In accordance with the accounting rules, the different account categories are treated as follows:
| Financial assets accounts | |
| Debit | Credit |
| Opening balance | |
| Increase | Decrease |
| Closing balance | |
| Liability accounts and Capital accounts | ||
| Debit | Credit | |
| Opening balance | ||
| Decrease | Increase | |
| Closing balance | ||
| Expense accounts | |
| Debit | Credit |
| Expenses | Decrease in expenses |
| Transfer of expenses, Transfers of costs | |
| Income accounts (Revenue accounts) | |
| Debit | Credit |
| Decrease in income | Income |
| Transfer of expenses, Transfers of costs | |
When different categories of accounts are treated in accordance with the main accounting principles and rules, then it is clear and easy to understand how every transaction has to be accounted. Every case to be considered from the perspective of a single account, and the nature of event has to be determined at first. Thereafter, the relevant accounting rule applies and the same amount are posted on the debit side of one account and on the credit side of another account, i.e., transaction affects at least two accounts. Such a double entry accounting system brings a possibility of checking the accounts, because the total sum of the entries on the debit side always has to be equal to the total sum of the entries on the credit side. If as a result of such check a debit balance is not equal to the credit balance, it means that there are errors in the records or calculations.
Expenditure decrease and costs transfer is called an expense adjustment, as well as, income decrease and income transfer is called the revenue adjustment.