The study investigates historic and current examples of asymmetric charges and user tariffs in fixed-to-mobile interconnection regimes today. It addresses a wide range of related issues and questions: customer affordability; customer education and awareness; numbering plan and billing; whether detailed cost models would be required; and whether asymmetric termination charges, while eliminating current market distortions, would create other distortions. Alternative implementation strategies are also considered, with an eye to practicality for developing countries. It concludes that the concept is feasible, and the study further provides ideas for piloting the concept in a limited number of countries.