I am an aerophobe, so flying is never a pleasure. But my latest trip brought an unwelcome surprise before I had even left the ground. Let me tell you how it went:

I had tried to check in online, but the app wouldn't let me. So I arrived at the airport more than two hours early to check in manually. Nothing unusual, right? Until I reached the desk and was told the flight was overbooked and I might not fly that day. “Wait until check-in closes,” the woman said. “If some passengers are late, you may get on.” My protests were met with the same reply: “I can’t help.” So there I was: early, paid up, ticket in hand, and still not guaranteed a seat.

Spoiler: no tears were needed. In the end, I flew home, thanks, ironically, to Moscow’s traffic jams, which held up other passengers on their way to the airport. But the shock lingered, and so did the questions. Had the system chosen me, or was I simply too late? What are my rights if I am stranded? Can I claim compensation for the stress this causes? And why does overbooking still exist?

Thank you for the inspiration, dear airline. Here we go.

Picture this: you buy a ticket on the airline’s official website, pay the full price and pack your bags. Then you are told there is no seat for you. No storm, no technical fault, just more tickets sold than there are seats available. So why is this legal?

First, we need to understand why airlines do it in the first place. And it is proof that someone finally found a practical use for all those maths and statistics lessons. Airlines have turned human unpredictability into a mathematical formula. Statistically, passengers are wonderfully predictable: a fair share of them never turn up. One academic paper, Voluntary Overbooking in Commercial Airline Reservations, citing earlier research, puts no-shows at 10–15% of bookings. Missed connections, last-minute changes of plan and plain old oversleeping all leave seats empty. For an airline, an empty seat on a departing plane is money gone for good. So airlines crunch years of data, predict how many passengers won't show up and sell a few extra tickets to fill the gap.

So how can a business legally sell more tickets than it has seats? Because overbooking isn't a hidden trick or a violation of the rules. It is part of the airline's terms and conditions, which passengers agree to when purchasing a ticket. And these terms operate within aviation regulations. While there is no single international rule, the United States, the European Union and the UAE each have their own frameworks, setting out what airlines must do if more passengers turn up than there are seats available, including alternative travel, assistance and compensation where applicable.

The standard line airlines use when faced with criticism over overbooking is that it helps keep fares affordable for everyone. But is that actually true, or just a convenient excuse?

Take a plane with 180 seats. The airline knows from experience that around five passengers won’t turn up, so it sells 185 tickets instead. At 200$ each, that is up to 1,000$ in extra revenue on a flight that costs almost exactly the same to run. In theory, that bonus could be passed on to passengers through lower fares. In practice, it could just as easily slide quietly into the airline’s pocket. And who would ever notice?

To be fair, there is some support for the airlines’ argument. A 2019 report by the US Government Accountability Office cites revenue-management experts who suggest that without overbooking, airlines would offer fewer discounted tickets.

But there is a difference between suggesting that fares could be lower and proving how much passengers actually save. Neither the report nor the experts cited provide a figure for that. So cheaper tickets may well be part of the bargain. How much do we actually benefit? We simply don’t know.

Back to my story. Once check-in had closed, I returned to the counter, only to discover I wasn't alone. Seven other passengers were in exactly the same situation. And, surprisingly, they all looked rather like me.

That got me thinking about something I probably wouldn't have questioned otherwise: is overbooking really just a matter of bad luck, or are certain passengers deliberately selected? The answer came pretty quickly: yes, airlines have specific criteria for deciding who gets left behind when there aren't enough volunteers. And they don't exactly hide it.

Some factors are fairly predictable. Passengers travelling on cheaper fares may have lower priority, while frequent flyers with higher loyalty status are more likely to keep their seats. Even the time you check in can make a difference (so that advice about arriving early isn't entirely pointless)

But there are other, rather more questionable factors worth exploring:

First things first: don't panic. Like it or not, airlines are legally allowed to overbook flights. But that doesn't mean you have to quietly accept whatever they offer. A few things are worth knowing.

In my case, I eventually got on the original flight. But what about the nerves and the hours spent wondering whether I had make it home?

Unfortunately, if you do end up flying as planned, you generally won't qualify for denied-boarding compensation. And while the stress is very real, it doesn't automatically entitle you to a payout either. You can always ask the airline for a goodwill gesture, though. As for me, I did receive an email saying “sorry”. So there is that.