This paper has argued that governments should reason publicly about the choices they make in the budget and the deviations they make from approved budgets. This is necessary to promote transparency and public deliberation about the budget, and provide a measure of government accountability to citizens. International actors already include public reasons in one form or another in global assessments of PFM and many countries already provide explanations and justifications in their budget documents. What is needed is a set of criteria for evaluating the adequacy of such reasons. This paper offers a set of criteria for judging both retrospective and prospective reasons, and a couple of examples of how these criteria might be applied. By further utilizing these criteria, we can continue to refine them and build a global consensus around what public reasoning about budgets actually entails.