Money is central to the functioning of economies, yet for the pre-modern period, our knowledge of monetary systems is still evolving. Until recently, historians of the medieval world have conflated the use of coins with a high degree of monetization. States without coinage were considered under-monetized. It is becoming more evident, however, that some medieval states used money in complex ways without using coinage. Moneys of account supplanted coins wholly or in part. But there is an imbalance of evidence: coins survive physically, while intangible forms of money leave little trace. This has skewed our understanding.