Errors of Commission are those errors that are committed due to wrong posting of transactions, wrong totalling, or wrong balancing of the accounts. They can also arise from wrong casting of the subsidiary books or wrong recording of the amount in the books of original entry. These errors are of a clerical nature, and most of them affect the agreement of the Trial Balance.

For example, if Raj Hans Traders paid ₹25,000 to Preetpal Traders and the transaction was recorded correctly in the cash book, but Preetpal's account was debited with only ₹2,500, it would constitute an error of commission. This specific instance creates a short debit in the ledger account. Another example is a mistake made during the wrong totalling or wrong casting of subsidiary books.

The rectification process essentially involves two steps: first, cancelling the effect of the wrong debit or credit by reversing it; and second, restoring the effect of the correct debit or credit. To do this, one must analyse whether the error resulted in a short debit/credit or an excess debit/credit in the involved accounts.

The measure to rectify these errors involves passing a journal entry (if affecting two or more accounts) or using an explanatory note (if affecting only one account). Specifically, rectification is done by debiting the account with a short debit or excess credit, and crediting the account with an excess debit or short credit.