It’s a situation many business travelers have encountered before: Your flight is overbooked to compensate for a number of no-shows, but when all passengers check in on time, the airline must scramble to figure out an alternative solution.

Usually, airline carriers offer some sort of voucher, perhaps a free trip in the future, to travelers who voluntarily give up their seat. But when there are no takers, the airline has to decide who will not get to fly on that scheduled flight.

So what rights do you have when an airline must bump flyers involuntarily? And what can you do to try to avoid getting bumped yourself?

These are questions on many business travelers and travel managers’ minds.

And as Henrik Zillmer, CEO of the passenger assistance site, explained to, ”There will be much more of this (overbooking of flights) in the future, so people really need to know what to do and what they’re entitled to.”

What’s the U.S. law?

It is not illegal for airline carriers to oversell a flight. In fact, it’s a standard practice among airlines in order to account for no-show passengers or those who arrive late. And airlines actually have a lot of leeway if and when it comes to the point where it needs to deny passenger(s) entry on an aircraft.

As Scott McCartney wrote in a recent “Middle Seat” column in the Wall Street Journal, “An airline ticket is really a contract that the airline will transport you from one city to another. You actually haven’t purchased a specific flight or a specific seat; the airline can change all that on you.”

Passengers are required by federal law to comply with crew instructions. So even if you already are on the plane, if you are asked to leave, the law is on the airlines’ side and you must comply.

How to avoid getting bumped from a flight

So what can you do to avoid getting bumped?

If possible, check in online before arriving at the airport and nail down your seat assignment since some airlines will consider check-in time when deciding who gets bumped. Also, don’t dillydally in the airport’s duty-free shops and get to your gate promptly — at least 30 minutes before the scheduled departure time — since latecomers are more likely to be denied from boarding an overbooked flight.

It also helps to be a member of the airline’s loyalty program since the company wants to please, not irk, their most valuable customers. Those flying in first or business class also are less likely to get bounced from these pricier seats.

What to do if you do get bumped

As the U.S. Department of Transportation (DOT) states on its website, it “requires each airline to give all passengers who are bumped involuntarily a written statement describing their rights and explaining how the carrier decides who gets on an oversold flight and who doesn’t.”

Carriers must get passengers who are involuntarily bumped to their final destination within one hour of their originally scheduled flight — or begin forking over money.

As the DOT outlines on its website, if the airline delivers the involuntarily bumped flyer to the destination between one and two hours domestically or one and four hours on international flights, the airline owes you 200 percent of your one-way fare, up to $675. If it is more than two hours on domestic flights and four hours on international flights, then the amount spikes to 400 percent of your one-way fare, up to $1,350 maximum.

Like with any set of rules, there are a few exceptions. For instance, you may not be eligible for compensation if you do not have a confirmed reservation within the airline’s system or if you are not at the gate 10 to 30 minutes before the scheduled departure time. To read the full terms and conditions, visit the DOT’s website.

The European Commission also has its own rules when a passenger is denied boarding a flight in EU countries, which you can read about here.

Customers enrolled in American Express Global Business Travel’s Proactive Traveler Care service: If you ever find yourself in this position, be sure to use the tap-to-call function on the Amex GBT Mobile App to speak to a travel counselor who can help rebook your flight seamlessly.