A trial balance that agrees proves only one thing: the debits and credits you posted have equal totals. It says nothing about whether each entry went to the right account. This page shows three errors that hide inside balanced totals, and how to find and correct them.
What is the student’s moment here?
“My trial balance balances, but my answer is marked wrong. What else is there to check?” Checking totals is the last step of the ledger, not the proof. You now need a second question: does each account hold the right kind of item?
The trial-balance and error detective lets you test an authored error scenario and shows whether it can be detected from the totals.
A worked example with three hidden errors
A small trader records these events in the ledger.
- Capital of RM10,000 paid into the cash box.
- A printer for the office bought for cash, RM1,200.
- The electricity bill paid in cash, RM300.
- Goods for resale bought for cash, RM2,000.
- Cash sales, RM3,000.
- Goods sold on credit to Ali, RM500.
What was actually posted. The printer was debited to Purchases. The electricity bill was debited to Rent. The credit sale to Ali was never posted.
| Account | Debit (RM) | Credit (RM) |
|---|---|---|
| Cash (10,000 − 1,200 − 300 − 2,000 + 3,000) | 9,500 | |
| Purchases (1,200 + 2,000) | 3,200 | |
| Rent | 300 | |
| Capital | 10,000 | |
| Sales | 3,000 | |
| Totals | 13,000 | 13,000 |
The totals agree. Yet three entries are wrong.
What it should have been.
| Account | Debit (RM) | Credit (RM) |
|---|---|---|
| Cash | 9,500 | |
| Receivables (Ali) | 500 | |
| Equipment | 1,200 | |
| Purchases | 2,000 | |
| Electricity | 300 | |
| Capital | 10,000 | |
| Sales | 3,500 | |
| Totals | 13,500 | 13,500 |
The three errors named
- Error of principle: the printer is an asset, not a purchase of goods for resale. Correct with Debit Equipment 1,200, Credit Purchases 1,200.
- Error of commission: electricity went to the wrong expense account, of the same type. Correct with Debit Electricity 300, Credit Rent 300.
- Error of omission: the credit sale is missing on both sides. Correct with Debit Receivables (Ali) 500, Credit Sales 500.
What the errors did to profit
Ignoring inventory at the end for simplicity, the wrong ledger gives profit of 3,000 − 3,200 − 300 = a loss of RM500. The corrected ledger gives 3,500 − 2,000 − 300 = a profit of RM1,200. The difference is RM1,700, which is the printer taken out of expenses (1,200) plus the missing sale (500).
Check: 1,200 + 500 = 1,700, and 1,200 − (−500) = 1,700. Both routes agree.
The mistake to avoid
A student who sees the totals agree writes “accounts are accurate” and stops. Another common slip is that, when a real difference appears, the student adds a figure to “make it agree” or forces it into suspense without looking for the cause.
The correction is to treat agreement as a minimum test. Then ask: did each item go to the right account, of the right type, on the right side? The correction lessons show how to use a suspense account only for a difference you cannot yet explain, and the lesson on avoiding agreement as proof builds this habit.
Self-check
1. Rent of RM600 was debited to Insurance. Does the trial balance agree? Name the error.
Show answer
Yes, it agrees, because the debit went to a wrong account but for the right amount, and the credit to Cash was correct. It is an error of commission. Correct with Debit Rent 600, Credit Insurance 600.
2. A cash sale of RM450 was debited to Cash but the credit to Sales was not made. What happens to the trial balance?
Show answer
Debits exceed credits by RM450, so the trial balance does not agree. This is a one-sided entry. The missing credit of RM450 to Sales is what a suspense account would hold until found.
3. Rent is debited RM100 too much and Wages are debited RM100 too little. Does the trial balance agree?
Show answer
Yes. The two errors cancel, so total debits are unchanged. These are compensating errors, and the trial balance cannot reveal them.
Where to go next
Work through errors a trial balance can reveal and errors that do not break equality, then try the trial balance and error limits practice set. The percentage-base explorer is useful once corrected profit figures lead to percentage questions, because the base you choose changes the answer.
When balanced totals still hide wrong entries in your homework, online one-to-one Accounting tuition can help you trace postings step by step.