In this paper, I address the call for a “new approach to sustainability reporting” (Lubin and Esty, 2014) based on the present “sustainability gap” and propose the concept of “digitally unified reporting.” This is achieved by reviewing two major trends from distinct bodies of literature: “integrated reporting” from the sustainability field and unified data based “XBRL-integrated reports” as established in financial reporting making use of the digital standard XBRL (eXtensible Business Reporting Language). Based on a systematic literature review, eight trend statements are derived pointing at gaps and issues in the field of sustainability reporting and management. Following this review, I propose a new concept called “digitally unified reporting” that addresses these issues. The core contribution is an XBRL-based approach to sustainability reporting that combines digital data management of sustainability performance measurement with digitally standardized sustainability reporting. To advance theory, “digitally unified reporting” is defined and discussed and positioned as a “twin track approach” to sustainability reporting (Burritt and Schaltegger, 2010) that provides both an inside-out and an outside-in perspective on sustainability reporting and management. The major advancement and theoretical contribution of the proposed concept is a time-ontological shift due to 24/7/365 digital transparency. This proposed shift is from retrospective reporting on past performance to digitally enabled and interoperable real-time transparency of performance measurement and reporting for managers and external stakeholders. Finally, the concept is compared to current conventional reporting approaches.