The great unbundling: Sovereignty, Liquidity, and the Post-SEPA Payment Landscape

This paper analyzes the structural and macroeconomic implications of the European transition from Interchange-based card networks to Sovereign Instant Payment rails (SEPA Instant/Wero). We posit that the regulatory enforcement of zero-marginal-cost settlement (Regulation (EU) 2024/886) effectively "unbundles" the traditional retail banking value proposition, dismantling the cross-subsidization model that historically funded consumer liquidity and fraud protection. By eliminating the 30-day credit float inherent in the card model, the transition to real-time settlement risks engineering a contraction in household purchasing power and a deflationary liquidity shock. Furthermore, we identify a "Data-Settlement Asymmetry" in B2B supply chains, where the velocity of funds outpaces the velocity of reconciliation. The paper concludes that financial institutions must pivot from monetizing transaction volume to monetizing liquidity provision and trusted data intermediation to survive the commoditization of the settlement layer.