Definition of a Trial Balance
A trial balance is a bookkeeping or accounting report that lists the balances in each of an organization's general ledger accounts. (Often the accounts with zero balances will not be listed.) The debit balance amounts are listed in a column with the heading "Debit balances" and the credit balance amounts are listed in another column with the heading "Credit balances." The total of each of these two columns should be identical.
Examples of the Trial Balance's Use
The trial balance is not a financial statement. It is mainly an internal report that is/was useful in a manual accounting system. If the trial balance did not "balance" it signaled an error somewhere between the journal and the trial balance. Often the cause of the difference was a miscalculation of an account balance, posting a debit amount as a credit (or vice versa), transposing digits within an amount when posting or preparing the trial balance, etc.
Today's accounting software has been written to eliminate those errors. Hence, the trial balance is less important for bookkeeping purposes since it is almost certain that the general ledger and the trial balance will have the debits equal to the credits.
The trial balance continues to be useful for auditors and accountants who wish to show 1) the general ledger account balances prior to their proposed adjustments, 2) their proposed adjustments, and 3) all of the account balances after the proposed adjustments. The adjusted amounts make up the adjusted trial balance, and the adjusted amounts will be used in the organization's financial statements.