This paper focuses on two countries with debt-funded ownership-centred housing systems, Australia and the UK. Financially, there are similarities between these two societies, which have relatively ‘complete’, reasonably well-regulated mortgage markets, had limited exposure to the extremes of subprime, and have been pre-occupied with (and reasonably successful in) restoring ‘business as usual’ in housing and mortgage markets. Institutionally, however, the countries differ from each other, notably with respect to the size and function of the rented sectors. By modelling matched datasets from panel surveys in Australia and the UK, this paper considers how home-buying households in these financially similar, institutionally distinct, countries coped with the ups and downs of housing and mortgage markets in the first decade of the millennium. To address this, we focus on the edges of ownership: that once-stark boundary between owning and renting whose character is often taken for granted, yet which contains important signals about the functioning of housing systems, their link to the wider economy and the well-being of home occupiers. The analysis considers in hitherto unprecedented empirical detail how, why, when, for whom and in what way the edges of ownership proved precarious in the decade to 2010.