Errors that cause understating or overestimating of the total. If a Trial Balance gives an incorrect picture, it means that errors exist somewhere in the system. An error of commission will lead to understating or overestimating of the total. The entries recorded in the journal and its posting in the ledger should be examined for such errors . It must be noted here that there might be transactions that are not recorded or posted at all. In such a scenario, the Trial Balance will always agree.