Abstract: Fractional banking for account holders is provided. An example system enables a bank account holder to subdivide the bank or credit account into subaccounts based on the account holder's specifications and issue blank checks, debit cards, credit cards, and gift certificates for the customized subaccounts. An example system extends a user interface for creating subaccounts within a master bank account of the user, assigning respective account numbers to each subaccount, assigning respective access devices, checks, or payment cards to each subaccount, and allotting assets of the master bank account to each subaccount. The system may statically partition assets between accounts, or dynamically allocate cash or available credit among accounts. The account holder can issue debit or credit cards for the subaccounts, and subject the cards to filters and spending rules specified by the account holder, such as custom expiration date, custom credit ceiling, dates and hours usable, and the like.