What Is a Trial Balance? Definition, Example & How to Fix One That Doesn’t Balance

At month-end, the office manager at Beacon Family Dental pulls together every account balance to close out March. Debits: $147,750. Credits: $147,840. Off by $90. Nothing about the day-to-day work seemed wrong — patients were billed, supplies were ordered, payroll went out on time — but somewhere in thousands of individual entries, something doesn’t add up. That $90 gap is exactly what a trial balance is designed to surface, and finding it is a smaller, more mechanical puzzle than it might first appear.

This guide covers what a trial balance actually is, why it has to balance in the first place, the different types you’ll encounter, and — using Beacon Family Dental’s real $90 discrepancy as a worked example — exactly how to track down an error like this one and fix it.

What Is a Trial Balance?

A trial balance is a report listing every account from the general ledger, alongside its current debit or credit balance, totaled at the bottom to confirm that total debits equal total credits. It’s not a financial statement itself — it’s an internal working document, a checkpoint used before financial statements get built, to catch certain kinds of bookkeeping errors while there’s still time to fix them.

Every account that has a balance shows up on the trial balance exactly once, listed under whichever column — debit or credit — matches its normal balance: assets and expenses under debit, liabilities, equity, and revenue under credit. If the general ledger is the detailed transaction history for every account, the trial balance is the condensed, one-line-per-account summary of where each of those accounts currently stands.

Why Does a Trial Balance Need to Balance?

The answer goes back to double-entry bookkeeping: every transaction, without exception, affects at least two accounts and hits total debits and total credits by the same dollar amount. Do that correctly across thousands of transactions, and the sum of every debit balance in the general ledger should equal the sum of every credit balance, no matter how many accounts are involved.

Corporate Finance Institute’s overview of the trial balance and QuickBooks’ own explainer both cover this same core purpose if you want additional framing beyond what’s here. The trial balance is simply that arithmetic check, pulled out into its own report. If the two columns match, it doesn’t prove the books are perfect — as covered further down, some real errors don’t throw off this balance at all — but it does confirm that every transaction was recorded following the fundamental debit-equals-credit rule. If the two columns don’t match, something concrete and findable went wrong, and the trial balance is what flags it before it quietly flows into a balance sheet or income statement.

This is also why the trial balance is worth pulling before financial statements are built rather than after. Catching a $90 discrepancy at the trial balance stage means fixing one transposed number. Catching that same error after it’s already flowed into a finished income statement and balance sheet means correcting two additional reports, and possibly explaining a revised number to anyone who already saw the first version — a lender, a business partner, or the owner themselves.

Types of Trial Balances

A business typically prepares more than one version of the trial balance during a closing cycle, each serving a slightly different purpose:

• Unadjusted trial balance — pulled directly from the general ledger before any period-end adjusting entries (like accrued expenses or depreciation) have been made. This is usually the first draft, and often where the first-pass “does this balance?” check happens.
• Adjusted trial balance — the same report, after adjusting entries have been posted for accrued and deferred items. This version is what financial statements actually get built from.
• Post-closing trial balance — prepared after temporary accounts (revenue, expenses, and dividends/draws) have been closed out to retained earnings or owner’s equity at year-end, leaving only permanent balance sheet accounts. This confirms the books are ready to start the next period at zero for all temporary accounts.

Each version follows the exact same debit-equals-credit logic — the only thing that changes between them is which entries have been posted to the general ledger by the time the trial balance is pulled.

A Full Worked Example: Beacon Family Dental’s Trial Balance

Here’s the unadjusted trial balance the office manager at Beacon Family Dental pulled together for March, exactly as it came out of the books:

Debits and credits don’t match — the credit column is $90 higher. Before assuming a transaction is genuinely missing or duplicated, there are two quick mathematical checks worth trying first:

Check 1: Is the discrepancy evenly divisible by 9? $90 ÷ 9 = 10 — yes. A discrepancy divisible by 9 is the classic signature of a transposition error, where two digits in a number were accidentally swapped when it was copied from one place to another (for example, writing $46,450 as $46,540). This single check narrows the search dramatically before anyone has to re-examine every account.

Check 2: Is the discrepancy evenly divisible by 2? $90 ÷ 2 = $45. If an account with a $45 balance existed, that would suggest an amount was accidentally entered in the wrong column entirely — a debit recorded as a credit, or vice versa, which throws off the total by exactly double the actual amount. In this case, no $45 account exists, which rules this particular error type out and points the search back toward the transposition check instead.

Following the first lead, the office manager rechecks Service Revenue against the general ledger and finds it: the true ending balance was $46,450, but $46,540 was copied onto the trial balance worksheet — the “4” and “5” got swapped. AccountingTools’ own trial balance example walks through a similar correction process if you want to see a second worked case beyond this one. Correcting the transposition:

Balanced. The other thirteen accounts were never the problem — the entire $90 gap traced back to one transposed number in one account, which is exactly why the divisible-by-9 check is worth trying first: it turns a search through every account into a search through one likely candidate.

Common Reasons a Trial Balance Doesn’t Balance

Beacon Family Dental’s transposition is one of several common causes. In rough order of how often each shows up in practice:

• Transposition errors — digits swapped when copying a number, as in the example above (writing $46,450 as $46,540). Always divisible by 9, which is why that check comes first.
• One-sided entries — a transaction where only the debit or only the credit was posted, not both, often from an interrupted or incomplete manual entry. If Beacon’s bookkeeper had recorded a $500 supply purchase as a debit to Dental Supplies but never posted the matching credit to Accounts Payable, debits would exceed credits by exactly $500.
• Posting to the wrong column — a legitimate amount recorded as a debit when it should have been a credit, or vice versa. Always creates a discrepancy divisible by 2, since the error effectively counts the amount twice on the same side instead of once on each side.
• Arithmetic errors when totaling column sums — a simple addition mistake when summing either the debit or credit column itself, rather than an error in any individual entry. Re-adding both columns by hand (or letting software do it) is always worth trying before assuming a posting error exists at all.
• Omitted postings — an entire transaction that was recorded in the journal but never actually posted to its general ledger accounts, usually from an interrupted workflow between recording and posting.
• Duplicate postings — the same transaction accidentally posted twice, which (unlike most errors above) can still leave debits equal to credits if both sides were duplicated together, making it one of the trickier errors for a trial balance alone to catch — it usually surfaces instead through an inflated account balance during a routine reconciliation.

When the Error Can’t Be Found Right Away: Suspense Accounts

Sometimes a discrepancy resists both quick checks and a careful line-by-line review — the error is real, but not immediately locatable. Rather than delay closing the books indefinitely, many businesses post the unexplained difference to a temporary suspense account, which holds the discrepancy in plain sight while the investigation continues, without blocking the rest of the close process.

A suspense account is meant to be short-lived. Once the underlying error is found — sometimes days or weeks later, often when a related discrepancy shows up somewhere else and points back to the same root cause — the correcting entry clears the suspense account back to zero and moves the amount to wherever it actually belonged. A suspense account with a balance that’s been sitting untouched for months is generally a sign the underlying error was never actually resolved, just parked.

What a Trial Balance Cannot Catch

This is the detail that surprises people learning trial balances for the first time: a trial balance can be perfectly balanced and the books can still be wrong. Because the check only confirms that total debits equal total credits, it’s blind to errors that don’t disturb that balance:

• Errors of omission — a transaction that was never recorded at all, on either side. Nothing is out of balance because nothing was entered in the first place.
• Errors of commission — an entry posted to the wrong account, but on the correct side and for the correct amount. Paying a utility bill but debiting Rent Expense instead of Utilities Expense still keeps debits equal to credits — the trial balance has no way to know the wrong account was used.
• Errors of principle — a transaction recorded in violation of a proper accounting concept, such as recording a piece of equipment as an expense instead of an asset. Again, debits still equal credits; only the classification is wrong.
• Compensating errors — two unrelated mistakes that happen to cancel each other out, such as one account being understated by $200 at the same time a completely unrelated account is overstated by $200. The trial balance balances perfectly, hiding two real errors instead of one.

Catching these requires other controls — careful account coding at the point of entry, regular reconciliations, and periodic review by someone other than the person who made the original entry. This is exactly why auditing exists as its own discipline: an audit tests for exactly the kinds of errors a trial balance structurally cannot see.

How to Prepare a Trial Balance

1. Pull the ending balance for every account in the general ledger, following the order laid out in the chart of accounts — typically assets first, then liabilities, equity, revenue, and expenses. Any account with a zero balance for the period is typically still worth double-checking rather than skipping outright, since a zero balance can sometimes mean a transaction was never posted at all rather than genuinely reflecting no activity.
2. List each account once, placing its balance in the debit or credit column based on its normal balance type. An account should never appear split across both columns on a properly prepared trial balance — only its single net ending balance.
3. Total both columns independently, ideally by two different methods or people if the volume of accounts makes a manual arithmetic slip plausible.
4. Compare the two totals. If they match, move on to preparing adjusting entries (for an unadjusted trial balance) or financial statements (for an adjusted one). If they don’t, work through the discrepancy checks above before reviewing individual accounts line by line.
5. Document any correcting entries made along the way, so there’s a clear record of what was fixed and why — useful for anyone reviewing the books later, including an accountant at tax time or an outside auditor.

Trial Balance vs. Balance Sheet

These get confused constantly because they can look superficially similar — both list account balances — but they serve very different purposes:

A trial balance is a working document nobody outside the accounting function typically ever sees. A balance sheet is the polished, formatted report built using the trial balance’s numbers as its source — but only after the trial balance has actually confirmed those numbers are ready to use.

From Trial Balance to Financial Statements

Once an adjusted trial balance balances, its numbers flow directly into the financial statements: revenue and expense accounts populate the income statement (see also our guide to the single-step income statement format), while asset, liability, and equity accounts populate the balance sheet. Our broader guide to what financial statements are covers how these reports connect to each other once the trial balance clears this checkpoint. Under accrual accounting, this typically happens once per month at minimum, tightly connected to the business’s fiscal year close at year-end, when a post-closing trial balance also gets prepared to confirm the books are ready for the next period.

Common Trial Balance Mistakes

• Assuming a balanced trial balance means the books are error-free. As covered above, several real error types don’t disturb the debit-credit balance at all.
• Not checking for the divisible-by-9 and divisible-by-2 patterns first, and instead re-checking every account from scratch — a far slower path to the same answer in most cases.
• Fixing the symptom instead of the source. Adjusting a total to force the columns to match, rather than finding and correcting the actual underlying entry, hides the error rather than fixing it — and usually resurfaces as a bigger problem later.
• Skipping the unadjusted trial balance and going straight to adjusting entries. Confirming the books balance before adjustments makes it far easier to tell whether a later discrepancy came from the original entries or from an adjusting entry itself.
• Not keeping a record of correcting entries. Silently fixing a transposed number without documentation makes it harder for anyone reviewing the books later to understand what changed and why.

Frequently Asked Questions

What is a trial balance in simple terms? A trial balance is a report listing every account from the general ledger and its current balance, totaled to confirm that total debits equal total credits before financial statements are prepared.

What does it mean when a trial balance doesn’t balance? It means at least one bookkeeping error exists somewhere in the entries that fed the general ledger — commonly a transposed number, a one-sided entry, or an amount posted to the wrong column. It’s a signal to investigate, not itself the final report.

Why is a discrepancy divisible by 9 significant? A discrepancy that divides evenly by 9 is the mathematical signature of a transposition error — two digits accidentally swapped when a number was copied from one place to another. It’s one of the fastest first checks when a trial balance doesn’t balance.

Can a trial balance balance perfectly and still be wrong? Yes. Errors of omission, errors of commission (posted to the wrong account), errors of principle, and compensating errors can all exist in the books without ever disturbing the total debit and credit balance.

What’s the difference between an adjusted and unadjusted trial balance? An unadjusted trial balance is pulled before period-end adjusting entries, like depreciation or accrued expenses. An adjusted trial balance is pulled after those entries are posted, and is the version financial statements are actually built from.

Is a trial balance the same as a balance sheet? No. A trial balance is an internal working document listing every account, including revenue and expenses. A balance sheet is a formatted, external-facing report showing only assets, liabilities, and equity as of a specific date.

How often should a trial balance be prepared? Most businesses prepare one at least monthly, as part of closing the books for the period, with an additional post-closing trial balance prepared at year-end after temporary accounts are closed out.

What’s a post-closing trial balance? It’s the trial balance prepared after a business closes its temporary accounts — revenue, expenses, and owner’s draws — into retained earnings or owner’s equity at year-end, leaving only permanent balance sheet accounts with balances going into the new period.

What is a suspense account? A suspense account is a temporary holding account used when a trial balance discrepancy can’t be immediately located, letting the books close on schedule while the investigation continues. It should be cleared to zero once the actual error is found and corrected.

Does accounting software eliminate the need for a trial balance? Not exactly — most accounting software still generates a trial balance internally and generally won’t let a transaction post at all unless its debits equal its credits, which prevents many of the classic manual errors above. It’s still worth reviewing periodically, since software can prevent unbalanced entries without preventing entries posted to the wrong account entirely.

Final Thoughts

A trial balance doesn’t fix anything by itself — it just points at a number and says “this doesn’t add up yet.” That’s precisely its value. Beacon Family Dental’s $90 gap could have been buried in fourteen accounts and thousands of individual transactions, but the divisible-by-9 check narrowed it down to one likely candidate in minutes rather than hours.

What a trial balance can’t do is just as important to remember as what it can: a balanced trial balance is a necessary checkpoint on the way to accurate financial statements, not a guarantee that the books are perfect. Treat it as one layer of a larger system — built on a solid chart of accounts and an accurately maintained general ledger — rather than the final word on whether the books are right.