The article explores why a common currency plan in Germany failed in the mid-16th century. It shows how different interests clashed during negotiations, leading to the unanimous agreement on the currency bill in 1551. However, the plan ultimately collapsed due to princes wanting to ease their debts with a bimetallic currency and Charles V's attempt to weaken a rival by manipulating currency values. Charles' actions caused resistance, increased implementation costs, and ultimately led to the failure of the common currency.