Under international law, children are treated differently from adults. They have comprehensive rights that recognise their developmental needs. But to access these rights, they must be identified as a child, which is why age determination matters. In response to alarming reports about the age determination procedures adopted by the Department of Immigration and Border Protection, we wrote a report into the age determination of asylum seekers in Australia. The information we gathered revealed serious gaps in the way age determinations were taking place, with repeated reports of determinations being made by inadequately qualified officials without reliance on substantive evidence.