If your trial balance does not balance, start with the difference between the two totals. Halve it and look for a balance of that amount entered on the wrong side. Divide it by 9 and, if it divides exactly, look for two digits swapped. Then re-add both columns, check each balance was copied across correctly, and check every journal entry was posted on both sides. Those five steps find almost every error.
An unbalanced trial balance is frustrating, but the difference is a clue, not just bad news. This guide explains what each test tells you, works through a real example, and covers the errors a trial balance can never catch, even when it balances perfectly.
What a trial balance checks
A trial balance lists every ledger account with its balance in either the debit or the credit column. Because every journal entry has equal debits and credits, the two column totals must agree if everything was recorded and posted correctly. When they do not, somewhere the rule was broken. The trial balance will not tell you where, but the size of the difference usually narrows it down.
Step 1: Study the difference
Subtract the smaller total from the larger one, then run these tests.
| Test | What it suggests | Example |
|---|---|---|
| Difference ÷ 2 matches a balance | That balance is in the wrong column, or an entry was posted to the same side twice | A $360 credit balance listed as a debit creates a $720 difference |
| Difference ÷ 9 is a whole number | A transposition (digits swapped) or a slid decimal point | Writing 540 for 450 gives a difference of 90; 90 ÷ 9 = 10 |
| Difference matches a transaction | One side of that entry was never posted | A $1,250 payment debited to rent but never credited to cash |
| Difference is a round number | An addition error in a column or a ledger account | A column total out by exactly $1,000 or $100 |
The divide-by-9 test works because swapping two digits always changes a number by a multiple of 9. So does moving a decimal point: 2,500 written as 250 is a difference of 2,250, which is 9 × 250.
Step 2: Re-add both columns
It sounds too obvious to bother with, but simple addition errors are more common than any other cause, especially in a long trial balance prepared by hand. Re-add each column, then re-add any ledger accounts with a lot of entries.
Step 3: Check each balance was copied correctly
Trace every balance from the ledger to the trial balance. Look for three things: a figure copied wrongly, a balance in the wrong column, and an account left out altogether. Normal balances help here. Assets, expenses and drawings normally have debit balances; liabilities, equity and revenue normally have credit balances. Any balance in the "wrong" column deserves a second look, although contra accounts such as accumulated depreciation are legitimate exceptions.
Step 4: Check for half-posted entries
Go back through the journal and confirm both sides of every entry reached the ledger. A one-sided posting, where an account is debited but the matching credit is forgotten, is one of the most common causes of an imbalance. Compound entries with three or more lines are where this happens most.
A worked example
A trainee's trial balance for Oakridge Tutoring shows debits of $48,620 and credits of $47,900. The difference is $720, with debits too high.
- Halve it: $360. Is there a credit balance of $360 sitting in the debit column? Yes: Discount Received of $360 has been listed as a debit. Moving it to the credit column takes $360 off the debits and adds $360 to the credits, closing the gap completely.
- Divide by 9: 720 ÷ 9 = 80, so a transposition was also possible. But the halving test found an exact match first, which is why it is worth running before anything else.
Corrected totals: debits $48,260 and credits $48,260. In practice, check the "halve it" candidates first, then the divide-by-9 candidates, then start re-adding and tracing.
If you cannot find it: the suspense account
When a difference cannot be found before the accounts must be prepared, the difference is temporarily placed in a suspense account so the trial balance agrees. Each error is corrected through the suspense account as it is found, until the balance is cleared to zero. A suspense account is a holding place, not a solution; it should never appear in the final financial statements.
Errors a trial balance cannot catch
A trial balance that balances is not proof the books are right. These errors keep the debits and credits equal:
| Error | What happened | Example |
|---|---|---|
| Omission | A transaction was never recorded | A supplier invoice left in a drawer |
| Commission | Right type of account, wrong account | A payment from customer A credited to customer B |
| Principle | Wrong category of account | A new computer debited to repairs expense |
| Original entry | The wrong amount on both sides | A $3,200 invoice recorded as $2,300 |
| Complete reversal | Debit and credit swapped | Cash credited and sales debited for a cash sale |
| Compensating errors | Two mistakes that cancel out | Sales overcast by $100 and wages overcast by $100 |
These are found by reviewing transactions, reconciling the bank and control accounts, and comparing results with the previous period, not by re-checking totals. The bank reconciliation guide shows one of the most effective checks.
A quick checklist
- Work out the difference and note which side is higher.
- Halve it and look for a balance of that amount in the wrong column.
- Divide it by 9 and look for transpositions.
- Re-add both columns and any busy ledger accounts.
- Trace every ledger balance to the trial balance.
- Check every journal entry was posted on both sides.
Practice it
The instinct for spotting errors comes from preparing trial balances yourself. Accountely's trial balance challenges score each account individually, so you see exactly which figure is wrong instead of only an unbalanced total. To go back a step, T-accounts explained covers posting and balancing ledger accounts. It's free to start.
Frequently Asked Questions
Why is my trial balance not balancing?
The most common causes are addition errors, a balance copied into the wrong column, a transposed figure, and an entry posted on only one side. Work out the difference between the totals, then halve it and divide it by 9 to narrow down the likely cause.
What does it mean if the trial balance difference is divisible by 9?
It usually means two digits were swapped (a transposition, such as 72 written as 27) or a decimal point slipped. Both errors always change a number by a multiple of 9.
Can a trial balance balance and still be wrong?
Yes. Errors of omission, commission, principle, original entry, complete reversal and compensating errors all leave debits equal to credits. A balanced trial balance only proves the arithmetic of double entry was kept.
What is a suspense account?
A temporary account used to hold a trial balance difference until the errors causing it are found. Each correction is posted through the suspense account until its balance is zero.