Finding and correcting accounting errors

What an accounting error is

An accounting error is an unintentional misstatement in the books: an amount recorded wrongly, in the wrong account, in the wrong period or not at all. It matters because some errors unbalance the trial balance and are easy to find, while others leave it perfectly balanced and survive into the financial statements unless someone reconciles, reviews and analyses the accounts.

The difference between error and fraud is intent, not mechanics. The techniques below find both, which is why auditors apply them too. The guide works from the classic error types through suspense accounts and correcting entries to the treatment of material prior-period errors under IAS 8, the point at which a bookkeeping problem becomes a restatement of published accounts.

Six errors a balanced trial balance will not reveal

A trial balance proves only that debits equal credits. Any error that affects both sides equally passes straight through it. These are the errors that matter most in a modern ledger, because an ERP that refuses unbalanced journals has removed most of the other kind. Our guides on debits and credits and on the general ledger explain the mechanics these errors break.

• Omission: a transaction is not recorded at all, such as a supplier invoice left in a drawer at year end
• Commission: the right type of account but the wrong one, such as a receipt from customer A credited to customer B
• Principle: the wrong class of account, such as a EUR 24,000 van posted to motor expenses instead of vehicles
• Original entry: the source figure is wrong and posted consistently, such as an invoice for 1,850 keyed as 1,580 on both sides
• Complete reversal: the correct accounts and amount with debit and credit swapped
• Compensating: two unrelated errors of equal size cancel out, such as sales overcast by 500 and wages overcast by 500

Errors that do unbalance the trial balance

One-sided postings, unequal debit and credit amounts, posting both sides to the same side, casting (addition) errors in a day book, and balances extracted to the wrong column all create a difference. In spreadsheets and manual ledgers these remain common; in an integrated system they mostly appear in imports, interfaces and opening balances.

Two quick arithmetic tests narrow the search. First, halve the difference: if one entry was posted to the wrong side, the trial balance is out by twice its amount, so look for an entry equal to half the difference. Second, divide by 9, as the next section explains. After that, compare each account with the prior month and the budget, because an error big enough to matter usually shows up as an unexplained movement.

Transpositions, slides and the divisible-by-9 check

A transposition swaps two digits; a slide moves the decimal point. Both produce a difference that is exactly divisible by 9, because any number and a rearrangement of its digits leave the same remainder when divided by 9, and a slide multiplies or divides by a power of 10, which also leaves the remainder unchanged. The quotient then tells you where to look.

For an adjacent transposition, the quotient divided by the relevant power of 10 equals the gap between the two swapped digits. A difference of 360 gives 40, so look for two adjacent digits in the tens and hundreds positions that differ by 4. For a one-place slide, the quotient is the smaller of the two numbers, so a difference of 2,250 points to 250 recorded instead of 2,500. A difference divisible by 9 is a strong hint, not proof: about one random difference in nine is divisible by 9 by chance.

• Transposition: 5,840 recorded as 5,480; difference 360; 360 divided by 9 = 40; the swapped digits 8 and 4 differ by 4
• Slide: 2,500 recorded as 250; difference 2,250; 2,250 divided by 9 = 250, the amount actually recorded
• Wrong side: a 450 discount credited instead of debited; the trial balance is out by 900, twice the entry

Using and clearing a suspense account: worked example

When a trial balance will not agree and the accounts must be produced, the difference is parked in a suspense account and cleared as each error is found. A suspense balance is never left in published accounts; it is a to-do list with a value.

A company's trial balance shows credits of EUR 312,900 and debits of EUR 312,360, so a debit of EUR 540 is posted to suspense. Two errors are then found. A EUR 450 discount allowed was credited to the discount allowed account instead of debited, understating debits by 450 and overstating credits by 450. A telephone bill of EUR 1,260 was posted to the expense account as 1,620, overstating debits by 360. Net effect: credits exceed debits by 900 minus 360, which is the EUR 540 in suspense.

The corrections clear suspense to nil (540 minus 900 plus 360 = 0) and reduce reported profit by EUR 540: expenses rise by 900 for the discount and fall by 360 for the telephone bill. A third error found at the same time, EUR 2,400 of repairs capitalised as equipment, is an error of principle and goes nowhere near suspense because it never unbalanced the trial balance.

• Error 1: Dr Discount allowed 900 / Cr Suspense 900
• Error 2: Dr Suspense 360 / Cr Telephone expense 360
• Error 3: Dr Repairs and maintenance 2,400 / Cr Equipment 2,400
• Suspense check: opening Dr 540, less 900, plus 360 = nil

Writing correcting entries that an auditor will accept

A good correcting entry is a new, dated, referenced journal, never an overwrite or deletion of the original. The reliable method has three steps: write down the entry that was made, write down the entry that should have been made, and post the difference. The narration should cite the original document number, the reason and the approver, so the correction can be traced both ways.

Take the van. It cost EUR 24,000, was bought on 1 October and was expensed. The company depreciates vehicles at 20% straight line with a monthly charge. At the 31 December year end the correction is Dr Vehicles 24,000 / Cr Motor expenses 24,000, and then the depreciation that should already exist: 24,000 x 20% x 3/12 = 1,200, posted as Dr Depreciation expense 1,200 / Cr Accumulated depreciation 1,200. Profit rises by 22,800 net.

Where the original entry is simply wrong in every respect, reversing it in full and posting the correct one is clearer than a net adjustment. It creates two extra lines, but each line means something on its own, which matters when the auditor tests journals individually.

Prior-period errors under IAS 8

IAS 8 defines prior-period errors as omissions and misstatements in prior-period statements that arise from failing to use, or misusing, reliable information that was available when those statements were authorised for issue and could reasonably have been obtained. Mistakes in arithmetic, misapplied policies, oversights, misinterpreted facts and fraud all qualify. New information that was not available then is not an error; it is a change in estimate, accounted for prospectively.

IAS 8 para 42 requires a material prior-period error to be corrected retrospectively in the first set of statements authorised after its discovery: restate the comparatives for the period in which it occurred, or, if it occurred before the earliest period presented, restate the opening balances of assets, liabilities and equity for that period. The correction does not go through current-year profit. Where period-specific effects are impracticable to determine, the standard allows restatement from the earliest practicable date.

A restatement also triggers a third statement of financial position at the start of the earliest comparative period when the effect on it is material, and the disclosures in IAS 8 para 49: the nature of the error, the amount of the correction for each line item and each prior period presented, and the correction at the start of the earliest period. From 2027, IFRS 18 renames IAS 8 as Basis of Preparation of Financial Statements; the error-correction requirements continue; our guide on IFRS 18 presentation and disclosure explains the wider changes.

Worked example: restating a cut-off error

During the 2026 year-end close, the finance team finds that goods shipped on 3 January 2026 were invoiced and recorded as 2025 revenue: sales of EUR 200,000 with a cost of EUR 150,000. The 2025 statements have been issued, and EUR 50,000 is material to them. Tax is ignored here for simplicity; in practice the tax effect is restated as well.

In the 2026 statements, the 2025 comparatives are restated: revenue down 200,000, cost of sales down 150,000, profit down 50,000; closing receivables down 200,000, closing inventory up 150,000, and retained earnings at 31 December 2025 down 50,000, which our guide on retained earnings shows flowing through the statement of changes in equity. The balance sheet still balances: assets fall by 50,000 and so does equity.

In the 2026 ledger, where 2025 is closed, one journal moves the sale into the correct year. The receivable was collected in January as normal, so no receivable adjustment is needed in 2026.

• Dr Retained earnings brought forward 50,000
• Dr Cost of sales (2026) 150,000
• Cr Revenue (2026) 200,000
• Check: debits 200,000 = credits 200,000; 2026 profit now includes the 50,000 margin that belongs to it

Preventing errors rather than finding them

Most errors are caught by routine controls long before an auditor sees them. The controls that catch the six invisible error types are reconciliations (bank, sub-ledger to control, supplier statements), cut-off checks at period end, review of manual journals, and analytical review of each account against last month, last year and budget. Our guides on bank reconciliation, balance sheet reconciliation and the month-end close checklist cover each in depth, and the guide on journal entry testing explains how auditors look for entries that are wrong on purpose.

Period locking is the other half. Once a month is reconciled and reported, it should be closed so that a late posting cannot silently change figures already reported. A correction then has to be made visibly in the open period, with a reference back to the period it relates to.

Finding and correcting errors in Skyline Nexus ERP

Skyline Nexus ERP removes the unbalancing class of errors at the source: a manual journal needs at least two lines and is rejected unless total debits equal total credits, and the Balance Sheet report shows Balance Sheet is not balanced with the difference if the ledger ever fails to balance. Accounts can be flagged Requires Cost Center, Requires Party or not Allow Manual Posting, which stops lines being posted without the analysis they need and keeps manual entries off accounts meant only for automatic postings.

Corrections follow the audit-friendly route described above. Only draft journals can be deleted; a posted journal is reversed with a Reversal Date and reason, creating a mirror-image entry, and Correct Journal Entry reverses the original and opens a new entry pre-filled with its lines. A journal generated by a sale, purchase, payment or payroll is corrected through its source document: edit the document, and the journal re-posts.

Closed history stays closed: posting into a soft-closed or locked fiscal period is refused, so a prior-period correction has to be posted in an open period. The Data Verification report compares the trial balance with GL and POS transactions to surface gaps, and the Audit Trail records every reversal and correction with the user and the old and new values.