This article analyses the challenges associated with online auctions and consumer protection. Online auctions are increasing in popularity - however, they come with a range of potential legal issues. This article focuses on two potential concerns under the laws of both the United Kingdom and Australia: first, when an online auction fulfils the requirements of an auction for the purposes of consumer protection legislation; and second, when online auction sales occur "in trade or commerce". Both of these - apparently simplistic - questions highlight the complexity of the laws surrounding online auctions. Such complexity undermines the transparency of the legal system and puts consumers at risk of not understanding or appreciating their rights. The article concludes by making some initial points on potential reforms to improve transparency in the regulation of online auctions.