Inventory bookkeeping for retail clients is one of the areas where poor processes have the most visible financial impact. The value of closing stock directly affects the cost of goods sold figure, which flows into gross profit, which determines taxable income. Get it wrong by $20,000 and the client's tax position changes materially.
This guide covers the core concepts of inventory valuation, the most common inventory bookkeeping errors, and how to structure a process that keeps the stock records accurate throughout the year.
The Inventory Equation
The fundamental relationship in retail bookkeeping:
Cost of Goods Sold = Opening Stock + Purchases − Closing Stock
If opening stock is $50,000 and purchases during the year total $300,000, then the cost of the goods available for sale is $350,000. If the closing stocktake values the remaining inventory at $60,000, then COGS for the year is $290,000.
The closing stock figure is not derived from the accounting software — it comes from a physical stocktake. The software records what was purchased; the physical count records what's actually there. The difference (shrinkage, breakage, theft, errors) is the stock loss, which flows into COGS.
Inventory Valuation Methods
Australian tax law allows businesses to value inventory at the end of the year using:
- Cost price: The actual purchase price of the goods (plus freight, duties, and other directly attributable costs)
- Market selling value: The amount the goods would realise if sold
- Replacement price: The current cost to replace the goods
The business can choose a different method for each class of inventory and can change from year to year — with the important constraint that the method chosen must produce the lower of cost and net realisable value, which is consistent with accounting standards.
For most retail businesses, cost price is the standard approach. Market selling value may be used for damaged, obsolete, or slow-moving stock where the market value has fallen below cost.
For GST purposes, the value of closing stock used in the tax calculation uses the same valuation method.
FIFO vs Weighted Average Cost
For businesses with goods that have the same type but different cost prices (e.g., a retailer who bought widgets at $5.00 in July and $6.00 in December), a cost flow assumption is needed to determine which cost attaches to sold and remaining inventory.
FIFO (First In, First Out): Assumes the earliest-purchased goods are sold first. In a period of rising prices, FIFO produces a higher closing stock value (the remaining stock is at the higher recent prices) and lower COGS.
Weighted Average Cost: Calculates an average cost per unit across all purchases during the period. Less sensitive to price fluctuations.
The key is consistency — once a method is chosen and applied, changing it requires the ATO's approval and must be disclosed. Most small retail businesses use weighted average cost through their POS or inventory management system.
The EOFY Stocktake
The most important inventory event of the year is the 30 June stocktake. The count must be conducted as close to 30 June as possible to produce a year-end inventory value.
Stocktake process:
- Freeze stock movements during the count (no receiving or dispatch)
- Count all items by location, category, and SKU
- Record counts independently by two people where possible (or at minimum, have a reconciliation check)
- Compare count to the perpetual inventory in your software — investigate significant variances
- Value the counted items at cost (or market value for impaired stock)
- Record the adjustment in the accounts
Accounting entry for stocktake adjustment:
- If physical count is LOWER than the perpetual inventory (shrinkage):
- Debit: Stock shrinkage / loss expense
- Credit: Inventory (reduce the balance sheet value)
- If physical count is HIGHER (overcount or receiving error):
- Debit: Inventory
- Credit: Stock gain (rare — usually indicates a receiving error)
WIP and Work-in-Progress for Product Businesses
For clients who manufacture or assemble products (rather than purely resell), the inventory has three stages: raw materials, work-in-progress (WIP), and finished goods. Each stage has its own accounting treatment.
WIP represents the cost of goods that have been started but not yet completed at year-end — the materials consumed plus the labour and overheads applied to that point. Valuing WIP requires a more detailed cost accounting approach than is typical for pure resellers.
For small manufacturers, a simplified approach that estimates the proportion of completion and applies that to the unit cost is generally acceptable, provided it's applied consistently.
Integrating POS Systems with Accounting Software
Most retail clients use a point-of-sale (POS) system that tracks inventory movements in real time. The bookkeeping challenge is getting POS data into the accounting software accurately.
Common integration issues:
- POS records sales at the retail price; the accounting software needs the COGS figure (often derived from a separate cost database)
- Returns and exchanges need to be handled correctly in both systems — a return increases inventory and reduces revenue, and the accounting entries must reflect both
- POS systems often generate daily or weekly summary data rather than transaction-level data, which can make reconciliation more difficult
Before onboarding a retail client, understand how their POS integrates (or doesn't) with their accounting software and establish a clear reconciliation process for the POS-to-accounting interface.
Slow-Moving and Obsolete Stock
Slow-moving stock is a profitability drain that's often visible in the accounts but not addressed because it requires a write-down that reduces profit. Help clients understand that writing down obsolete stock to its net realisable value (what it will actually sell for) is appropriate accounting treatment and creates a legitimate tax deduction.
The write-down process:
- Identify stock whose market value has fallen below cost (seasonal, damaged, discontinued)
- Determine the expected realisable value (what a clearance sale would yield)
- Write down the inventory from cost to realisable value
- Record the write-down as an expense (stock impairment or stock write-down)
The write-down must be supportable — the ATO may ask for evidence that the stock was genuinely obsolete or impaired rather than just underperforming.
Building a Year-Round Inventory Reconciliation Process
Monthly or quarterly stocktakes (even partial counts by category) catch problems before they compound. A full count at EOFY only reveals the cumulative effect of a year's worth of errors — a quarterly cycle identifies issues while they're still manageable.
At minimum, run a reconciliation of the perpetual inventory against purchases and sales every quarter. If the implied shrinkage rate is significantly above industry norms, investigate before it becomes a large write-off at year-end.
For retail clients, the difference between excellent and poor inventory bookkeeping is largely the difference between structured, regular reconciliation and a once-a-year catch-up in June. The structured approach produces accurate management accounts throughout the year and a clean, defensible EOFY position.