Testing performed by the auditor to reduce detection risk to an acceptable level is referred to as substantive testing.
Substantive testing encompasses several types of testing, including substantive tests of transactions, substantive analytical procedures, and tests of details of balances.
Substantive tests of transactions are used to determine whether all six transaction-related audit objectives have been satisfied for each class of transaction. The six transaction-related audit objectives are occurrence, completeness, accuracy, transaction is properly included, transaction is properly classified, and transaction is recorded on correct date. This type of test is a more common approach for income statement balances.
A test of details of balances attempts to support an account general ledger balance, either balance sheet or income statement, by testing the final account total. The emphasis of most tests of details of balances is on the balance sheet.