This article studies the expiry and accreditation of Environmental Permits. It provides a review of the expiry of Environmental Permits, its normative consecration and its implementation by the Environmental Assessment Agency and the Superintendency of the Environment. Then, it raises ten legal-practical dilemmas around the expiry and accreditation of Environmental Permits. In particular, it examines questions of legality, legal certainty, means for contesting and administrative coordination. It highlights the lack of regulation under which projects remain once their implementation has been accredited; the absence of mechanisms that effectively force their continuity; and external situations that may affect their continuity. In this context, the work intends to approach the question of whether in the first ten years of application of the expiry of Environmental Permits, the aim that the legislator had in mind when including article 25 ter in Law No. 19300 is fulfilled: that projects are executed under similar baseline conditions to those considered in the environmental impact assessment procedure. This, it is argued, has not been sufficiently achieved. A series of regulatory adjustments are necessary, which are outlined throughout the study.