In the evolving architecture of modern finance, the rise of central bank digital currencies (CBDCs) calls for a critical reassessment of how central banks account for money. More than a technical upgrade, CBDCs raise foundational questions about the nature of money, the structure of monetary systems and the institutional distribution of seigniorage. In our recent research, we have argued that money is a financial instrument that yields rents to its issuer. However, the prevailing accounting