5.1 Errors affecting the trial balance

A trial balance is a list of all ledger account balances taken at a given date, with debit balances in one column and credit balances in the other. Because every transaction is recorded with equal debits and credits, the two columns should have the same total. An error that breaks this equality makes the trial balance disagree, and so it signals that something has gone wrong in the books. This topic explains the errors that cause such a disagreement, how to recognise them from the size of the difference, and how to search for them in an orderly way. How the errors are corrected, how a suspense account is used and which errors leave the trial balance unaffected are covered in other topics of this chapter.

Purpose and limits of the trial balance

The trial balance is an arithmetic check on the double entry system. If total debits equal total credits, the books are arithmetically consistent and the financial statements can be prepared with more confidence. If the totals differ, at least one error exists and the statements must not be finalised until it has been found or the difference has been properly recorded. Example: at the end of the month, the accountant of a pharmacy extracts balances and finds debits of Ksh 640,000 against credits of Ksh 634,000, so a search for errors totalling Ksh 6,000 must begin.

A trial balance that agrees does not prove the books are correct. Some errors leave the two columns equal, and these are dealt with under errors that do not affect the trial balance. This topic concerns only errors that make the columns unequal.

Key points to remember:

• Equal totals: Debits equal credits when every entry has been correctly made in pairs and correctly extracted.
• Unequal totals: The columns differ when an entry is incomplete, unbalanced, added wrongly or extracted wrongly.
• Direction of the difference: The larger column shows which side is overstated or which side is understated.
• Single or multiple errors: The difference is the net result of all such errors, so several errors may partly cancel each other.
• Timing: The sooner a difference is investigated, the fewer entries have to be checked.

Types of errors that make the trial balance disagree

Errors that affect the trial balance arise at three stages: when the transaction is recorded, when ledger accounts are totalled and balanced, and when balances are copied into the trial balance. Each type changes the totals of the two columns in a predictable way. The types are explained one by one below.

Single-sided entry (one side omitted)

This error occurs when only the debit or only the credit of a transaction is posted, and the other half is left out. The totals differ by the amount of the missing entry. Example: a teachers' SACCO received Ksh 12,000 from a member as a loan repayment. The cash book was debited with Ksh 12,000, but the member's loan account was never credited.

Debit total is higher by: Ksh 12,000
Result: debits exceed credits by Ksh 12,000.

Debit and credit entries of different amounts

Here both sides are posted, but with different amounts, often because digits are transposed (swapped) on one side or a figure is misread. The difference equals the gap between the two amounts. A difference caused by transposition is always divisible by 9. Example: a hotel paid an electricity bill of Ksh 4,500. The electricity account was debited with Ksh 4,500, but the bank account was credited with Ksh 5,400.

Difference = 5,400 - 4,500
Difference = Ksh 900
Result: credits exceed debits by Ksh 900, and 900 ÷ 9 = 100, which is a whole number.

Two debits or two credits for one transaction

Here the transaction is recorded with both entries on the same side. The totals then differ by twice the amount of the transaction, so the difference is always even and half of it is the amount of the faulty transaction. Example: a primary school paid Ksh 8,000 for stationery. The stationery account was correctly debited, but the bank account was also debited instead of credited.

Difference = 8,000 + 8,000
Difference = Ksh 16,000
Result: debits exceed credits by Ksh 16,000. Check: 16,000 ÷ 2 = Ksh 8,000, the amount of the transaction.

Addition errors in ledger accounts

When the debit or credit side of a ledger account is added wrongly, the balance is wrong and the trial balance is out by the amount of the miscalculation. Such errors are often round figures such as 10, 100 or 1,000 when a digit is carried wrongly. Example: the milk sales account of a dairy farm has credit entries of Ksh 18,400, Ksh 22,600 and Ksh 15,000, but the total was written as Ksh 55,000.

Correct total = 18,400 + 22,600 + 15,000
Correct total = Ksh 56,000
Understatement = 56,000 - 55,000 = Ksh 1,000
Result: the credit balance is understated, so debits exceed credits by Ksh 1,000.

Balancing errors in ledger accounts

An account may be added correctly but still balanced wrongly, for instance by subtracting incorrectly or by carrying down the wrong figure. The balance on the account then differs from the true balance. Example: the receivables account of a county water office has debits of Ksh 74,500 and credits of Ksh 28,300.

Correct balance = 74,500 - 28,300
Correct balance = Ksh 46,200
The balance was carried down as Ksh 42,600, so the debit balance is understated by 46,200 - 42,600 = Ksh 3,600.
Result: credits exceed debits by Ksh 3,600, which is divisible by 9.

Errors made when extracting balances to the trial balance

Even when all ledger accounts are correct, mistakes may occur when balances are listed. The common ones are shown below.

• Balance omitted: A ledger balance is left out of the trial balance, so the column it belongs to is understated by that balance. Example: a building contractor forgot to list its Ksh 20,000 insurance balance, so debits are Ksh 20,000 too low.
• Balance entered on the wrong side: A debit balance is shown in the credit column, or the reverse. The difference is twice the balance. Example: a pharmacy lists a discount received balance of Ksh 15,000 in the debit column, so debits exceed credits by Ksh 30,000.
• Balance entered twice: The same balance appears two times in one column, which overstates that column by the balance. Example: a Ksh 9,000 rent payable balance is listed twice in the debit column, so debits exceed credits by Ksh 9,000.
• Wrong figure copied: The balance is copied with digits transposed or misread, giving a difference divisible by 9 when digits are swapped.
• Opening balance entered wrongly: An opening balance brought forward is entered with a figure different from the closing balance of the previous period, so the account starts wrongly and the error carries into the trial balance.

Effect of each error on the trial balance

The table compares how the main errors change the totals, and what the difference tells the accountant.

Clues from the size of the difference

The amount of the difference often points to the type of error. These clues guide the search but do not prove the cause, since several errors may combine.

• Divisible by 2: The error may be an entry on the wrong side or two entries on the same side. Halve the difference and look for a transaction or balance of that amount.
• Divisible by 9: The error may be a transposition of digits, such as 4,500 written as 5,400.
• Equal to a single amount in the books: The error may be a missing entry or an omitted balance. Compare the difference with transactions and balances of the same amount.
• A round amount such as 100 or 1,000: The error may be an addition error in a ledger account or in the day books.
• Which column is larger: Debits larger point to missing credits, extra debits or understated credit balances. Credits larger point to the opposite.

Procedure for locating errors

When the trial balance does not agree, the search follows a sequence from the quickest checks to the most detailed.

1. Re-add both columns: Add the debit and credit columns of the trial balance again, because a simple addition mistake is the cheapest error to find.
2. Find the difference: Subtract the smaller total from the larger and note which column is larger.
3. Apply the clues: Halve the difference, test it for divisibility by 9, and compare it with known transaction amounts and balances.
4. Check the extraction: Compare each ledger balance with its entry in the trial balance, looking for omitted balances, wrong sides, double entries and copying mistakes.
5. Re-add and re-balance the ledger accounts: Recalculate the totals and balances of the accounts, starting with the busiest ones.
6. Trace postings from the books of original entry: Check that the totals of the day books and cash book have been posted to both the debit and credit sides, and that each individual posting has the right amount.
7. Check opening balances: Confirm that all balances brought forward agree with the closing balances of the previous period.
8. Record any remaining difference: If the error cannot be found in time, the difference is placed in a suspense account until it is traced, as explained in the topic on the suspense account.

Worked example

Example: a wholesaler extracts a trial balance and obtains the following totals.

Total debits = Ksh 312,400
Total credits = Ksh 309,400
Difference = 312,400 - 309,400 = Ksh 3,000
Result: debits exceed credits by Ksh 3,000.

The accountant first re-adds both columns and confirms the totals. The difference is not divisible by 9 (3 + 0 + 0 + 0 = 3), so transposition is unlikely. It is divisible by 2, but half of it, Ksh 1,500, matches no transaction. Searching the cash book shows that a receipt of Ksh 3,000 from a customer was debited to the bank account, but the credit entry in the customer's account was never made. The error is a single-sided entry. The credit side of the receivables account was understated by Ksh 3,000, which explains why debits exceed credits by exactly that amount.

Chapter Summary

This chapter explored the various types of accounting errors and their impact on the trial balance. It began by identifying errors that affect the trial balance, such as incorrect ledger postings and arithmetic mistakes, and contrasted these with errors that do not affect the trial balance, including compensating errors and errors of omission. The chapter then detailed methods for correcting these errors, emphasizing the importance of accurate adjustments to maintain financial integrity. It introduced the suspense account as a temporary holding place for discrepancies identified during trial balance evaluation, explaining how these accounts facilitate error resolution. The discussion extended to how errors influence the reported gross and net profit, highlighting the need for adjustments to reflect true financial performance. Finally, the chapter concluded with the preparation of the final statement of financial position, demonstrating how corrected accounts provide a reliable basis for this key financial report.