Why do all airlines require you to distinguish your first name and last name?

Contrary to popular belief, names (even Western names) are not self explanatory.

Compare Tucker Carlson vs. John Oliver. No, not for their respective TV programs but they actually have middle names:

• Tucker Swanson McNear Carlson
  To me that looks like four family names! Two of which I would consider to be Nordic (-son) and a Scottish one. What if a Mr. McNear married a Ms. Carlson and they kept both names for "McNear-Carlson" naming their son "Tucker Swanson"? Then it would only be three names and a missing hyphen.
• John William Oliver
  That’s three given names! Plus, they are extremely common given names. I’m wondering why they didn’t put a Harry in there, for good measure. How do you keep that apart from Oliver Peter John (who is a psychology professor at Berkeley, as my favorite search engine tells me), if both choose to not give their middle name?

Now try to find those names, e.g. on a no-fly list. And for shits and giggles don’t let anyone fly whose name is Muhammad Ali (Wikipedia lists 11 celebrities, including 3 different boxers), because one of hundreds of thousands of non-celebrities with that name is listed as no-fly. Do you also want to deny all Ali Mohammads, too?

Names matter and it’s bad enough with common names, no need to add more confusion by not properly distinguishing the structure.

While other answers attempt to justify this requirement, and I agree that a system written from scratch today, might make that distinction based on English-speaking norms. However, I think there is a much more important reason it exists in this scenario: because decisions made decades ago are now hard to change.

Much of the travel industry, and particularly traditional "scheduled" airlines, is run on computer systems which ultimately date from the 1960s. Parts of them have of course evolved and been replaced since then, but each new system needs to be compatible with the last, and with other systems still running, so changing fundamental design decisions is difficult.

In particular, reservation details are stored in something called a "Passenger Name Record", or "PNR". Although not fully standardised, these are used throughout the industry, and frequently need to be exchanged between systems without loss of data.

In a PNR, names are represented as a separate first name and last name, traditionally entered and displayed as SURNAME/FIRSTNAME. (Oddly, there is not generally a separate field for the title / honorific, leading to confusing conventions and incorrect display.)

So, the systems want your first name and last name because their system has those fields; and the system has those fields at least in part because its predecessor 60 years ago had those fields.

Because the name on the machine readable section of your passport is given in a specified order and it needs to match.

There are times the system will need to interact with other systems. At which point things needs to be standardized. If that system wants the first name and last name as separate fields then the airline needs to send them as separate fields.

I recently had this problem where the airline had my first name and last name, while my covid documents had first, middle, and last name. Whatever automated system the airline was using to validate my covid documents thought I was a different person. Minor annoyance in the grand scheme of things but I can imagine there are plenty of legacy systems running bits of code which require things to be in some exact order and no one is brave enough to change the code.

In the US, practically every organization that collects names of members, customers, participants, etc. asks for first and last names separately. As others have said, this makes it easier to produce formal and familiar greetings:

Hi, Joseph

Greetings, Mr. Smith

In my experience, at least 90% of web sites and paper forms have separate fields for first and last names (and sometimes also ask for the middle initial and/or suffixes like "Jr."). Forms that are intended to cater better to foreigners may designate these as personal name and family name/surname, since some cultures reverse the order (in Chinese, family names come first).

In addition, if the organization needs to look you up in other databases, being more precise about the name will generally make it easier to correlate them.

Why should airlines be any different?

In many societies (but not all), people have one or more given names, and one or more family names.

If you want to identify a person relatively precisely, you want as much of those as possible, at least to hopefully differentiate different people in the same family (even though that often fails miserably — I can tell you that from first hand experience, as I share the same first and last names with my father and my late grandfather).

On the other hand, it is common in many societies (but again, not all) to address people formally by using only their surname and a title (and to use only the first name in more familiar address).

Programmers and the people around them have long made arbitrary decisions on how names work so they can derive these various forms easily. For that purpose, they need to know which part of the full name is the last name.

For instance, if your name is Michel Martin, knowing that Michel is your first name and Martin is your last name and that your title is Mr, one can:

• Derive a formal form of address: "Mr Martin"
• Still have a more complete form of your name for ID matching and the like.

If you didn’t know which one is which, you could end up saying "Mr Michel", which isn’t correct. And that’s of course the simplest case.

Quick anecdote: a few decades ago, when you could take a plane like you would a bus, I arrived at the counter at LAX and asked for a ticket for the first flight to SFO. The agent just asked for my credit card, and took my name from the card to issue the ticket. But it was a french card, and in France, in certain circumstances, you place the last name first, and that was the case on my card (and still is on one of my cards, but not on any of the others!). So I ended up with a ticket for JACQUES/CMR.

Having separately fields for given name and surname works most of the time for people from some Western societies, though even in that context it sometimes fails completely. As soon as you stray outside those areas, it is often catastrophic, but still, there is no easy way to achieve the intended result without this distinction. The alternative would be to ask for full name (for identity) and "form of address", but 90% of people wouldn’t even understand the question, and many would think the system is dumb if it can’t just guess it from their name…

Another issue is also that "name" or "full name" are very vague terms. If you just say "please enter your name", you don’t know if people will enter just their surname, just their first name, or both (not even straying in the territory of additional given names, suffixes, aliases, etc.).

Asking for "given name" and "surname" (or variations thereof) separately at least gives a strong hint to users that they should enter both. Of course that fails for people who only have a single name, and even with those hints, people can easily get confused (especially if you use "first name" and "last name", as the order of writing surnames and given names is not the same everywhere).

Add to that that airline systems are often interconnected with other systems, many of which have been defined decades ago, which require the information to be split this way, and this is not going to change any time soon.

If you have a name like Wang Yang in English, that should be identified with someone named Wang, Yang not some other dude named Yang, Wang.

Since it’s usual in Asia to write family name first, and the opposite is usual in the West, and sometimes people swap their names around for various reasons, it’s better for all concerned to keep things straight. Especially when it comes to computers and databases.