This tool provides concise and practical guidance on structuring contracts and contracting procedures for private military and/or security services, drawing on international norms and standards. It highlights the key role of effective contracting processes which integrate respect for IHRL and IHL, based on lessons and good practices from existing contracting procedures. The tool is primarily aimed at states, IOs, humanitarian organisations, and NGOs in their processes of contracting PMSCs, but will also be instructive for private clients.