Background: Australia's four major airports: Sydney, Melbourne, Brisbane, and Perth are all privately owned and operated. While planes are the obvious business, airports also make money from retail, property, and a big cash generator - car parks.  

What happened: The ACCC's latest airport monitoring report for the 2025 financial year shows the four airports made a combined $402 million in operating profit from car parking alone. Brisbane Airport led the pack with $125 million in profit, earning 77 cents of profit for every dollar charged.

What else: Sydney Airport generated 66.3 cents profit per dollar, while Perth and Melbourne earned 61.4 cents and 59.5 cents respectively. The numbers highlight just how significant the airport parking revenue stream has become. And how nobody can stop these airports in their natural monopoly.

What's the key learning

💡A natural monopoly is a monopoly in an industry where high infrastructure costs give the largest (and often only) supplier an overwhelming advantage over potential competitors.

💡 Airport infrastructure is so expensive to build that it only makes sense for one provider in a location - and this gives operators significant pricing power. Car parking might feel like a side business, but it's highly profitable. the four airports earn 8% to 14% of total revenue from parking.

💡 Right now, airport charges aren't regulated and the ACCC has consistently raised concerns that the current monitoring framework is inadequate. So despite the current monitoring by the ACCC, it may not be enough to keep pricing in check.