Due diligence -- the process by which a funder assesses an organization before deciding to invest -- can cause anxiety for grantmakers and grantseekers alike. In part, this is because it's poorly understood. In this guide, we dispel five myths, distinguish between legal compliance and the rest of the due diligence process, and clarify legal requirements. The Guide to Due Diligence responds to Project Streamline's Principle 1: Take a fresh look at information requirements. Every organization needs to determine its own tolerance for institutional risk and be responsible for thoroughly understanding the legal rules for grantmaking. Beyond that, we recommend imposing additional due diligence requirements with care.