The Australian Prudential Regulation Authority issued this guide to assist Level 3 heads in complying with Prudential Standard 3PS 221 regarding the aggregation of external risks across their groups. The document mandates that boards establish comprehensive aggregate risk exposures policies, integrate exposure limits with risk appetite, and maintain robust data aggregation capabilities to support effective decision-making. It further requires accurate, timely risk reporting to the board at least quarterly, with increased frequency during stress periods, to ensure the group does not assume risks beyond its defined appetite.