A system of accounting in which both costing and financial transactions are recorded in the same set of books. In other words, under such a system, only one set of account books is maintained to record both the cost and financial transactions in order to ensure that all relevant expenses are absorbed into their respective cost accounts.

An integral system of accounting (integrated system of accounting) requires no cost ledger because all control accounts are maintained in the financial ledger. A control account for each subsidiary ledger is maintained in the general ledger (GL).

This system does not require a cost ledger control account because both sides (debits and credits) of all transactions are recorded in respective accounts (see: features of integral system of accounting).