A trial balance is a two-column list of every general ledger account and its ending balance — debits in the left column, credits in the right — prepared to check that total debits equal total credits. Because double-entry bookkeeping posts equal debits and credits for every transaction, the two column totals must match if everything was posted correctly. Accountants run this check at the end of each period, before building the financial statements, so posting errors get caught while they are still cheap to fix.
The document exists because ledgers are long and people miscopy numbers. A figure written on the wrong side, a $6,835 copied as $6,385, or one half of a journal entry that never made it into the ledger will each break the equality — and the trial balance is the tripwire that tells you something is off. It is a working paper, not a financial statement: nobody outside the company sees it, and its only job is to prove the arithmetic before the balance sheet and income statement inherit the numbers.
Three steps, in order.
1. Balance each ledger account. Total the debit side and the credit side of each T-account, then take the difference. The balance sits on whichever side is larger — for an account posted correctly, that is its normal side: debit for assets and expenses, credit for liabilities, equity, and revenues.
2. List every account that has a balance. Write the accounts in ledger order — assets first, then liabilities, equity, revenues, and expenses — and place each balance in its normal column. Accounts with a zero balance are skipped. You are listing ending balances, not the account's total activity.
3. Foot the columns and compare. Add each column (accountants call this footing) and write both totals at the bottom. If total debits equal total credits, the trial balance is done and the numbers can move on to adjustments and statements. If not, stop and find the error before doing anything else.
Here is the finished worksheet for a small tutoring company at the end of June.
| Account | Debit | Credit |
|---|---|---|
| Cash | $14,260 | |
| Accounts Receivable | $6,835 | |
| Supplies | $1,190 | |
| Equipment | $22,400 | |
| Accounts Payable | $4,910 | |
| Notes Payable | $12,000 | |
| Common Stock | $25,000 | |
| Service Revenue | $17,905 | |
| Salaries Expense | $9,730 | |
| Rent Expense | $5,400 | |
| Totals | $59,815 | $59,815 |
The columns match, so the postings are arithmetically consistent and these balances can flow into the adjusting process and the statements. Keep the order in mind for exams: assets, liabilities, equity, revenues, expenses — and a single ruled Totals line at the bottom.
Do not start rechecking everything from scratch. Compute the exact difference between the two totals first — the size and shape of that number usually points at the error.
Divide the difference by 2. If it divides evenly, look for that quotient posted on the wrong side. A balance on the wrong side throws the totals off by twice the amount: if Supplies ($1,190) landed in the credit column above, debits would foot to $58,625 and credits to $61,005 — a difference of $2,380, and $2,380 ÷ 2 = $1,190. Scan both columns for $1,190 and check its side.
Divide the difference by 9. If it divides evenly, suspect a transposition — two digits swapped in copying. Write Accounts Receivable's $6,835 as $6,385 and the debit column comes up $450 short; $450 ÷ 9 = $50, a whole number, which is the signature of a transposition. A slide (a decimal shifted, like $5,400 copied as $540) is also divisible by 9 — that one leaves a difference of $4,860.
Scan for the exact difference. If the difference matches one account's balance to the dollar, that account was probably skipped when the list was copied — or one side of a journal entry was never posted to the ledger. Search the ledger and the trial balance for the exact amount.
If none of the three tests hits, work backward mechanically: re-foot both columns, re-check each ledger account's balance, then trace each posting back to the journal until the difference surfaces. The error is always findable, because the difference is not random — some specific posting created it.
The trial balance tests one thing: that total debits equal total credits. Any error that keeps debits and credits equal sails straight through it.
So a trial balance that balances means the arithmetic is internally consistent, not that the books are right. Catching the errors above takes source-document review, reconciliations, and a reader who knows what the balances should look like.
Textbooks use one name for three snapshots taken at different points in the closing sequence. The unadjusted trial balance comes straight from the ledger at period end, before any adjustments. The adjusted trial balance is prepared after adjusting entries record accruals, deferrals, and depreciation — this is the version the financial statements are built from. The post-closing trial balance is run after closing entries zero out the revenue, expense, and dividend accounts; only permanent balance-sheet accounts remain on it, and it proves the ledger is clean for the next period.
Treating "it balances" as "it is correct." Column equality is a necessary condition, not a sufficient one. Exam questions exploit this constantly: a problem describes an entry posted to the wrong account and asks whether the trial balance still balances. It does.
Listing activity instead of balances. Each line is the account's ending balance — one number, on its normal side. Students sometimes copy a T-account's debit total and credit total as two separate figures, which double-counts the account and wrecks both columns.
Confusing it with the balance sheet. The trial balance is an internal checklist of every account, including revenues and expenses, with no classification. The balance sheet is a formal statement built later, showing only assets, liabilities, and equity, after net income has been folded into retained earnings.
A trial balance proves one equality: total debits = total credits. When the columns disagree, divide the difference by 2 (wrong-side posting), divide it by 9 (transposition), and scan for the exact amount (omitted posting) before rechecking anything line by line.
They are the same worksheet run at three points in the closing sequence. The unadjusted version comes straight from the ledger at period end; the adjusted version is prepared after adjusting entries and is the basis for the financial statements; the post-closing version is run after closing entries and contains only permanent balance-sheet accounts, because revenues, expenses, and dividends have been reset to zero.
No. It is an internal working paper used to check the ledger's arithmetic before the statements are prepared. External readers see the balance sheet, income statement, and statement of cash flows — never the trial balance.
A trial balance lists every ledger account, including revenues and expenses, in raw debit and credit columns to test that the totals match. A balance sheet is a formal statement of only assets, liabilities, and equity, prepared afterward, with revenues and expenses already collapsed into retained earnings.
No. It means total debits equal total credits. Omitted transactions, postings to the wrong account, duplicated entries, and amounts that are wrong on both sides all leave the columns equal while the balances are still wrong.
Swapping two adjacent digits changes a number by a multiple of 9 — writing 83 as 38 changes it by 45, and 45 ÷ 9 = 5. So when the two columns differ by an amount evenly divisible by 9, a transposed or slid figure is the most likely cause.
At minimum at the end of each accounting period, before the statements. In practice, accounting software recomputes it continuously, so most bookkeepers pull one monthly and any time they need to verify the ledger.