Cross acceptance is an aspect of the technical and legal process principally aimed at establishing the fastest route to the deployment of products, systems or processes (PSP) in a target (new) context or environment. The PSP considered for cross acceptance is generally assumed to satisfy the qualifications for reliability, tolerable safety and environmental performance in their native (original) context or environment. The target application is also assumed to possess significant synergies with the native environment, thus making the deployment technically feasible and commercially viable/advantageous without significant alterations. However, the essence of cross acceptance currently relates to the assurance of safety and potentially environmental performance of PSP which are subject to a regulatory regime. In the absence of systematic guidance and specific standards, a structured and risk based framework for cross acceptance of PSP is developed in this paper comprising seven core principles. This guidance draws upon a significant experience of the author on development and application of systemic frameworks for risk and safety assurance within the safety critical industries and more recently the railways. The principles are universal and particularly pertinent to safety critical systems where no systematic and efficient framework for their adoption and application in new applications or environments exists.