I recently bought a ticket from a (legit) European airline, with which I had flown before, for a national flight in an EU country.

In the process of booking, as I normally do, I tried to find the cheapest option and noticed something I did not think was possible. For the same exact flight, looking from two different tabs in my browser (one in which I was logged in to the airline system, one in which I was not), the price of the luggage option was significantly different (around 12 euros out of 25; the price of the flight was instead the same).

I know and understand that, in order to maximize profit, airlines use cookies and track customers to charge more when demand is higher. However, in this case what I can see is that two different customers (me and me, but the airline cannot know this since I am not logged in in one of the tabs) are shown two different prices for the same flight at the same time, and not depending on the demand for that specific flight.

I believe that in my case this happened as I had to book this exact flight for my parents first, and then book it for myself, yet I am still not sure if the airline is allowed to do this.

Therefore my question is: is it legal for an airline to show different prices for the same flight to different customers at the same exact time? Please note that I am explicitly referring to showing the prices at the same time, since I know that at different times of the day/week prices can be different.

P.S. I read this and this but I do not think they address my question. Moreover, I can say that after logging in from the browser tab where I was not logged in yet (I had to to make the purchase), the price shown was updated (and increased).

EDIT To clarify, the higher price was the one shown in the tab in which I was logged in. I had bought the ticket for my parents the day before, and my suspicion is that the airline increased the price because they "knew" I might be interested in that flight, given that I had already booked some seats, even though this time I was buying a ticket for another person.

  • @FreeMan no, I bought two tickets the previous day. Then, the other day I checked the fares for the same ticket and they were the same. I also checked the price for the luggage options, and this is what I noticed: if I checked it when logged in, the price was higher than when checking when I was not logged in. In both cases, I checked the price for the third ticket (and the luggage option, which is where the price changes) the day after I had bought the first two tickets.
    – DrMaga
    Commented Jul 7, 2022 at 18:04
  • Comments are not for extended discussion; this conversation has been moved to chat.
    – Willeke
    Commented Jul 7, 2022 at 19:01

5 Answers 5


is it legal for an airline to show different prices for the same flight to different customers at the same exact time?

Assuming the two people are offered the same fare class, this depends on the jurisdiction and the reason of the price difference. E.g., This article implies it is legal in the US to "raise prices because of browser cookies (targeted individually)". This other article echoes it. Other countries may have different policies, e.g. in China:

China's market regulator issued draft rules on Friday to punish illegal pricing activities, including heavy subsidies and the practice by online platforms of charging different prices based on customers' purchasing behaviour.

I don't know if that specific law passed, but you get the idea.

Pointers for EU regulations:

Related, on the hotel booking side, from https://millionmilesecrets.com/guides/are-airlines-raising-your-ticket-price-based-on-browser-history/:

The Wall Street Journal investigated claims that Orbitz, a popular online travel agency, was showing higher prices for hotel rooms to Mac users compared to those who used a Windows PC.

Orbitz later admitted that it was, in fact, a user trait that they were targeting. Mac users were able to purchase tickets at the same price as Windows users, but Mac users were also being shown more premium rooms, compared to Windows users who were always shown the cheapest price for a room first.

  • IIRC the Chinese regulations were made from a data protection angle so discriminations based on factors other than associated personal data would still be ok. Would GDPR require explicit consent to use behavioural data for pricing in EU?
    – xngtng
    Commented Jul 6, 2022 at 15:11
  • @Franck Dernoncourt thank you very much for your answer. Do you know where I can find this information for countries in the EU?
    – DrMaga
    Commented Jul 6, 2022 at 17:03
  • 1
    "showing higher prices for hotel rooms to Mac users" – That's a cool example of price discrimination! When I studied microeconomics, these techniques were never considered, but then again, eCommerce was still in its infancy and eBay and Amazon were only 4 and 5 years old. Commented Jul 9, 2022 at 10:16
  • @JörgWMittag kudos for being the first to use the proper economic term! Commented Jul 9, 2022 at 21:33

Of course it is legal. I can set whatever rules I like for the products I sell, including charging different prices for the same things sometimes. As long as I am not discriminating on illegal grounds (eg charging higher rent for an apartment to black people, or parents) I can do as I wish.

What's more, you can't be sure you're looking at the exact same ticket even if you're looking at the exact same flight. There are these things called fare classes. Even if the airline shows you big buckets (economy, economy+, business) they may actually represent a dozen or more fare classes. (To watch fare classes in action check the screenshots in this answer: Flight tickets: buy two weeks before even during holiday seasons? which prices the same flight over a period of time.)

Why would two tabs be shown two different fare classes? One reason is that tab #1 has "soft reserved" the last seat in a cheaper fare class, and so tab #2 is shown a seat from a higher class. Another, since you mention luggage fees and being logged in, is that your logged-in tab gets one free checked bag and your anonymous tab doesn't. There are various "they are all liars and cheaters" theories as well, but I don't subscribe to them and it's well covered in the linked questions. Yield management is complex to do and even more complex to understand from the outside without knowing what drives it.

But to return to your title question, yes, fare classes are legal. Just as a business class seat (on the exact same flight) can cost more than economy, just as a free-luggage-allowance-free-changes economy seat can cost more than a no-refunds-no-checked-bags economy seat, again on the exact same flight, so seats in two different fare classes with no visible (to you) differences can cost different prices. If you use a different tool to do your searches, or do the extra clicks to see the fare details, you may be able to see when this is what is happening.

On a practical level, sometimes if you let your first tab time out the soft reservation it had on that last cheaper seat also times out and your second tab can now buy it.

  • 5
    Isn't "I can [...] [charge] different prices for the same things [...] as long as I am not discriminating on illegal grounds" a tautology? Commented Jul 6, 2022 at 15:02
  • 22
    No. I can charge less on Thursdays. I can charge less when I have too much and it will spoil. I can give student discounts, seniors discounts, regular-customer discounts, whatever I want. I can randomly change the price throughout the day. Only if someone can show I charge based on a protected characteristic will governments get involved, and even then there are exemptions - various discounts and incentives are ok but eg a white-people discount would not be. Commented Jul 6, 2022 at 15:10
  • 14
    The point being there may be some circumstances in which different prices for the same thing are illegal, but in no way does that mean in general I cannot charge different prices for the same thing. And the larger point is that "The same flight" is not "the same thing" at all. Commented Jul 6, 2022 at 15:11
  • 3
    @KateGregory then you're moving a bit back into tautology land. "The airline can do whatever is not prohibited" is not a very useful answer for someone asking "is this specific practice prohibited in the EU".
    – mbrig
    Commented Jul 7, 2022 at 20:14
  • 4
    But that is not and was not the question. While there may be some restrictions, it is not a totally banned practice to have multiple prices at the same moment in time for seats on the same flight. It is also not proof of shenanigans or cheating that two browsers are shown multiple prices at the same moment in time for seats on the same flight. Some people try to rebut this by saying "but some things are disallowed" and that's true, but that wasn't the question. Some things are disallowed and some things are allowed and not all price variations are shady practices. Commented Jul 7, 2022 at 22:13

looking from two different tabs in my browser (one in which I was logged in to the airline system, one in which I was not)

but the airline cannot know this since I am not logged in in one of the tabs

Yeah, I figured a misplaced assumption may have been at the heart of this. That's not how cookies work.

A browser has only one repository of cookies shared by all tabs. Even if you reset your cookies, as soon as you logged in on the other tab, the airline now knows "that cookie is you".

You got different answers, however, because the two screens were giving data based on a different set of facts.

  • I suspect the non-logged-in screen is simply one you left up, and you did not refresh it. Thus, it was more stale than the screen from being logged in. Unbeknownst to you, facts may have changed in that time, such as another customer buying out the last low-cost luggage slot.

  • The non-logged-in screen may have presumed application of a new-customer discount. Same way my storage unit site will offer anonymous "me" a month for 99 cents, but after I log in, they want $250! It's a teaser deal for new customers, who I ain't. (I actively clear my cookies between sessions).

  • It's also possible the deals are not as equivalent as you think. There are a lot of details to a travel booking, and getting every single one the same for an A/B comparison is hard! So maybe the anonymous screen (if it is that) assumed one tier of luggage option, yet after you logged in it quoted you another tier since it knows you used it the last time.

  • 7
    "A browser has only one repository of cookies shared by all tabs" not to get into technical matters, but that's not true for, e.g., Firefox's container tabs.
    – MadHatter
    Commented Jul 7, 2022 at 6:24
  • 5
    OP stated they were using private tabs. Those have their own cookie jars.
    – jcaron
    Commented Jul 7, 2022 at 7:59
  • 1
    @Harper - Reinstate Monica thank you for your answer. You first point unfortunately cannot explain my case, since when using a third device (checking the price "at the same time") I kept seeing a less expensive option. The second point may be correct, however I would expect the airline to explicitly tell me they are giving the anonymous me a discount of some sort, which was not the case unfortunately. Regarding your third point, I double-checked everything and the two bookings were, at least from what I could see, identical.
    – DrMaga
    Commented Jul 7, 2022 at 17:57

In my experience, and given the way most booking systems work (especially those of the "traditional" airlines, which must be compatible with travel agents systems, the same price for the same service will always be presented to everyone in the same conditions.

A few things which can affect ticket prices:

  • Quotas ("buckets") for lower prices have filled up, so you have to book a higher fare.
  • Specific conditions for lower fares are no longer met: some fares are subject to "book X days in advance" conditions, for instance.
  • Likewise, if you're booking a return, if you change the return, that might change the pricing for the first flight as well (because of rules like "stay at least X days at the destination" or "stay the night from Saturday to Sunday"
  • Promotions have expired
  • You have a different frequent flyer profile, so you have different perks (like free or cheaper additional luggage...)
  • The same flight as an outbound or an inbound may be priced differently because pricing is usually done based on the country of origin of the first flight.

For the exact same full combination of flights (i.e. not just a single flight, but both outbound and return, or more in complex situations), in the same class, for the same date, at the same time, I would be surprised if there was actually any difference based on prior history.

Low cost airlines which only allow booking through their own systems may be able to pull off things like that, but I really doubt they do, things are already complex enough as they are.

For additional services, the chances different prices are given are even lower, as those are usually described in detail on the airline's website. However, again, there may be conditions like "price X up to Y days before departure, price Z after that", there may be different prices for flyers with status, or if the fare type is different, or if you are booking a return v. one-way and a lot more. But those are usually explained in much detail on the airline's website.


Unless you actually managed to load two browser tabs in a 1-2-1 succession and still saw a difference between 1 and 2 there's nothing iffy here. Instead you likely did load 1, browse at 2, reload 1 -- and it's now the same price as 2. If it were still lower that'd be beyond weird. Its just caught up. The price you saw on 1 before reloading is a mirage, it doesn't exist any more. If you tried to book , at the last screen where you actually need to pay you'd see a message of "the price has went up" or similar.

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