Books of Prime Entry Exam Guide and Checklist

Every transaction in financial accounting follows a strict path: source document, book of prime entry, and finally, the double-entry ledgers. When you sit your accounting exam, examiners test whether you understand the flow of data, not just the math.

This guide breaks down every book of prime entry, the structure of the ledger system, and the posting rules you must know to secure full marks in your A Level Accounting papers.

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What Are Books of Prime Entry?

A book of prime entry (also known as a book of original entry or subsidiary day book) is the very first record where a transaction is listed before it is posted into double-entry ledger accounts.

Why Businesses Use Books of Prime Entry

• Reduces volume: Summarises hundreds of individual transactions into periodic totals, preventing general ledger clutter.
• Specialisation: Different team members can handle credit sales, credit purchases, and cash transactions simultaneously.
• Internal control: Provides an audit trail that links physical source documents directly to ledger balances.

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Core Books of Prime Entry and Their Source Documents

Examiners regularly ask you to identify the source document that initiates an entry. Commit these pairings to memory:

Book of Prime Entry	Nature of Transactions Recorded	Primary Source Document
Sales Journal	Credit sales of inventory only	Sales invoice issued to customer
Purchases Journal	Credit purchases of inventory only	Purchase invoice received from supplier
Sales Returns Journal	Goods returned by credit customers	Credit note issued to customer
Purchases Returns Journal	Goods returned to credit suppliers	Debit note issued / Credit note received
Cash Book	All bank and cash receipts and payments	Receipts, cheque counterfoils, bank statements
Petty Cash Book	Small, incidental cash disbursements	Petty cash vouchers with till receipts
The General Journal	Non-regular transactions (assets, errors, adjustments)	Journal vouchers, invoices for non-current assets

Key Rule to Remember: Cash sales never go into the Sales Journal. Non-current assets bought on credit never go into the Purchases Journal. The Sales and Purchases journals record inventory on credit only.

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The Three Ledgers Explained

Once transactions are entered into books of prime entry, they are posted into the double-entry system. In modern accounting, accounts are organised across three distinct ledgers:

1. Sales Ledger (Receivables Ledger)

Contains the individual personal accounts of trade customers. It shows how much each customer owes at any point in time.

• Note: This ledger is traditionally a memorandum ledger (outside double-entry) if sales ledger control accounts are kept in the general ledger.

2. Purchases Ledger (Payables Ledger)

Contains the individual personal accounts of trade suppliers. It shows how much the business owes to each supplier.

• Note: Like the sales ledger, individual accounts serve primarily for tracking and credit control.

3. General Ledger (Nominal Ledger)

The true home of the double-entry system. It houses:

• Income accounts (e.g., Sales, Rent Received)
• Expense accounts (e.g., Purchases, Wages, Depreciation)
• Asset accounts (e.g., Non-current assets, Inventory, Bank)
• Liability accounts (e.g., Bank loans, Capital)
• Control accounts (Sales Ledger Control, Purchases Ledger Control)

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Step-by-Step Posting Rules

Understanding how figures move from day books into ledgers is a staple question type in any books of prime entry exam paper.

Posting from the Sales Journal

1. Individual Entries: Post each customer invoice to the Debit side of their personal account in the Sales Ledger (to increase what they owe).
2. Periodic Total: At the end of the week or month, transfer the total of the Sales Journal to the Credit side of the Sales Account in the General Ledger (and to the Debit side of the Sales Ledger Control Account, if maintained).

Posting from the Purchases Journal

1. Individual Entries: Post each supplier invoice to the Credit side of their personal account in the Purchases Ledger (to increase what the business owes).
2. Periodic Total: At the end of the period, transfer the total of the Purchases Journal to the Debit side of the Purchases Account in the General Ledger (and to the Credit side of the Purchases Ledger Control Account).

Posting from Returns Journals

• Sales Returns: Individual items credited to customer accounts; total debited to Sales Returns Account in the General Ledger.
• Purchases Returns: Individual items debited to supplier accounts; total credited to Purchases Returns Account in the General Ledger.

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The General Journal: When Do We Use It?

The General Journal (also called the Journal) records non-routine transactions that do not fit into the other six subsidiary books. Every entry requires a Debit, an equal Credit, and a brief narrative explaining the transaction.

Use the General Journal for:

1. Purchase and sale of non-current assets on credit
2. Correction of bookkeeping errors
3. Opening entries (starting a new business or bringing balances forward into a new system)
4. Year-end adjustments (accruals, prepayments, depreciation, irrecoverable debts, allowance for doubtful debts)
5. Transfers between accounts (contra entries between sales and purchases ledgers)

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Original Worked Example: Tariq Trading

Let us trace transactions through the books of prime entry and ledger accounts for Tariq, a wholesale trader, during June 2025.

Transactions:

• June 3: Sold goods on credit to Apex Retail: list price $1,200, subject to a 10% trade discount. (Invoice #401)
• June 8: Apex Retail returned damaged goods: list price $200 (from the June 3 order). (Credit Note #51)
• June 14: Purchased shop fixtures on credit from Modern Equipment Ltd for $3,400.
• June 28: Received a cheque from Apex Retail to settle their account in full, after deducting a 5% cash discount.

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Step 1: Prime Entry Records

Sales Journal

Date	Customer	Invoice No.	Amount ($)
June 3	Apex Retail ($1,200 − 10% discount)	#401	1,080
June 30	Transfer to Sales Account		1,080

Exam Tip: Trade discount is deducted on the invoice and is never entered as a separate double-entry account.

Sales Returns Journal

Date	Customer	Credit Note No.	Amount ($)
June 8	Apex Retail ($200 − 10% trade discount)	#51	180
June 30	Transfer to Sales Returns Account		180

Exam Tip: Returns must always reflect the trade discount originally applied!

The General Journal

Date	Details	Debit ($)	Credit ($)
June 14	Fixtures and Fittings Account	3,400
	Modern Equipment Ltd Account		3,400
	(Purchase of fixtures on credit from Modern Equipment Ltd)

Notice: This transaction did not enter the Purchases Journal because fixtures are capital expenditure (non-current assets), not trading inventory.

Cash Book (Extract: Receipts Side)

• Total balance owed by Apex Retail = $1,080 − $180 = $900.
• Cash discount offered = 5% of $900 = $45.
• Net cash received = $900 − $45 = $855.

Date	Details	Discount Allowed ($)	Bank ($)
June 28	Apex Retail	45	855

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Step 2: Ledger Postings

Sales Ledger: Apex Retail Account

Date     Details       $    Date     Details           $
June 3   Sales       1,080  June 8   Sales Returns    180
                            June 28  Bank             855
                            June 28  Discount Allowed  45
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                     1,080                          1,080

(The account is cleared with zero balance.)

General Ledger Accounts

• Sales Account: Credit $1,080 on June 30.
• Sales Returns Account: Debit $180 on June 30.
• Discount Allowed Account: Debit $45 on June 30.
• Bank Account: Debit $855 on June 28.
• Fixtures and Fittings Account: Debit $3,400 on June 14.
• Modern Equipment Ltd Account: Credit $3,400 on June 14.

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Books of Prime Entry Exam Checklist

Before walking into your exam, ensure you can tick off each item:

• Can you distinguish Trade Discount from Cash Discount?
  • Trade discount: Given for bulk purchases or customer relationship; deducted directly on invoices; does not appear in ledger accounts.
  • Cash (settlement) discount: Given for prompt payment within a time limit; recorded in the Cash Book and posted to Discount Allowed/Received accounts.
• Do you know where non-current asset transactions are recorded?
  • Bought for cash/bank $\rightarrow$ Cash Book.
  • Bought on credit $\rightarrow$ General Journal.
• Can you write a General Journal narrative?
  • Concise sentence stating the reason for the entry.
• Do you know the double entry for discount columns in the Cash Book?
  • Total of Discount Allowed column $\rightarrow$ Debit of Discount Allowed Account.
  • Total of Discount Received column $\rightarrow$ Credit of Discount Received Account.
• Are you clear on debit notes vs credit notes?
  • A buyer sends a debit note to request a reduction.
  • A seller sends a credit note to confirm and authorize the reduction.

If you are preparing for exams or resits, explore our detailed study resources or learn more about structured guidance with a Cambridge A Level Accounting tutor.

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4 Common Exam Pitfalls to Avoid

1. Entering credit purchases of equipment in the Purchases Journal.
   • Correction: Purchases Journal is reserved solely for goods bought for resale.
2. Forgetting trade discount on returns.
   • Correction: If an item had a 15% trade discount on the original invoice, the credit note and sales returns entry must also be reduced by 15%.
3. Reversing debit and credit note roles.
   • Correction: The supplier issues the credit note. It acts as the official source document for the sales returns book (for the seller) and purchases returns book (for the buyer).
4. Treating memorandum ledgers as double entry.
   • Correction: Individual accounts in the Sales and Purchases ledgers provide subsidiary detail. Double entry is completed via the General Ledger totals and control accounts.