In principle, a careful evaluation of costs and benefits should be a wise rule for everyone who has to take any important decision. In particular, it is very important when a payment system reform is at stake. Since many stakeholders are involved in a payment system reform, the final decisions are going to be the result of several cost-benefit analyses and of “negotiation” among economic agents, in particular system providers, system participants, and end users. In this paper we will only focus on cost-benefit analysis, providing both theoretical guidelines and numerical examples. We conclude that past evaluations of payment system reforms mainly focused on qualitative assessments, hence overlooking quantitative ones. So, we suggest that it would be worthy for international institutions to spend some efforts to build, manage and make available to all countries a database on payments systems, with both relevant data and methods to assess costs and benefits. | A methodological toolkit to reform payment systems: An example of applied cost-benefit analysis