Errors of Principle : When a transaction has not been recorded as per the rules of debit and credit, or some other accounting principle has been ignored, the errors so arising are called 'Errors of Principle'. Example of such errors are:

i.A credit purchase of a fixed asset recorded in the Purchases Journal instead of the Journal Proper: This results in debiting the Purchases Account instead of the concerned fixed asset account. It means that a capital expenditure has been treated as a revenue expenditure. This is an error of principle. This does not disturb the debit-credit correspondence. Hence, the Trial Balance will not be affected.

ii.An expenditure Incurred on repairs of machinery debited to Machinery Account: As per rules it should have been debited to Machinery Repairs Account, as it is a revenue expenditure. Debiting to Machinery Account amounts to treating it as a capital expenditure. It is therefore an error of principle. This also does not affect the Trial Balance because the debit has been duly recorded, though in the wrong account.

iii.Salary paid to Shyam recorded in the Cash Book as a payment to Shyam. This results in debiting Shyam's personal account instead of the Salaries Account. This is also an error of principle and does not affect the Trial Balance.