Airlines sometimes sell more tickets than there are actual seats on a plane. This is a standard part of airline operations, especially during peak travel seasons. In such cases, unlucky passengers may find themselves without a seat on their flight. This situation is commonly referred to as "bumping".

What should passengers do if they find themselves in this situation? Here's what you need to know and how to respond.

Avoid late check-in if you don't want to be 'left behind'. *Photo: T+L*

Is airline overbooking legal?

It is entirely legal for airlines to overbook flights. According to Jesse Neugarten, founder of Dollar Flight Club, a cheap flight notification service, airlines do this "all the time". He explained: "Airlines are permitted to sell more tickets than available seats because they rely on historical data regarding the percentage of passengers who miss their flights or fail to check in. Consider it a probability calculation. Most cases are fine, but occasionally, no-shows don't happen, resulting in some passengers being unable to fly."

Who is most likely to be 'bumped' from a flight?

If no one volunteers to give up their seat, airlines follow specific criteria to decide who stays behind. This process is not random. Neugarten explained: "Passengers who check in late, book basic economy fares, or do not have an assigned seat are often put on the 'bumping' list. Solo travelers are also easily chosen because the airline can more readily arrange an alternative flight for them." Conversely, he noted that if you have elite status, purchase a higher-priced ticket, or check in early, your chances of being left behind are very low.

What to do if you are denied boarding?

If you find yourself in this situation, do not panic. Stay calm and remain at the departure gate area. Neugarten advises passengers to request a written explanation (or any documentation) from staff, as the airline is obligated to provide this. Afterward, check the airline's application for alternative flights. He stated: "In many cases, passengers can rebook their tickets on the app faster than waiting in line."

Passengers should also inquire with staff about compensation and what assistance they can offer to help you reach your destination, such as a seat on the next available flight, meal vouchers, or hotel accommodation if your flight is delayed overnight.

Neugarten advises anyone who is "bumped" to speak up. He said: "You have more power than you think. Remember, being bumped does not mean you have to continue flying with the same airline. You should ask if they can arrange for you to fly with a different airline. Many ground staff can do that, but they won't unless you ask."

Furthermore, if your new flight arrives more than one hour later than your original flight, you may be entitled to cash compensation. Specifically, for flights delayed by one to two hours (domestic) or one to 4 hours (international), passengers have the right to receive 200% of the one-way fare. If the flight is delayed by over two hours (domestic) or 4 hours (international), passengers have the right to receive 400% of the one-way fare.

It is important to note that this compensation applies only to passengers involuntarily denied boarding. If you are asked to voluntarily give up your seat, you can (and should) negotiate. Request cash instead of vouchers, and do not hesitate to ask for meal or hotel assistance.

Why demand cash? Vouchers can expire, have blackout dates, or come with complex conditions. Finally, Neugarten emphasized, always request written confirmation of any agreement.

How to avoid being 'bumped' from your flight:

- Check in early: This is the simplest method. The earlier you check in, the lower your chance of losing your seat.

- Select seats in advance: Having a specific seat assigned on your ticket helps the airline identify your spot as "confirmed". However, this does not provide a 100% guarantee.

- Fly during off-peak hours: Holidays or weekends are often crowded. If your schedule allows, choose to fly mid-week or early morning.

- Be loyal to one airline: Frequent flyers with elite status are rarely "invited" to stay behind.

- Book a higher fare class: Basic economy tickets are always at the bottom of the priority list. If you need to ensure you arrive on time, pay a little extra for a standard economy ticket.

Tam Anh (according to Travel + Leisure)