§-Syllabus dot point

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How does the perpetual inventory system record purchases, sales and cost of goods sold?

Record inventory transactions under the perpetual system and reconcile to a stocktake.

Recording purchases, sales and cost of goods sold under the perpetual inventory system, including the two entries per sale and the inventory loss on stocktake.

Generated by Claude Opus 4.88 min answerUpdated 2026-06-02

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What this dot point is asking

The TASC course records inventory using the perpetual system, with the cost of goods sold given to you. Perpetual means continuous: every movement of stock is recorded as it happens, so the Inventory ledger account always shows what should be on hand. This contrasts with the periodic system, where inventory is only counted at period end.

Recording purchases

When goods are bought for resale, the cost goes straight into the asset account Inventory, not a Purchases account. A credit purchase of stock is recorded as debit Inventory, debit GST clearing, and credit Creditors Control for the total.

Recording a sale: two entries

Because the system tracks both the sale and the cost at the moment of sale, every sale has two parts.

Entry 1 records the revenue: debit Cash or Debtors, credit Sales, credit GST clearing.
Entry 2 records the cost: debit Cost of Goods Sold (an expense), credit Inventory.

Inventory loss and the stocktake

Even with continuous records, a physical count (stocktake) may find less stock than the ledger shows, because of theft, breakage or errors. The difference is an inventory loss. The recorded balance is brought down to the counted figure with an adjustment.

Worked example

A purchase, a sale and a stocktake

A trader using the perpetual system buys stock on credit, makes a cash sale, and then discovers a discrepancy when the stock is counted at month end.

Step 1: Record the purchase of stock

When goods are bought for resale, the cost is an asset, not an expense, so Inventory is debited. GST paid on the purchase is an input tax credit, so it is debited to the GST clearing account. The full GST-inclusive amount owed to the supplier is credited to Creditors Control:

Account	Debit	Credit
Inventory	$4,000
GST clearing	$400
Creditors Control		$4,400

Step 2: Record the sale (entry 1 - revenue)

The first of the two required entries records what the customer paid. Cash is debited for the full GST-inclusive receipt of $2\,200$ . Sales is credited for the GST-exclusive base of $2\,000$ , and GST clearing is credited for the $200$ GST collected on behalf of the ATO. Note that the GST inside a GST-inclusive price is the total divided by 11:

\text{GST} = \frac{2{,}200}{11} = \$200 \quad \text{Sales (base)} = 2{,}200 - 200 = \$2{,}000

Account	Debit	Credit
Cash	$2,200
Sales		$2,000
GST clearing		$200

Step 3: Record the sale (entry 2 - cost)

The second entry removes the cost of the goods from Inventory and records it as an expense. Without this entry, Inventory would remain overstated and Cost of Goods Sold would be understated, making gross profit too high:

Account	Debit	Credit
Cost of Goods Sold	$1,300
Inventory		$1,300

Step 4: Calculate the Inventory ledger balance before the stocktake

The Inventory account moves with every purchase and every sale. Adding the purchase and subtracting the cost of the sale gives the balance the ledger says should be on hand:

\text{Ledger balance} = 1{,}000 + 4{,}000 - 1{,}300 = \$3{,}700

Step 5: Record the inventory loss found at stocktake

The physical count reveals only $3\,500$ on hand, which is $200$ less than the ledger shows. The shortfall is recorded as an expense (Inventory Loss) and Inventory is credited to reduce the asset to the counted figure:

\text{Inventory loss} = 3{,}700 - 3{,}500 = \$200

Account	Debit	Credit
Inventory Loss	$200
Inventory		$200

After this adjustment the Inventory account shows $3\,500$ , matching the physical count.

Final answer: Inventory after the stocktake adjustment is $\$3{,}500$ ; the loss of $\$200$ is expensed as Inventory Loss.

Sales returns and purchase returns

Returns also need careful handling under the perpetual system. When a customer returns goods, reverse both the revenue entry (debit Sales Returns, debit GST clearing, credit Cash or Debtors) and the cost entry (debit Inventory, credit Cost of Goods Sold), because the goods physically come back into stock. When the business returns goods to a supplier, reverse the original purchase (debit Creditors Control, credit Inventory, credit GST clearing). Forgetting the cost side of a sales return leaves Inventory understated and overstates cost of goods sold.

Cost flow and the value recorded

The amount debited to Cost of Goods Sold on each sale is the cost of those particular goods, which the TASC course normally provides. In practice a business needs a cost-flow assumption (such as first-in-first-out) to decide which cost applies when identical items were bought at different prices, but at this level you are usually given the cost per sale and focus on the recording. The key idea is that Inventory is always carried at cost, never at selling price, so the asset and the eventual gross profit are measured reliably.

Inventory and gross profit

Because the perpetual system records cost of goods sold continuously, gross profit (Sales less Cost of Goods Sold) can be read at any time, not just at period end. An inventory loss found at stocktake is treated as a separate expense rather than buried in cost of goods sold, which keeps the gross profit margin meaningful and highlights losses to management. This direct link to gross profit is why accurate inventory recording matters for the income statement and the efficiency ratios studied later.

Why this matters

Perpetual recording lets a business know its stock position and gross profit at any time without waiting for a count, which supports reordering and theft detection. Exam questions reward the second (cost) entry on every sale and the correct treatment of an inventory loss, both of which directly affect the gross profit reported later.

Exam-style practice questions

Practice questions written in the style of TASC exam questions on this dot point, with worked answer explainers. The year tag is the paper they imitate, not the source.

TCE 20228 marksA trader using the perpetual system records the following in May: bought inventory on credit, base

9\,000 plus GST; sold goods for

7\,700 cash (including GST) that had cost

4\,500; a customer returned goods sold for

1\,100 (including GST) that had cost

650. Opening Inventory was

3\,000. Record the journal entries for each event and calculate the closing balance of the Inventory account before any stocktake.

Show worked answer →

Each sale and sales return needs two entries under the perpetual system.

Purchase: Debit Inventory $9\,000$ ; Debit GST clearing $900$ ; Credit Creditors Control $9\,900$ .

Sale, revenue entry: Debit Cash $7\,700$ ; Credit Sales $7\,000$ ; Credit GST clearing $700$ . Cost entry: Debit Cost of Goods Sold $4\,500$ ; Credit Inventory $4\,500$ .

Sales return, reverse revenue: Debit Sales Returns $1\,000$ ; Debit GST clearing $100$ ; Credit Cash (or Debtors) $1\,100$ . Reverse cost (goods come back into stock): Debit Inventory $650$ ; Credit Cost of Goods Sold $650$ .

Inventory account: $3\,000 + 9\,000 - 4\,500 + 650 = \$8\,150$ .

Markers reward the GST split on the purchase and sale, both entries per sale, the two-part sales return that restores cost to Inventory, and the correct closing Inventory balance.

TCE 20234 marksExplain the difference between the perpetual and periodic inventory systems and give one advantage of the perpetual system for management decision-making.

Show worked answer →

A full 4 mark answer contrasts the two systems and links perpetual to a decision.

Under the perpetual system the Inventory account is updated continuously, with a cost entry made every time goods are sold, so the ledger shows the cost of goods on hand at any moment. Under the periodic system Inventory is not updated for each sale; cost of goods sold and closing inventory are only determined at period end after a physical stocktake.

An advantage of perpetual recording for management is that it provides up-to-date stock and gross profit figures at any time, which supports timely reordering, identifies slow-moving lines, and allows inventory losses (theft or error) to be detected by comparing the ledger to a stocktake. Markers reward the continuous-versus-period-end contrast, the point that perpetual records cost per sale, and a valid management advantage.