The Bookkeeper's First Health Check
Before a single financial statement is drawn up, most bookkeepers run one quick check to see whether the books hang together. That check is the trial balance. It is not glamorous and it is not something a business owner ever needs to produce by hand, but it is the moment when the figures either prove they are arithmetically consistent or admit that something has gone wrong. Get a clean trial balance and you can build the year-end accounts on solid ground. Get one that does not balance and you know to stop and find the error before it spreads into the profit figure and the tax return.
This guide explains what a trial balance actually is, why it exists, how it is laid out, and what it can and cannot tell you. We work through a full example so you can see one for yourself, and we cover what bookkeepers do when the two sides refuse to agree.
What Is a Trial Balance in Accounting?
A trial balance is a list of every account in the bookkeeping system together with its closing balance, set out in two columns: debits on the left and credits on the right. The two columns are then totalled. Because of the way the records are kept, the two totals should be exactly equal. If they are, the books are arithmetically consistent and ready to be turned into financial statements. If they are not, there is an error somewhere that needs tracing.
The reason the totals should match comes straight from double entry bookkeeping. In that system every transaction is recorded twice, once as a debit and once as a credit of equal value. Post a hundred transactions correctly and you have posted equal debits and credits a hundred times over. Add up all the debit balances and all the credit balances at the end, and the two have no choice but to be equal. The trial balance is simply that self-check made visible.
So a trial balance is best thought of as a checkpoint rather than a report. Nobody outside the business ever sees it. It sits between the day-to-day recording of transactions in our guide to what bookkeeping is and the formal statements such as the balance sheet and the profit and loss account that are built from it.
Why Bookkeepers Prepare One
A trial balance earns its place for three practical reasons.
First, it catches arithmetic errors early. If you have posted only one side of a transaction, or entered two different figures for the two sides, the columns will not match and you are warned before the mistake reaches the accounts.
Second, it gathers everything in one place. Instead of hunting through dozens of separate accounts, you have a single tidy list of every balance in the business at one date. That makes it far quicker to spot a figure that looks wrong, such as a cash balance that is negative when it should not be or an expense that looks ten times too large.
Third, it is the launch pad for the financial statements. Once the trial balance is agreed, the income and expense balances feed the profit and loss account and the asset, liability and equity balances feed the balance sheet. The statements are, in effect, the trial balance sorted into a more useful shape.
The Trial Balance Format
The layout is deliberately simple. Every account sits on its own row, with its balance entered in either the debit column or the credit column depending on the type of account. The natural sides follow the rules of double entry: assets and expenses normally carry debit balances, while liabilities, income and equity normally carry credit balances.
| Account type | Normal balance |
|---|---|
| Assets (cash, bank, equipment, stock, money owed to you) | Debit |
| Expenses (rent, wages, depreciation) | Debit |
| Liabilities (loans, trade payables, VAT owed) | Credit |
| Income (sales, fees, interest received) | Credit |
| Equity (owner's capital, retained earnings) | Credit |
You put each balance in its natural column, total both columns, and check that they agree. That is the whole format.
A Worked Trial Balance Example
Imagine a small limited company at its year end. After every transaction for the year has been posted, the closing balance of each account is listed below. Watch how the two columns come out equal.
| Account | Debit | Credit |
|---|---|---|
| Bank | £18,400 | |
| Trade receivables (money owed by customers) | £7,200 | |
| Stock | £4,500 | |
| Equipment | £12,000 | |
| Trade payables (money owed to suppliers) | £5,100 | |
| Bank loan | £10,000 | |
| Share capital | £1,000 | |
| Retained earnings (brought forward) | £6,000 | |
| Sales | £96,000 | |
| Cost of sales | £41,000 | |
| Wages | £28,000 | |
| Rent | £9,000 | |
| Other overheads | £4,000 | |
| Totals | £124,100 | £124,100 |
Both columns total £124,100, so the trial balance balances. From here the bookkeeper can build the statements. The sales, cost of sales, wages, rent and other overheads lines form the profit and loss account, which in this example shows a profit of £14,000. The bank, receivables, stock, equipment, payables, loan, share capital and retained earnings lines form the balance sheet. The trial balance has done its job: it has confirmed the arithmetic and handed over a clean set of balances to work from.
The Errors a Trial Balance Will Not Catch
Here is the part that often surprises people, and it matters. A trial balance that balances does not prove the books are correct. It only proves that total debits equal total credits. Several kinds of error leave both columns equal while the accounts are still wrong, which is why a balancing trial balance is reassuring but never the final word.
- Error of omission. A transaction is left out completely. Neither side was posted, so the columns still match, but the books are missing a sale or a cost.
- Error of commission. The right amount is posted to the wrong account of the same type, for example a cost charged to the wrong expense account. Both sides are present and equal.
- Error of principle. A transaction is posted to the wrong type of account, such as buying a £2,000 machine but recording it as a repair expense rather than a fixed asset. The profit and the balance sheet are both distorted, yet the columns balance.
- Error of original entry. The wrong figure is entered for both sides, say £540 written as £450 throughout. The two sides agree, on a wrong number.
- Reversal of entries. The debit and credit are swapped, with the account that should have been debited credited instead and vice versa. The totals are unaffected.
- Compensating errors. Two separate mistakes happen to cancel each other out across the columns, hiding both.
The lesson is that a trial balance is a strong check on arithmetic and a weak check on judgement. It tells you the sums add up. It cannot tell you that the right transaction went to the right place. That is exactly why a person who understands the numbers still matters, even in a world where software keeps the columns equal automatically.
When It Does Not Balance: The Suspense Account
So what happens when the two totals do not agree? The first move is to look for the error: recheck the postings, confirm each balance, and look for a difference that hints at the cause. A difference that divides exactly by nine, for instance, often points to two digits being swapped, known as a transposition error.
If the books need to move on before the difference is found, bookkeepers park it in a suspense account. This is a temporary holding account that takes the exact amount needed to make the trial balance balance, so work can continue. It is never meant to stay. The suspense account is investigated and cleared as soon as the underlying error is traced, with the figure moved to wherever it should have gone. A suspense balance still sitting in the books at year end is a clear sign that something was never resolved, and it is one of the first things a good accountant looks for.
Where the Trial Balance Sits Today
In practice almost no one writes out a trial balance by hand any more. Accounting software such as Xero produces one on demand, and because the software enforces double entry on every posting, the columns nearly always balance on the first try. So is the trial balance obsolete? Not at all. Its role has shifted from a manual chore to a review tool. Running the trial balance and reading down it, line by line, is one of the quickest ways to sanity check a set of books: a balance with the wrong sign, an account that should be empty but is not, a figure that looks out of scale. The arithmetic check is now automatic. The judgement check, reading the list and asking whether each balance makes sense, is the part that still pays off.
Our View
We think the trial balance is underrated precisely because software made it easy. When it took real effort to balance, the trial balance commanded respect and attention. Now that it balances on its own, it is tempting to glance at it and move on. That is a mistake. The most useful minute an accountant spends on a set of books is often the one reading the trial balance from top to bottom and asking, of each line, does this look right? The columns matching tells you the machine did its job. Whether the numbers tell the truth is a separate question, and it is the one worth your attention.
How IAK Can Help
A trial balance is only as honest as the bookkeeping behind it. Our bookkeeping service keeps every transaction posted correctly through the year, with regular bank reconciliations, so your trial balance reflects reality rather than just happening to balance. We set up and support Xero so the underlying double entry runs automatically, and our accounting team takes those clean balances through to year-end accounts, corporation tax and Self Assessment, clearing any suspense balances and checking that every figure is in the right place.
If your books do not balance, carry an unexplained suspense figure, or simply make you uneasy, contact us for a free consultation and we will get them straight.
Sources
- Running a limited company: company and accounting records, GOV.UK, on the accounting records UK companies must keep, from which a trial balance is drawn.
- FRS 102, the financial reporting standard for most UK small and medium companies, published by the Financial Reporting Council, under which the financial statements built from the trial balance are prepared.