Recognise errors a trial balance cannot expose
Classify the six syllabus errors that can leave trial-balance totals equal and distinguish them from one-sided errors.
Cambridge IGCSE Accounting 0452 / (9–1) 0985, 2027–2029 Version 1. These lessons follow the 2027–2029 syllabus only; the separate 2026 syllabus update is not yet mapped. Written practice is self-checked, not an official Cambridge grade. Full timed-paper practice and human subject-teacher review remain pending.
Before you begin
- No previous accounting study is assumed. Keep the business, transaction and accounting period in view, and distinguish a resource, a claim and a performance result.
Work on paper. Try each question before revealing help, and explain why your method works.
Quick readiness check
Which error is most likely to leave equal totals when both entries use the wrong amount?
What you will learn
- Recognise errors of commission, principle and original entry
- Explain omission, complete reversal and compensating errors
- Use trial-balance agreement without overstating its assurance
Six errors can preserve equal totals
An error of commission posts to the wrong personal account of the correct class. An error of principle uses the wrong class of account, such as charging equipment to repairs. An error of original entry records the wrong amount in the source and posts that same wrong amount to both accounts.
A complete omission leaves both sides unrecorded. A complete reversal records the correct accounts but reverses debit and credit. A compensating error occurs when two or more errors offset in their effect on the trial-balance totals.
Find evidence beyond the totals
These errors can leave debit and credit totals equal, so compare source documents with the journal, ledger account type, amount and posting direction. The trial balance is useful for arithmetic; it is not a substitute for checking transaction evidence.
A one-sided entry or a posting to the wrong side of one account may make the totals differ. Do not classify every unexplained difference as a suspense-account error until the underlying entries are checked.
Pause and explain
A sale of $470 is completely omitted from the records. Which error is this?
Worked example
A $900 equipment purchase is recorded as a debit to Repairs and a credit to Bank. Name the error and explain why the trial balance may still agree.
Show the worked solution
- The transaction is posted to the wrong class of account: an error of principle.
- Both entries are still present and equal at $900.
- The debit and credit totals can agree even though Repairs and Equipment are misstated.
Answer This is an error of principle. Equal double-entry values can make the trial balance agree while the account classification and financial statements are wrong.
Try a topic test
Choose Easy, Normal or Difficult. Save your answers and open worked review after finishing.
Test this topic →From guided practice to a new situation
Write your answer and reasoning first. Use a hint only if you are stuck. The model solution is for self-checking; your written work is not automatically marked.
Classify each error: (a) $600 equipment is debited to Repairs; (b) a $400 invoice is entered as $40 in both accounts; (c) a sale is debited and credited to the correct accounts but both sides are reversed.
Give me a hint
Name the error from the account class, amount or direction that went wrong.
Compare my reasoning
- (a) Wrong class: error of principle.
- (b) Same wrong amount on both sides: error of original entry.
- (c) Correct accounts and amount but reversed sides: complete reversal.
(a) Principle; (b) original entry; (c) complete reversal.
Look for these in your work
- All three classes correct
- Reason for each given
- Trial-balance effect considered
A $180 cash sale is omitted completely. Separately, another expense is overstated by $90 while a different expense is understated by $90. Name both errors and explain their effect on trial-balance totals.
Give me a hint
For each case, ask whether both entries exist and whether errors offset.
Compare my reasoning
- The missing sale is a complete omission; both entries are absent.
- The equal and opposite expense errors are compensating errors.
- Either situation can leave debit and credit totals equal.
The sale is a complete omission; the expense errors are compensating. Neither necessarily changes the equality of the trial-balance totals.
Look for these in your work
- Omission classified
- Compensating error classified
- Totals effect explained
A supplier invoice is posted to the wrong supplier account, but the purchases account and total creditor control remain unchanged. Explain why a trial balance is not enough to detect it.
Give me a hint
Check what the trial balance totals: ledger debit and credit amounts, not the identity of each supplier balance.
Compare my reasoning
- The wrong supplier is still in the purchases-ledger class.
- The total debit and credit amounts can remain unchanged.
- Compare the supplier invoice with the individual account posting to identify the commission error.
This is an error of commission. The overall totals may still agree, so the supplier source document must be checked against the individual account.
Look for these in your work
- Error class correct
- Totals limitation explained
- Relevant evidence named
Common mistakes
- Calling every wrong account an error of principle
- Calling a single missing debit and credit a complete omission
- Assuming a wrong account always changes the trial-balance totals
What can you explain now?
A $250 credit sale is posted to the wrong customer's account, but Sales is correctly credited. Which error is this?
Compare with the explanation
Error of commission
The wrong personal account within the sales-ledger class was used.
After trying it yourself, choose your next review. This is your self-assessment.
Your review choice appears on Today. Sign in to sync it across devices.
Make it stick
Name the six errors that can leave a trial balance in agreement.
If you needed the solution, close it and solve the problem again from a blank page. A correct answer is stronger when you can explain the reason for each step.