Collaboration and sharing of resources is critical for research. Authentication and Authorisation Infrastructures (AAIs) play a key role in enabling federated interoperable access to resources. The AARC Technical Revision to Enhance Effectiveness (AARC TREE) project takes the successful and globally recognised “Authentication and Authorisation for Research Collaboration” (AARC) model and its flagship outcome, the AARC Blueprint Architecture (BPA), as the basis to drive the next phase of integration for research infrastructures: expand federated access management to integrate user-centring technologies, expand access to federated data and services (authorisation), consolidating existing capacities and avoiding fragmentation and unnecessary duplication. The main objectives of the AARC TREE project are to: (i) Capture and analyse new Authentication and Authorisation interoperability requirements (as emerging that support integration use-cases across the thematic area) and provide a landscape analysis of AAIs services (including gaps) in the RIs represented in AARC TREE (ii) Define and validate new technical and policy guidelines for the AARC BPA that address RIs use-cases. This will improve the integration of RIs across thematic areas and increase the ability of RIs to support emerging needs (iii) Expand the number of research communities that can implement the AARC BPA and/or the AARC guidelines, by providing a validation environment and toolkits. At the same time support existing AARC communities in adopting new guidelines (iv) Bring RIs, e-Infrastructures and relevant stakeholders together to align strategies to integrate new technologies, better interoperate and share resources across thematic areas and produce a compendium and recommendations for different stakeholders