Algorithms and methods to couple and link multiple model types are often needed to tackle some of the most challenging problems in materials' simulations. Developing these represents both a complex and fascinating intellectual challenge, and a pressing need to tackle realistic systems in applied and industrial research. We summarize here the conclusions of the meeting, where we have identified the areas where coupling- and linking efforts would have the greatest impact, and which should be the policy recommendations to make to the Commission to facilitate this impact. This expert meeting, convened by the European Materials Modelling Council and hosted by CECAM, gathered some of the foremost experts across different domain areas, with the goal of identifying a roadmap for coupling and linking simulations that can act as a manifesto for the field, and inform future policy makers of the algorithmic and methodological developments needed and of their relevance and role in accelerating simulation-driven innovation.