Qantas has sunk its claws into the fat cats.

How? With a small change to the fare paying practices of the corporate travel firms that manage business accounts. It looks simple but it hurts.

Corporate agencies will now have to pay for domestic Qantas flights at the time of booking, rather than booking first and paying at the last possible moment, unless they are the full economy and full business class fares no responsible travel manager would contemplate buying in the first place.

So what you say, ordinary people who book and pay online at Qantas.com or on any other airline have always booked and paid at the same time.

Yes, but ordinary people get screwed by online booking practices every second of the day. This experience of raw pricing power and online fare manipulation is now being extended to the big end of town.

Until this change, travel management firms (like those serving banks, mining companies, telcos and other top 500 firms), have been able to do something the great unwashed can’t do: look inside the pre-internet but all powerful GDS or global distribution system to see exactly where the bargains are.

Ordinary schmucks don’t get full direct access to the GDS. It runs on protocols and key codes that are impenetrable to the point-and-click world of the consumer internet.

For example, a corporate firm might book a company employee on a flight for next Wednesday by GDS today and not make payment until Wednesday morning when its automated fare and availability checking program goes DING and spots a $99 seat on the same flight where full economy is $499.

So the corporate account server then matches last week’s booking to that morning’s super cheapie, which otherwise might have gone to a backpacker, and justifies its transaction or service fee to the client of say, $30, with a total net saving of $370.

Airlines around the world are insanely jealous of ‘downstream’ corporate travel managers getting between them and their most frequent and thus most valuable customers and, like Qantas this week, are changing the rules of engagement whenever possible to ensure that those most able to pay get kept away from deals aimed at fickle price sensitive and infrequent travellers.

Of course, a clever travel agent can still strike back by arbitraging the cost of cancelling an expensive booking and substituting the last minute deals that appear on agent-only GDS screens, but that is another area where every carrier is trying seal off all the escape routes from a full fare to a cheaper fare.