In this article, I trace how payment and money transfer systems in Cuba have expanded from underground courier services to digital platforms such as Airbnb and Bitcoin wallets. I focus here on payments being halted and deferred because of U.S. embargo restrictions that prevent correspondent relationships with Cuban retail banks and constantly flag transactions initiated in Cuba. Cubans and visitors to Cuba operating on these digital platforms are therefore exposed to new risks and forms of precarity. In the absence of a robust payment infrastructure, electronic transactions between the two countries have to be propped up and secured by networks of cash circulation. A social infrastructure of trust and informal networks emerges through which digital payment rails get repurposed to settle accounts, particularly when electronic payments get detained. This complicates the premise that cashless futures make payments more inclusive, efficient, secure, or in some cases decentralized, by showing how the histories of U.S. sanctions impede and cripple the ways electronic payment infrastructures work in practice, creating forms of exclusion for those located in "prohibited" regions of the globe.