This guide presents practical advice to providers on how to build a viable network of agents, which is a critical component of a branchless banking service. This guide is based on more than a year of research that yielded data on more than 16,000 agents in Brazil, India, and Kenya. In-depth interviews were conducted with 466 agents and more than two dozen agent network managers and providers. The guide focuses on the experience of five successful branchless banking services: Banco do Brasil and Banco Postal in Brazil, EKO and FINO in India, and M-PESA in Kenya. Examples are also drawn from other mobile network operators, banks, and specialized banking providers, including several partners in CGAP's Technology Program. An Excel-based financial model accompanies this guide and helps providers analyze their overall business model and calculate how much revenue it generates for the agent supply chain.