This Discussion Paper, issued by the International Auditing and Assurance Standards Board (IAASB)’s Agreed-Upon Procedures (AUP) Working Group, sets out the key features of an AUP engagement and explores how they are undertaken, including the extent to which practitioners find existing requirements and guidance helpful or challenging. In addition, the IAASB is seeking an understanding of how reports on factual findings are used to determine the needs of users.