The corporate reporting landscape has evolved in the last 20 years from financial reporting to sustainability reporting to “integrated reporting.” The corporate reporting history abounds with different attempts at integrating sustainability accounting with financial accounting (e.g., the Corporate Report 1975 and the “Triple Bottom Line” concept) and thereby attempting to report in an integrated manner. The first corporate integrated reports appeared in 2002, but the new trend remained in the margins. Since 2010, the IIRC (International Integrated Reporting Council) has led the work on building the first Integrated Reporting (IR) framework, published in December 2013. The accounting profession has played a crucial role in pushing the idea of integrated reporting forward. Now it is looking at how it can best participate in IR corporate practice. This report is aimed at accountants who would like to get involved more closely, or even drive, the IR efforts within their company. We begin with an overview of the origins of IR combined with calls for its development, emphasizing the role of the accounting profession in the development of this new corporate reporting framework. Then we discuss the benefits of IR, centered on the holistic thinking it can foster in companies, enabling them to reconsider sustainability challenges and leveraging a stakeholder-inclusive approach to corporate reporting. We then focus on the involvement of accountants within the implementation of IR. Finally, we elaborate on today’s challenges for IR, which include developing a materiality matrix, designing a project mode for the first IR publication process, designing integrated information systems, and navigating the legal environment surrounding IR. The report is based on participative observation within a leading multinational company—pilot of the IIRC—semi-structured interviews with international experts and other multinational companies on their IR journey, as well as documentary evidence collected from 2011 to 2015.