The 7 Most Common Accounting Exam Mistakes—and How to Avoid Them

Accounting exams reward accuracy and clear presentation. Even when you understand the concepts, small mistakes can lose you marks unnecessarily. This guide walks you through the seven errors examiners see most often, so you can avoid them and improve your results.

Mixing up debits and credits

This is the single most common error in accounting exams. Students often confuse which accounts increase with a debit and which increase with a credit.

The rule: Assets and expenses increase with debits. Liabilities, capital and income increase with credits. Decreases work the opposite way.

To avoid this mistake, write out the accounting equation before you start: Assets = Liabilities + Capital. When posting journal entries, always ask yourself whether the account is increasing or decreasing, and which side of the equation it sits on.

Using incorrect formats for financial statements

Examiners award marks for proper presentation. If your income statement or balance sheet does not follow the required format, you lose marks even when your figures are correct.

Key format requirements:

• Income statement: Revenue at the top, then cost of sales, gross profit, expenses, and net profit in that order
• Balance sheet: Assets section (non-current, then current), then capital and liabilities section
• Proper headings with the business name and statement type
• Correct terminology (for example, "non-current assets" not "fixed assets" for IFRS-based syllabuses)

Practise drawing up blank statement templates until you can reproduce them from memory. This saves time in the exam and ensures you never miss structural marks.

Forgetting year-end adjustments

Adjustments for accruals, prepayments, depreciation and bad debts are worth significant marks, yet students frequently overlook them or apply them incorrectly.

Common adjustment errors:

• Calculating depreciation but forgetting to record it in both the income statement and balance sheet
• Adding accruals to expenses instead of adding them
• Treating prepayments as expenses rather than reducing the expense
• Ignoring the instruction to write off a specific bad debt

Read the question twice and highlight every adjustment mentioned. Work through them systematically, one at a time, and tick them off as you complete them.

Not showing your workings

Many students write final answers without showing how they calculated them. When your answer is wrong, you score zero marks instead of earning partial credit for correct method.

Always show workings for:

• Cost of sales calculations (opening inventory + purchases – closing inventory)
• Depreciation (cost × rate, or cost – residual value ÷ useful life)
• Accruals and prepayments
• Adjustments to receivables and payables
• Ratios and percentages

Workings also help you spot your own mistakes. If a figure looks unusual, you can trace back through your calculation to find the error.

Failing to balance accounts properly

Ledger accounts must balance. Students often carry down balances on the wrong side or forget to total both sides before calculating the balance.

The correct process:

1. Add up the larger side of the account
2. Write that total on both sides
3. Insert a balancing figure on the smaller side to make both sides equal
4. Label it "Balance c/d" (carried down)
5. On the next line below the totals, write "Balance b/d" (brought down) on the opposite side

Double-check that your final balance makes logical sense. A bank account with a credit balance means an overdraft. Inventory should never have a credit balance.

Misreading the question requirements

Students lose marks by answering a different question from the one asked. You might prepare an income statement when the question asks for a statement of financial position, or calculate gross profit when net profit is required.

Before you start writing:

• Underline or highlight the command words (prepare, calculate, explain)
• Note the specific period (year ended, month of June)
• Check what format is required
• Identify which accounts or transactions to include

Spend the first two minutes of each question reading carefully and planning your approach. This prevents costly mistakes that waste your time.

Arithmetic errors and transposition mistakes

Simple calculation errors and copying figures incorrectly are surprisingly common under exam pressure.

Strategies to reduce arithmetic mistakes:

• Use a calculator for every calculation, even simple addition
• Write figures clearly, especially 1, 4, 7 and 9
• When copying figures from the question, point to each number as you write it
• Check that your trial balance actually balances before moving on
• Verify that assets equal capital plus liabilities in your balance sheet

Leave time at the end to scan your work for obvious errors, such as a missing zero or a figure in the wrong column.

Your next step

Choose three past papers and work through them, focusing specifically on these seven areas. Mark your own work using the mark scheme, and note which mistakes you make most often. Then practise those specific skills until they become automatic. Awareness of these common errors is your first defence against them.