Inventory is not depreciated like fixed assets — it is carried on your books at cost and only written down when its value drops below what you paid. Depreciation, in the strict accounting sense, applies to long-lived assets you use in the business: equipment, vehicles, buildings, fixtures. Inventory is a current asset you intend to sell, so its cost sits in an asset account until the item sells (becoming cost of goods sold) or until it loses value through damage, spoilage, obsolescence, or a market price drop — at which point you record an inventory write-down, not depreciation. For an operator, the practical lesson is the same one depreciation teaches: the value of what you own can quietly erode, and if you don't recognize it in time, you overstate profit, overpay tax in the wrong period, and get blindsided when you try to turn that inventory back into cash. This guide explains how inventory valuation actually works, when a write-down is required, how it hits your cash flow, and how to fund inventory purchases when working capital is tight.
Key takeaways
- Inventory is not depreciated on a schedule like equipment — it is held at cost and written down only when its value falls below cost.
- The governing rule is lower of cost or net realizable value (LCNRV): carry inventory at the lower of what you paid or what you can sell it for, net of selling costs.
- Write-downs are triggered by obsolescence, spoilage, expiration, physical damage, market price drops, or shrinkage — not by the passage of time.
- Your cost method (FIFO, LIFO, weighted average, specific ID) shapes reported profit, tax, and the collateral value lenders see.
- Falling inventory turnover on specific SKUs is the earliest warning that value is eroding — monitor it monthly, not at year-end.
- A write-down lowers current-period profit and taxable income and restates inventory at a realizable value; it never writes value up.
- Inventory loss is fundamentally a cash-flow problem: the cash left the business at purchase, and dead stock ties up working capital you need to reorder.
Depreciation vs. inventory write-downs: why the difference matters
The words get used interchangeably in conversation, but the IRS and GAAP treat them very differently, and getting it wrong distorts your financials.
- Depreciation spreads the cost of a fixed asset — something you use to run the business over multiple years — across its useful life. A commercial refrigerator, a delivery van, a POS system. You take a portion of the cost as an expense each year.
- Inventory is what you buy or make to sell. It is not depreciated on a schedule. It stays on the balance sheet at cost until it sells or until its value falls, when you record a write-down (a partial loss) or a write-off (a total loss).
The reason this matters: depreciation is predictable and time-based; inventory loss is event-based and often invisible until you count it. A restaurant owner knows the oven loses value every year. The same owner may not realize that $8,000 of specialty ingredients quietly expired in the back of the walk-in. Both are real losses of asset value — but only one shows up automatically. Inventory demands active monitoring.
How inventory is valued: cost methods that shape your numbers
Before you can measure how much value inventory has lost, you have to know how it's valued in the first place. The method you choose affects reported profit, tax, and the collateral value a lender or funder sees.
- FIFO (First-In, First-Out): assumes the oldest stock sells first. In a rising-cost environment, this leaves newer, higher-cost inventory on the books — higher reported profit, higher tax, but a balance sheet closer to current replacement cost.
- LIFO (Last-In, First-Out): assumes newest stock sells first. In inflation, this raises cost of goods sold and lowers taxable profit — but leaves older, cheaper costs on the balance sheet and is not permitted under international standards.
- Weighted average cost: blends all units into one average cost. Simple, smooths out price swings, common in software-run retail and distribution.
- Specific identification: tracks each item individually. Used for high-value, low-volume goods — jewelry, vehicles, custom equipment.
Whatever method you use, the governing rule for recognizing lost value is lower of cost or net realizable value (LCNRV): inventory is carried at the lower of what you paid or what you can realistically sell it for, minus the cost to sell it. When net realizable value drops below cost, you write the difference down.
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When you must write inventory down (and how to spot it early)
A write-down is required when inventory can no longer be sold for at least its carrying cost. The common triggers:
- Obsolescence: technology, fashion, or model-year changes strand product. Last season's phone cases, superseded parts, discontinued SKUs.
- Spoilage and expiration: food, cosmetics, pharmaceuticals, and any dated goods.
- Physical damage: water, breakage, mishandling in storage or transit.
- Market price declines: a competitor or supplier resets the going rate below your cost.
- Shrinkage: theft, miscounts, and administrative error — caught only by physical counts.
The early-warning tool is your inventory turnover ratio (cost of goods sold divided by average inventory). Slowing turnover on specific SKUs is usually the first sign that value is eroding before an accountant ever flags it. Aging reports — grouping stock by how long it's sat — turn that signal into a to-do list: discount, bundle, liquidate, or write down. Running these reports monthly instead of at year-end is the single highest-leverage habit for protecting inventory value.
A worked example: how a write-down flows through your books
Consider a fictional home-goods retailer reviewing its year-end stock. The figures below are illustrative — for example only — to show the mechanics, not a benchmark for any real business.
| SKU / lot | Units | Cost per unit | Carrying value (at cost) | Net realizable value per unit | Write-down recorded |
|---|---|---|---|---|---|
| Prior-season lamps | 120 | $45 | $5,400 | $30 | $1,800 |
| Discontinued rug line | 60 | $110 | $6,600 | $70 | $2,400 |
| Water-damaged bedding | 200 | $25 | $5,000 | $0 | $5,000 |
| Current bestseller (no change) | 300 | $18 | $5,400 | $40 | $0 |
The retailer records a total write-down by reducing the inventory asset and booking a corresponding expense (often to cost of goods sold, or to a separate loss line for material amounts). The effect: reported profit falls in the current period, taxable income falls with it, and the balance sheet now shows inventory at a value the business can actually realize. The bestseller is untouched — LCNRV only writes down, never up. Notice there is no ongoing schedule here: this is a point-in-time recognition of value that was already lost, not a yearly depreciation charge.
The cash-flow reality behind inventory loss
Here's what write-downs don't show you directly: the cash was already spent. When you wrote the check to your supplier, real money left the business and got parked in stock. A write-down is simply the accounting admission that some of that cash won't come back through sales. That's why inventory problems are, at their core, cash-flow problems.
Two pressures hit at once. First, dead stock ties up working capital you could have used to buy product that actually sells. Second, when slow inventory finally clears — through markdowns or liquidation — it comes back as less cash than went out. The owners who stay liquid are the ones who treat inventory as parked cash with a shelf life: they set reorder points against real sell-through, they discount early rather than letting value bleed to zero, and they keep a clear line of sight between what's on the shelf and what's in the bank. Slow-moving inventory is not just a tax event at year-end; it is a monthly drag on the cash you need to operate and grow.
Decision framework: how to handle at-risk inventory
When a SKU starts aging, work through it in this order rather than defaulting to a year-end write-off:
- Measure the gap. What can you realistically sell it for today, net of selling costs, versus what you paid? If NRV is at or above cost, no write-down — just move it.
- Move it while it still has value. Discount, bundle with fast movers, shift to a secondary channel, or return to the supplier if terms allow. Recovering 60 cents on the dollar in cash beats a clean write-off to zero.
- Write down what won't move. Record the loss in the correct period so your profit and tax reflect reality. Don't carry phantom value.
- Fix the cause. Adjust reorder quantities, tighten the SKUs you carry, or renegotiate supplier minimums so the same dead stock doesn't rebuild.
- Fund the next cycle deliberately. If clearing dead stock left you short for a proven, fast-selling reorder or a seasonal build, decide whether internal cash covers it or whether short-term financing bridges the gap.
That last step is where many owners stall: the good inventory opportunity is in front of them, but the cash is trapped in the slow stock they're still clearing. See our small business financing guide for how working-capital options compare when you need to reorder faster than your cash cycle allows.
Financing inventory when working capital is tight
Depreciation and write-downs are backward-looking — they record value already lost. Financing is forward-looking: it's how you buy the next round of inventory that will actually turn. When a bank line isn't available fast enough, or your credit doesn't clear a traditional lender, revenue-based financing through an MCA marketplace is a common bridge for inventory-heavy businesses.
Unlike a bank, a revenue-based funder underwrites primarily on your bank deposits and revenue rather than your credit score. Typical parameters in this marketplace: funding from around $10,000 and up, FICO 500+ considered, and decisions often in 24 to 48 hours. That speed matters when a seasonal window or a supplier discount is time-sensitive. Repayment flexes as a share of sales, so the cost tracks your cash flow rather than a fixed calendar. It is never guaranteed — approval depends on your deposit history and revenue consistency — and it is best matched to inventory you have real evidence will sell, not to prop up stock that's already aging. Used well, it keeps you buying the fast movers while you clear the slow ones. Our financing guide walks through how to size a request against your turnover so the funding matches the sell-through, not just the shelf.
Frequently asked questions
Can I depreciate inventory like I depreciate equipment?
No. Depreciation applies to fixed assets you use in the business over multiple years, such as vehicles and machinery. Inventory is a current asset you hold to sell, so it stays on the books at cost until it sells or loses value. When its value drops, you record an inventory write-down, not depreciation.
What is the difference between an inventory write-down and a write-off?
A write-down reduces inventory to a lower value it can still be sold for — for example, marking down aging stock that's worth less than you paid. A write-off removes the value entirely because the item can't be sold at all, such as spoiled or destroyed goods. Both reduce the inventory asset and record an expense.
When am I required to write down inventory?
When net realizable value — what you can realistically sell it for minus selling costs — falls below its carrying cost. Common triggers are obsolescence, spoilage or expiration, physical damage, market price declines, and shrinkage from theft or miscounts. The write-down should be recorded in the period the value loss occurs.
Does an inventory write-down reduce my taxes?
It generally reduces taxable income in the period recorded, because the loss increases cost of goods sold or is booked as a separate expense. But rules on timing and documentation matter, and you can't write down inventory just to lower tax. Confirm the treatment with your accountant so it holds up and lands in the right period.
How do I spot slow-moving inventory before it becomes a loss?
Track inventory turnover and run aging reports monthly, grouping stock by how long it has sat. Declining turnover on specific SKUs is the earliest sign value is eroding. Acting on that signal early — discounting, bundling, or moving stock to another channel — usually recovers more cash than waiting for a year-end write-down.
Why is dead inventory a cash-flow problem and not just a tax issue?
Because the cash already left the business when you paid the supplier and got parked in stock. A write-down is just the accounting admission that some of it won't come back through sales. Meanwhile, that money is tied up and unavailable to buy product that actually sells, so slow inventory drags on your operating cash every month.
How can I fund new inventory when my cash is tied up in old stock?
When a bank line isn't fast enough or your credit doesn't clear a traditional lender, revenue-based financing through an MCA marketplace is a common bridge. Funders underwrite on bank deposits and revenue rather than credit score — typically from around $10,000, FICO 500+ considered, with decisions often in 24 to 48 hours. It's never guaranteed and works best for inventory you have real evidence will sell.
Which inventory cost method should a small business use?
It depends on your goods and goals. FIFO tends to raise reported profit in inflation and keeps the balance sheet near current cost; weighted average smooths price swings and suits software-run retail and distribution; specific identification fits high-value, low-volume items. Whatever you pick, apply it consistently and pair it with the lower-of-cost-or-net-realizable-value rule.
