be allowed to apply the cost of the fare to a future flight, after cancellation fees and price changes are taken into account. If your ticket is refundable and you must cancel it for whatever reason, the refund will be processed and credited to the same credit card used to reserve the tickets.

It`s important to know that an airline can cancel your reservation if you are not present at the departure gate at the time of boarding, even if you`ve already checked in online or at the airport. Your seat may be given to someone else even if you arrive with enough time to spare to reach the gate before your flight leaves.

Also, if you do not check your bags in with enough time for them to be loaded onto the plane, the airline cannot be held responsible for the delay in your baggage arriving at your destination. Even if you have already checked in for your flight, an airline can cancel your reservation if you are not at the departure gate on time. Arrive at least two hours before your departure (earlier if you are flying at peak tourist season, during holidays, or internationally).

All travelers over the age of 18 must present photo identification when checking in and boarding the aircraft. (Many minors do not have to present identification for domestic travel, but the rule varies by airline, so try to bring identification if possible.) Make sure the name on your identification matches the name on the ticket exactly.

Each carrier`s rules are different, but it is important to know that airlines do not have to compensate travelers if their flights are delayed or canceled. Most airlines will book you on the next available flight. With delayed flights, airlines may pay for meals or a hotel; this may not be publicized, so asking may be the key to getting. The only times airlines are required by U.S. law to compensate you is if you were `bumped` off an oversold flight.

You do have the right to compensation if you are traveling in the European Union and your flight is canceled or delayed -- but only under specific circumstances, aka `extraordinary circumstances which could not have been avoided even if all reasonable measures had been taken`. This means you are out of luck if security, weather, political rallies, strikes, etc. delay or cancel your flight. Visit the European Union`s website for more information regarding cancellations and compensation.

There are no federal requirements that govern delay times while passengers are waiting in the airport terminal, but there are indeed requirements which limit how long travelers can sit on the airplane while awaiting takeoff. No plane must be kept on the tarmac for more than three hours and if any plane passes the two-hour mark, drinking water and some sort of food option must be provided to passengers. The bathrooms must be functional while the plane is on the tarmac. If security is at stake, either inside the airport or as a result of the aircraft returning to the gate, the three-hour requirement can be waived. The longest delay an international flight on the tarmac can endure is a wait of four hours. If airlines do not comply with these regulations, they can face fines.

To account for no-shows, airlines can, and often do, oversell flights (meaning they sell tickets to more people than can fit on the aircraft). If, in the event that every ticketholder shows up for the plane, some passengers will be asked to give up their seats, to be placed on a later flight. Those who agree to be moved to a later flight may receive perks such as future airline travel vouchers, accommodation vouchers, and cash money. These perks are negotiated with the airline before and after exiting the aircraft.

In the event that you are `bumped` -- aka involuntarily taken off an oversold flight -- the airline will explain your passenger rights in a written document. You will be allowed to keep your ticket to use on another flight to the same destination. You can be refunded for the price of the ticket (an `involuntary refund`) if you decide to make your own arrangements to get to your destination. The carrier does not have to compensate you if they can prove they can get you to your destination airport within an hour of the original aircraft. If a plane is swapped out for a smaller one, thus pushing a number of people off the scheduled flight, airlines do not have to compensate passengers in this event.

File a claim with your airline at the airport the moment you find that your baggage has not arrived like it`s supposed to. Airlines will typically agree to compensate `reasonably` until the luggage is found. This amount is negotiable and it may take some finesse on your part to get your fair share.

A second claim will be needed if your bags are not found. This claim will take a while to process (weeks or even months). In the U.S., airlines are limited to paying out $3,500 per person in the event of lost or stolen luggage. The liability limit may vary on international flights due to the terms set forth by the Montreal Conventions. The airline must refund the baggage fee if the bag ends up lost or stolen. Every check-in deadline must be met throughout the booking and boarding process, or you will find the airline isn`t responsible for the bag or the value of the items inside.

If bags arrive with you, but they (or its contents) are damaged, airlines may be able to compensate you. Fragile items may be excluded, as will heirlooms, money, and other important items that should have been packed in your carry-on.

Your rights may be referred to on the airline websites as the `Conditions of Carriage`, or the `Contract of Carriage`. You may have trouble finding it, but each airline is legally obligated to post such a statement somewhere on their website. If you want to know what you are entitled to as a paying customer, and what you`re not entitled to, these rights statements will spell everything out for you.

According to the Department of Transportation and the Air Carrier Access Act, disabled passengers may not be denied the right to board an aircraft on the basis of their disability, nor must they have an attendant or medical documentation unless the circumstances are particularly unique. Also, airlines must provide free of charge:

1. Help with getting on and off planes and making connections, whether this means a wheelchair, a person, both, or other means

2. TTY devices in airport terminals and airline reservation centers

3. `Timely access` for any visually or hearing-impaired passengers to information on gate assignments, security and other publicly announced information

4. Access to the plane`s cabin for any necessary service animals (as long as they don`t block aisles or escape routes)

5. Permission to include wheelchairs as checked baggage without liability waivers (except for pre-existing damage)

The most important thing to remember is that an airline isn`t necessarily indebted to you in the event of a flight delay or cancellation. Bad weather, `acts of God` (extraordinary circumstances outside the airline`s control) and other factors may absolve the airline of responsbility. In many events, the airlines may refund your ticket (even if it is bought under a `non-refundable fare`), but will not take responsibility of your journey after that.

The following is a partial list of situations in which an airline may legally deny you boarding or remove you from a flight on which you are confirmed.

1. If the airline must comply with any government regulation or request for emergency transportation in connection with national defense.

2. If there is inclement weather or other conditions beyond the airline`s control.

3. If you refuse to be searched for explosives or concealed weapons.

4. If you refuse to provide positive identification or don`t have proper documentation for travel across international boundaries.

5. If your conduct is disorderly, abusive or violent, or if you are under the influence of drugs or alcohol.

6. If you are barefoot or clothed in a way that might be offensive to others.

7. If you attempt to interfere with any member of the flight crew or jeopardize the safety of the plane.

Call or write the airline`s consumer office if you cannot resolve your problem while at the airport. Reaching out via social media (Facebook, Twitter, etc.) also helps to obtain a speedy response.

The DOT has a website set up specifically to deal with consumer complaints; you can submit an online form (www.transportation.gov/airconsumer/file-consumer-complaint) or find the agency`s phone number and mailing address.