Yes, overbooking flights is legal in Australia and is a common industry practice among major carriers like Qantas, Virgin Australia, and Jetstar. Airlines use sophisticated algorithms to estimate the "no-show" rate for each flight, selling more seats than the aircraft can hold to maximize revenue and keep ticket prices competitive. Unlike the United States or the European Union, Australia does not have specific federal laws that mandate a fixed cash compensation amount for passengers who are "bumped" from an overbooked flight. Instead, these situations are governed by general Australian Consumer Law and the airline's own "Conditions of Carriage." Typically, if you are bumped, the airline will offer a seat on the next available flight and may provide meal vouchers or hotel accommodation if the wait is overnight. While some airlines might offer an "expirable" travel voucher as a gesture of goodwill, they are not legally required to provide the high-dollar cash payouts seen in other regions unless you can prove a "consequential loss."