Same purchases, same sales, same cash, and 2 gross margins 4 and a half points apart. The difference is not a mistake. It is the valuation method, and most businesses chose theirs by accident.
Nobody argues about revenue. It is on the invoices. Nobody argues much about purchases. They are on the bills. The number everybody takes on trust is the one in between: the value of what was sold, which is the value of what came in, minus the value of what is still on the shelf. Closing stock is the plug that turns purchases into cost of sales, and how it is valued decides what gross margin looks like.
That is not a rounding issue. In a business where stock turns 4 times a year, the closing stock is a quarter of a year's purchases, and a valuation method that shifts it by 5 percent moves the year's margin by more than most businesses' entire net profit. And it does it without a single transaction being wrong.
A valuation method does not change what was bought or sold. It decides which purchase price attaches to which sale, and therefore how much of the year's buying is expensed now and how much waits in stock. The cash is the same. The margin is not.
A trading business buys one product twice in a month and sells some of it. Illustrative figures.
| Movement | Quantity | Price | Value |
|---|---|---|---|
| Bought, 3rd | 1,000 | 100 | 100,000 |
| Bought, 18th | 1,000 | 120 | 120,000 |
| Sold, through the month | 1,200 | 150 | 180,000 |
Revenue is 180,000 under any method. 800 units are left. The question is what those 800 units are worth, and the answer depends on which 1,200 units are deemed to have gone out.
| First in, first out | Moving average | |
|---|---|---|
| Units sold are valued at | 1,000 at 100, then 200 at 120 | 1,200 at 110 |
| Cost of sales | 124,000 | 132,000 |
| Gross margin | 56,000 | 48,000 |
| Gross margin percent | 31.1% | 26.7% |
| Closing stock, 800 units | 96,000 | 88,000 |
Same purchases, same sales, same cash. 8,000 of margin, 4 and a half points, sitting in the choice of method. In a falling market the sign reverses.
Neither figure is wrong. First in, first out says the old cheap stock went out first, so the expensive stock is still here and the margin on this month's sales was fat. Moving average says every unit sold carried the blended cost, so the margin is thinner and the shelf is cheaper. Over the life of the stock the 2 methods converge: the 8,000 is timing. But management accounts are read month by month, and a manager paid on this month's margin has 8,000 reasons to care which method the business uses.
Each sale consumes the oldest stock still on hand at its own purchase price. Closing stock is always valued at the most recent prices, which is why the balance sheet likes it. The cost of sales lags the market, which is why the margin flatters in a rising market and punishes in a falling one. Needs the stock ledger to hold layers, one per receipt.
Every receipt recomputes one average price for the item, and every issue goes out at that price. Closing stock and cost of sales carry the same price, so the margin reacts to the market at once and smoothly. Needs only one price per item, which is why most trading ERPs default to it. The average must be recomputed on every receipt, not once a month.
Every unit is held at a price fixed in advance, and the difference between that and what was paid is taken to the profit and loss account as a variance the day the goods arrive. Closing stock never moves with the market. The right method for a manufacturer that wants its buyers and its shop floor measured separately, and the wrong one for a trader whose whole business is the market price.
A fourth, last in first out, is not permitted under Indian accounting standards or under IFRS, and is mentioned here only because somebody's spreadsheet is still doing it.
Businesses that track lots, for expiry, for recall, or because the customer demands a batch number on the delivery challan, often assume the lot number also decides the valuation. It should not, unless the business has deliberately chosen that it should.
Lot traceability answers: which units went to which customer. Valuation answers: what did the units that went out cost. These are separate questions with separate answers. A pharmaceutical distributor that ships the nearest expiry lot first, which may be the lot bought last at the highest price, is right to do so physically and is still free to value its issues at moving average. The alternative, valuing each issue at the specific cost of the lot that physically left, is called specific identification, and it is the correct method for a car dealer or a jeweller, where each unit is a unique, high value item. For 2,000 cartons of the same tablet it produces a margin that moves with the picker's choice of shelf.
Decide the valuation method by what the item is, not by whether it carries a lot number. Lots decide traceability. The method decides cost. A system that forces the 2 together will give you a gross margin that depends on which pallet was nearest the door.
Imported goods arrive with a supplier invoice, a freight bill, an insurance charge, customs duty, and a clearing agent's fee, typically from 5 different parties on 5 different dates. If the stock is valued at the supplier invoice alone, the other 4 land in expenses when they arrive and the margin on that product is overstated by the whole of them. On a container where freight and duty add 18 percent to the supplier price, that is 18 percent of margin that is not there.
The landed cost has to be spread across the units that came in, by value or by weight or by volume as the charge dictates, and it has to be spread before the units are sold. The difficulty is that the freight bill often arrives 3 weeks after the goods, by which time half of them have gone out at the wrong cost. A system that allows a charge to be added to a receipt already booked, and pushes the difference through cost of sales for the units already sold and through stock for the units still held, is the only kind that gets this right without a month end journal nobody understands.
Three timing problems produce most of the wrong margins that get found at the audit.
Every method above values stock at cost. The accounting standard adds a ceiling: stock is carried at the lower of cost and what it can be sold for, less the cost of selling it. That ceiling bites in 3 places.
Niyantrak Consulting helps trading and manufacturing businesses choose a valuation method they can defend, and then makes the stock ledger and the general ledger agree, which is usually the larger job. Most of the margin surprises we are asked to explain turn out to be valuation and timing, not price.
Niyantrak ERP was built with this in mind. Stock is valued at moving average recomputed on every receipt, or at standard cost for manufacturers, with the price difference posted the day the goods arrive. Receipts hit stock before the bill, through a goods received not invoiced account that the bill clears. Landed cost charges spread across a receipt, including one already partly sold. Lots carry expiry and traceability without dictating the cost. And every item shows when it last moved, so the non moving review is a screen, not a project. It runs on your own computer, and nothing leaves the building.
A short conversation is usually enough to tell whether the valuation method, the landed cost, or the timing of receipts and bills is what moved it. Niyantrak Consulting works with trading and manufacturing businesses on exactly this.