A virtual ledger is a set of account records kept in software on top of a pooled bank account. The bank account holds the actual money as a single balance. The virtual ledger records how much of that balance belongs to each customer, seller or purpose. Each entry in it is commonly called a sub-account or virtual account.
Payment platforms, marketplaces and banking-as-a-service programs depend on this arrangement. Funds are received into an FBO account or safeguarding account, and the ledger attributes them to the right party so that balances can be shown and payouts made. The ledger may be run by the bank, by a middleware provider or by the platform, and is usually reached through a ledger API. Sound design follows double-entry ledger principles. The total of all virtual balances must equal the money at the bank, and daily reconciliation is needed to prove it.