The 2014 referendum on independence in Scotland provides an opportunity to examine the way that attitudes to and preferences for different monetary and currency options constrain constitutional preferences. An independent Scotland would have faced a range of potential monetary and currency options, including retention of the status quo, establishing a separate currency or joining the euro. Using data from a two-wave nationally representative survey we designed and conducted three months before and three months after the 2014 Scottish independence referendum we examine three different types of evidence to explore how beliefs and preferences over currency impacted referendum preferences: belief and knowledge questions about likelihood of retention of status quo; retrospective questions on key factors influencing vote; and survey experiments offering different currency scenarios. Across all three types of evidence, we find that currency and monetary factors had a high degree of influence on voting intention and vote choice. The data highlight the ways in which economic calculations structure constitutional preferences and in so doing show how state formation can be influenced by voter understandings of risk and uncertainty, specifically about currency.