As with anything in airline pricing, surcharges are a complicated business. I don't know if this is a great place to explain some of it, but here I go...
I will say up front that I understand the mechanics of how this stuff works much better than I understand the business rationale behind it or the history of how it got this way.
Most of the complication is caused by interlining. There are four (!) different basic ways that an airline can be involved in a ticket:
- As ticketing carrier (sometimes called "validating" or "plating" carrier). In the end, a ticket must be issued by a single airline, on that airline's virtual (or physical paper) ticket "stock". This airline gets the money and distributes it to the other airlines on the ticket.
- As fare owning carrier. This is the airline whose fare is used and who sets the price for the flights the fare covers.
- As marketing carrier of a flight. This is the airline whose flight number is used; they're the ones offering the flight for sale.
- As operating carrier of a flight, the ones who own and operate the plane and supply the crew.
For example, Lufthansa (1) might sell a ticket that contains an Air Canada (2) fare which pays for a United (3) codeshare flight operated by US Airways (4). The ticket might (or might not!) also have some Lufthansa fares and flights on it. Because of the Air Canada fare, there will definitely be some Air Canada marketed flights in addition to the United marketed ones.
Of course, most tickets are not nearly so complicated. In fact, most tickets probably have the same airline doing all four things.
One kind of fuel surcharge has existed for a very long time, well over a decade. It is part of the fare, and it appears as part of the fare rules under a section called "surcharges", and in the fare calculation line after the letter "Q". Because it's part of the fare, only the fare owning carrier can say anything about how much is charged - they file it as part of the fare rules. There's no question about it being considered a tax - it's part of the fare amount, and other taxes apply to it as such.
Some time much later, after 9/11, a new kind of fuel surcharge was introduced, labelled "YQ" or "YR" (these are tax codes that IATA reserved for carrier internal use). This is a surcharge that is imposed by the marketing carrier of a flight, and is published separately from the fare rules (marketing carrier XX doesn't have any say about the fares of carrier ZZ that might nonetheless pay for XX's flights). There's a catch, though - the validating carrier must agree (concur) to collect the fee. If they don't agree, then the fee is not due on the ticket.
These new surcharges often appear on the ticket as if they were a tax. Historically, there's really only two places it could go - as part of the fare or as a tax - and it would take a huge amount of software development in dozens of systems out there to have it appear in a new category. And for interline purposes, the protocols used to communicate between those systems would also have to be agreed upon and upgraded.
Because the (generally bilateral) agreements between the airlines usually only spell out how the
fare amounts get divided up between the airlines on a ticket, as I understand it, the validating carrier will generally keep any of these YQ/YR fees that are collected. So although the marketing carrier decides how much to charge for these YQ/YR surcharges, the validating carrier gets to decide whether to charge it, and if they decide to do so will generally keep the money.
One dirty little secret of the industry that follows from the above: if you can find a non-concurring carrier to act as validating carrier (and it doesn't necessarily have to be a carrier that otherwise appears on the ticket!), you can get out of paying all of these new fuel surcharges. Because the fraction of the ticket due to these surcharges has been growing over time, this can sometimes lead to a very substantial discount!
In theory any travel agent can override the validating carrier in their GDS, and a judicious choice will produce an (automatic) pricing that leaves out the surcharges. And they wouldn't be breaking any rules by doing so. In practice most agencies are afraid of damaging their good will with the airlines, so they are unwilling to do these overrides. Sometimes you can find a carrier whose website will sell tickets completely on other carriers, and get around the surcharges that way (without naming names, there have been recent examples posted on FT).