Understanding challenges for future Results-Based Payment (RBP) of the REDD+ are crucial to the REDD+ policymakers. So, there was a question of what will be the challenges and measures of going ahead to the RBP of REDD+. The primary objective of this study is to consider the REDD+ finances emphasizing private investment and finding the challenges and measures of future financing to the REDD+ program in developing countries. As a specific instance, it outlines and makes arguments on how developing countries, using Bangladesh as a case, can go ahead of REDD+ implementation with finances from private investors from developed countries. The study finds that most forest carbon investment has been taken place in the voluntary carbon market as part of corporate social responsibility (CSR) as well as philanthropic contribution. It also finds the demands of REDD+ credits uncertain in the market due to the lack of security of the funding. Japanese companies and researchers suggested a fair democratic system, stable and improving legal system, low corruption, improved national forest governance in the developing countries for their possible private investment for REDD+. The study will be useful for REDD+ practitioners and policymakers in developing countries and Bangladesh, in particular.