Stock variation: how to read and record it

Updated March 2026 - Stock variation directly influences how consumption, margin and operational performance are read. In 2026, it is both a year-end closing line and an indicator of operational control quality. Understanding it correctly — and recording it accurately — matters both for financial reporting and for management decision-making.

Stock variation measures the difference between the opening stock (inventory at the start of the period) and the closing stock (inventory at the end of the period), allowing a more accurate reading of:

• actual consumption: if purchases are recorded on an accruals basis but stock has increased, the actual consumption is lower than the purchase figure suggests — the closing stock has absorbed part of the expense;
• true gross margin: the correct cost of goods sold (or consumed) depends on adjusting for stock movements — a margin calculation that ignores stock variation produces a misleading profitability picture;
• produced or destocked production: in manufacturing or production contexts, stock variation also captures the change in work-in-progress and finished goods inventory;
• inventory anomalies: unexplained or unexpected stock variations can signal inventory management problems, theft, waste, obsolete stock or counting errors.

A poorly measured stock variation corrupts several downstream accounting outputs:

• the operating result is directly affected — overstated closing stock reduces consumption and inflates profit; understated closing stock does the reverse;
• the gross margin becomes unreliable if stock variation is not correctly applied to cost of goods sold;
• the activity analysis loses coherence — decisions based on margin data that does not reflect actual consumption lead to wrong pricing, purchasing and production conclusions;
• the audit and compliance risk increases — statutory auditors and tax inspections typically review inventory counting procedures and closing stock valuation as priority areas.

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Under the French General Chart of Accounts (Plan Comptable General — PCG), stock variation is structured around specific accounts linking Class 3 (stock assets on the balance sheet) with Classes 6 and 7 (charges and products in the income statement).

Accounts 603: variation of purchased stock#

Accounts 603 record the variation of purchased goods stock, broken down into three main sub-accounts:

• 6031 — Variation of raw materials stock (linked to account 31)
• 6032 — Variation of other supplies stock (linked to account 32)
• 6037 — Variation of merchandise stock (linked to account 37)

The balance of these accounts adjusts the corresponding purchases. A credit balance indicates a stock increase (purchases exceeding consumption), which reduces the period's charges. A debit balance indicates a stock decrease (consumption exceeding purchases), which increases charges.

Accounts 713: variation of production stock#

For manufacturing or craft businesses that produce goods, stock variation is recorded as income through accounts 713:

• 7133 — Variation of work-in-progress for goods
• 7134 — Variation of work-in-progress for services
• 7135 — Variation of finished goods stock

Here the logic is reversed: an increase in manufactured product stock increases the period's production, because the company has created value that has not yet been sold.

The choice of valuation method directly impacts the stock variation amount. The PCG authorises several approaches, each with different consequences for the reported result.

FIFO (first in, first out)#

The FIFO method assumes that the first items entering stock are the first consumed or sold. During inflationary periods, this method tends to value outgoing items at older, usually lower costs. Closing stock is therefore valued at the most recent costs, which approximates market value.

This approach is particularly suited to perishable products or items subject to rapid obsolescence. It is also the preferred method under IFRS standards (IAS 2), which facilitates reconciliation for consolidated groups.

Weighted Average Unit Cost (CUMP)#

The CUMP smooths price fluctuations by calculating an average cost across all entries:

CUMP = (Opening stock value + Entry value) / (Opening stock quantity + Entry quantity)

This method, widely used in French SMEs, provides a stabilised view of cost prices. It limits the effects of one-off price fluctuations on the income statement and simplifies account reading. The CUMP can be calculated periodically (end of month, end of quarter) or after each entry.

Standard cost#

Some industrial companies use a predetermined standard cost with variance analysis at period end. This approach is useful for internal management but requires adjustments for general accounting purposes.

Whichever method is chosen, the PCG requires it to be applied consistently from one period to the next. Any change in method must be justified and disclosed in the notes to the annual accounts.

Stock variation accounting entries occur during inventory operations at the close of each period. Two symmetrical entries are required.

Reversing the opening stock#

On the first day of the period, the previous period's stock is cancelled by debiting the variation account and crediting the stock account:

• Debit 6031 (or 6037) / Credit 31 (or 37): opening stock amount

This entry reintegrates the opening stock as a charge, since it was recorded as an asset during the previous closing.

Recording the closing stock#

At the end of the period, after the physical inventory count, the new stock is recorded:

• Debit 31 (or 37) / Credit 6031 (or 6037): closing stock amount

The net balance of account 603 then represents the period's stock variation. If closing stock exceeds opening stock, account 603 shows a credit balance that reduces charges. Otherwise, the debit balance increases the period's charges.

For production stock, entries are symmetrical but pass through accounts 713 as income.

Stock variation has a direct and immediate impact on the accounting result and, consequently, on the company's taxable income.

An increase in raw materials or merchandise stock (credit balance on accounts 603) reduces the period's charges and mechanically increases taxable income. Conversely, a stock decrease (débit balance) increases charges and reduces the result.

For production stock, the effect is reversed: an increase in finished goods stock (credit balance on accounts 713) increases the period's production and therefore taxable income.

The French tax authorities pay particular attention to stock valuation during accounting verification audits. An abnormal stock variation, a valuation method changed without justification, or a physical inventory that is insufficiently documented are all areas of weakness. Unexplained inventory discrepancies may be reclassified as taxable income or omitted invoicing.

Several recurring errors distort the stock variation calculation and can have significant consequences.

Incomplete or inaccurate physical inventory. Partial counting, inconsistent units of measurement or misidentified products directly contaminate the closing stock valuation. The inventory must be exhaustive, conducted at a clear cut-off date and properly documented.

Lack of rigorous period cut-off. Deliveries received before closing but invoiced afterwards, or vice versa, must be allocated to the correct period. Without rigorous cut-off, stock variation includes operations that do not concern it.

Undocumented changes in valuation method. Switching from FIFO to CUMP (or vice versa) without justification in the notes constitutes an accounting irregularity. The tax authorities may challenge the results of the affected periods.

Confusing stock variation with depreciation. Obsolete stock or stock whose net realisable value is below entry cost must be subject to a depreciation entry (accounts 39), separate from the stock variation itself.

Hayot Expertise advice: stock variation is not just a technical closing line. It often tells the story of how well the inventory process is managed — the quality of the physical count, the consistency of the valuation method and the discipline of the cut-off procedures. A company that tracks its stock variations month by month, not just at the annual closing, has a real advantage in managing purchases and anticipating cash flow pressures.

We recommend systematically checking four dimensions:

1. Physical inventory reliability: is the count exhaustive? Are units of measurement consistent? Are discrepancies between theoretical and physical stock analysed and justified?
2. The valuation method: is it applied consistently? Do entry costs include ancillary expenses (transport, customs, handling) in accordance with the PCG?
3. End-of-period cut-off: are in-transit deliveries allocated to the correct period? Are credits and returns properly accounted for?
4. The link between stock variation, purchases and margin: is the gross margin calculated after applying stock variation consistent with operational reality? Unexplained discrepancies should raise alarms.

We can help you make this line more reliable and connect it to your operational performance monitoring.

Discover our accounting and operational steering support

In 2026, stock variation remains a key closing and steering line. When correctly calculated, it explains operational performance accurately. When incorrectly measured, it distorts it — consistently misleading management decisions across pricing, purchasing and profitability analysis. Between the demands of the tax authorities, the digitalisation of accounting tools and the need for reliable financial data, companies have every interest in treating this subject with rigour throughout the period, not just at the annual inventory.