A large proportion of the income of banks and financial institutions consists of an excess of interest and other property income over payments rather than from direct charges for services. This income is recorded in the allocation of primary income accounts rather than as an item of gross output in the production account, operating surplus would be negative. To overcome this a service charge is imputed, equal to net interest and other property income. Conceptual problems of how to allocate the charge to the users of services provided by financial institutions, (such as whether to allocate on the basis of the number or value of loan transactions), are overcome by creating a nominal industry which pays the total charge. The nominal industry has no gross output and makes a negative contribution to GDP. Its negative operating surplus counteracts the increased operating surplus of all other industries, which are not recorded as paying any of the imputed bank service charges.