Correct Option: C. When a buyer is under or over charged Detailed Explanation: Understanding Credit and Debit Notes: Credit and debit notes are essential documents in accounting that help adjust transactions between buyers and sellers. They are used to correct errors in invoices or to account for returns of goods.

1. Credit Note:
2. A credit note is issued by a seller to a buyer, indicating a reduction in the amount owed by the buyer. This can occur when:
   • The buyer has been overcharged.
   • Goods are returned due to defects or other reasons.
   • Discounts or allowances are granted after the invoice has been issued.
3. Debit Note:
4. A debit note is issued by a buyer to a seller, indicating an increase in the amount owed. This can occur when:
   • The buyer has been undercharged.
   • Additional charges need to be accounted for after the initial invoice.

Why Option C is Correct: - Option C states that credit and debit notes are used when a buyer is under or overcharged. This is the primary reason for issuing these notes: - If a buyer is overcharged, a credit note is issued to reduce the amount owed. - If a buyer is undercharged, a debit note is issued to increase the amount owed. - This adjustment process ensures that both parties have accurate records and that the financial statements reflect the true financial position. Why Other Options are Incorrect: Option A: When goods are received from supplier - This option is incorrect because the mere act of receiving goods does not necessitate the issuance of credit or debit notes. Credit and debit notes are specifically related to adjustments in billing, not the receipt of goods. When goods are received, an invoice is typically matched with the goods received note, but no adjustments are made unless there is a discrepancy in pricing or quantity. Option B: When a trial balance is extracted - This option is also incorrect. A trial balance is a report that lists the balances of all accounts in the general ledger at a specific point in time. It is used to ensure that total debits equal total credits. The extraction of a trial balance does not involve any transactions that would require credit or debit notes. It is a summary of account balances, not a transaction adjustment. Option D: When goods are sold to a buyer - This option is misleading. While selling goods does involve issuing an invoice, it does not directly lead to the issuance of credit or debit notes unless there is an issue with the invoice (such as overcharging or undercharging). The sale itself is a standard transaction and does not require adjustments unless there are discrepancies. Common Pitfalls:

• Confusing the issuance of credit and debit notes with standard invoicing processes.
• Not recognizing that credit and debit notes are specifically for correcting billing errors or adjustments, not for routine transactions.
• Overlooking the importance of accurate record-keeping to avoid the need for credit and debit notes.

Revision Summary:

• Credit notes reduce the amount owed by a buyer, while debit notes increase it.
• These notes are primarily used to correct billing errors, such as overcharging or undercharging.
• Receiving goods or extracting a trial balance does not necessitate credit or debit notes.
• Accurate invoicing and record-keeping are crucial to minimize the need for adjustments.