How do you bring public accountability for millions of dollars to a region where the population is largely uninformed and lacks the savvy to monitor the actions of the authorities? From 2006 to 2011, the mining industry in Peru transferred over ,774 million in royalties to municipalities located in key mining regions, in compliance with a 2004 mining canon law, but local officials have not always put these funds to the best use. With the support of Canadian, U.S., U.K. and Norwegian (through CommDev) donor partners, International Finance Corporation (IFC) responded to this need with an innovative project: Improving Municipal Investment (Mejorando la Inversion Municipal in Spanish, or MIM). MIM Peru empowers the population gives them a voice to demand accountability from their authorities in the use of royalties. For this Latin America and Caribbean (LAC) initiative, communications are essential. And the project team learned that developing effective communication is not a sprint it's a marathon! This smart lesson shares lessons learned about communications during project implementation.