Open Innovation (OI) models have been studied in many fields. However, the challenges and opportunities of a possible OI paradigm application in external auditing have been under‐re‐ searched. Recent corporate scandals are currently triggering changes and improvements in the reg‐ ulatory framework by targeting, in particular, the dominance of the so‐called “Big Four”. The main research question is whether a permissioned blockchain ecosystem could better enhance an OI par‐ adigm and prove more suitable than the Semi‐Open Innovation (SOI) paradigm that currently shapes the external audit field. Some challenges are considered in this article. Notably, blockchain requires suitable legal frameworks to ensure legally binding transactions. Moreover, multidiscipli‐ nary teams and high investments are required to develop efficient blockchain ecosystems and ex‐ ploit the power of data analytics. Systematic analysis is performed based on a relevant literature review, along with abductive reasoning and applied modelling methodologies. The analyses demonstrate that the current Semi‐Open Innovation external audit model is inefficient because it has led to market concentration, conflicting interests, and even fraud. Therefore, the regulators’ role in promoting fully Open Innovation models in the audit industry is essential to ensure transpar‐ ency, information sharing, fair competition, innovation, and collaboration among audit profession‐ als. Hence, this research aims at providing a different perspective by focusing on the necessary as‐ sumptions needed to ensure successful application of technologies in the audit field. The innovative introduction of a permissioned blockchain‐based audit system is also suggested to ensure the feasi‐ bility of the shift from Semi‐Open to Open Innovation.