An obsolete inventory write-off runs on two separate tracks. On your books, GAAP requires you to recognize the loss as soon as you identify stock whose value has fallen below cost. For your tax return, the IRS generally won’t let you deduct that loss until you physically dispose of the goods, sell them below cost in a genuine offering, or destroy them with documentation. Handling only one track leaves either your balance sheet overstated or a legitimate deduction on the table.
What Counts as Obsolete
Obsolete inventory is stock you’re unlikely to sell or use in production at normal prices. The goods can be physically intact and still qualify, because obsolescence is an economic condition: technology moved on, demand expired, the item deteriorated, or you simply bought more than the market would absorb.
Three tools together produce the evidence you’ll need for both the write-down and the eventual deduction. An inventory aging report flags items that have sat beyond a threshold you set. A sales forecast comparison shows where stock on hand outruns any reasonable projection of demand. Physical inspection by warehouse staff confirms whether the flagged goods are damaged, expired, or otherwise unmarketable. Data alone can miss condition problems; a walk-through alone can miss slow-movers hiding in a well-kept aisle.
The GAAP Write-Down
Inventory measured under FIFO, average cost, or any method other than LIFO or the retail method must be carried at the lower of cost and net realizable value.1Financial Accounting Standards Board. ASU 2015-11 Inventory (Topic 330) When evidence shows an item’s NRV has dropped below its recorded cost, you recognize the difference as a loss in the period you find it. You do not wait for the goods to leave the building.
Net realizable value is the estimated selling price in the ordinary course of business, minus reasonably predictable costs of completion, disposal, and transportation.1Financial Accounting Standards Board. ASU 2015-11 Inventory (Topic 330) For truly obsolete goods, NRV is often zero or close to it, so the entire carrying cost becomes the loss.
Recording the Entry
Most companies debit Cost of Goods Sold, or a separate account such as Loss on Inventory Obsolescence, and credit an Allowance for Inventory Obsolescence. Using an allowance account rather than writing the inventory balance down directly preserves the original cost in the general ledger while the balance sheet shows the reduced net figure. Inventory that originally cost $100,000 with a $40,000 allowance appears as $60,000 net. Auditors can still trace the full cost, and readers of your statements see the realistic value.
The income statement hit is immediate. The debit reduces gross profit or operating income in the current period, and a large single-quarter write-down can visibly shift gross margin and current ratio.
Calculate each write-down against specific items or identifiable categories rather than applying a blanket percentage across all stock. Specific identification is what the LCNRV rule expects and what auditors want to see. If conditions later improve, GAAP does not allow you to write the item back up above its original cost.
Closing Out the Reserve
The write-down creates a reserve, not a disposal. When the goods eventually leave, you clear both sides. Scrapped with no recovery: debit the Allowance for Inventory Obsolescence and credit Inventory for the full original cost. Sold for a nominal amount: debit Cash for the recovery, debit the Allowance for the written-down portion, and credit Inventory for the original cost. The loss itself was already recognized when you set up the reserve.
The Tax Deduction Is a Separate Question
The write-down you just recorded does not automatically produce a tax deduction. The IRS generally will not let you deduct a loss based solely on a book reserve or allowance. You need something more concrete: an actual offering at reduced prices, a sale below cost, or physical destruction.
The 30-Day Offering Rule
Treasury Regulation 1.471-2(c) permits you to value unsalable or unusable goods at their bona fide selling price minus direct disposal costs, but only if that selling price reflects an actual offering of the goods during a period ending no later than 30 days after the inventory date.2eCFR. 26 CFR 1.471-2 – Valuation of Inventories The regulation covers goods that are damaged, imperfect, shop-worn, out of style, or in odd or broken lots. Marking items down on paper does not satisfy it. You have to try to sell them.
The burden of proof is yours. Keep records showing the goods actually fit those classifications, how they were offered, and how they were ultimately disposed of.2eCFR. 26 CFR 1.471-2 – Valuation of Inventories
Deducting the Full Cost
To deduct the full cost of worthless inventory, you generally need to show the goods were physically destroyed, scrapped, or sold below cost. Destruction produces the cleanest evidence: physical count sheets, a record of the destruction method and date, the specific items involved, and ideally a third-party destruction certificate. For goods sold at deep discount, keep the sales invoices and evidence of the promotional effort behind the offering.
The Timing Gap
Because GAAP wants the loss when you identify it and the IRS waits for disposition, a temporary difference opens up between book and tax. The inventory’s carrying value on your balance sheet (after the write-down) sits below its tax basis (still at full cost). Under ASC 740, that deductible temporary difference creates a deferred tax asset representing the future benefit you’ll capture when you dispose of the stock and claim the deduction. If realizing that benefit looks doubtful, a valuation allowance may be required against it.
Choosing a Disposition Method
Once the books are written down, the physical stock still has to go somewhere. Your choice affects cash recovery, the documentation you produce for the IRS, and whether you inherit any regulatory obligations.
Liquidation Sales
Selling through liquidation channels or secondary markets recovers some cash and generates clean sales invoices for the tax record. Under Treas. Reg. 1.471-2(c) the reduced price has to be genuine and the offering legitimate; a token sale to a related party will not hold up.2eCFR. 26 CFR 1.471-2 – Valuation of Inventories
Scrapping and Destruction
When the goods have no resale value or carry liability risk, destruction is the appropriate route. Record the date, the method, and the specific items destroyed. A third-party witness or compliance officer’s verification strengthens the file. Complete documentation supports a deduction for the full cost basis of what was destroyed.
Charitable Donation
Donating obsolete inventory to a qualified charity can produce a larger tax benefit than a plain cost-basis deduction, particularly for C corporations. Under IRC Section 170(e)(3), a C corporation donating inventory to a qualifying organization can claim an enhanced deduction equal to the item’s cost basis plus half the difference between cost basis and fair market value, capped at twice the basis.3Office of the Law Revision Counsel. 26 USC 170 – Charitable, Etc., Contributions and Gifts
The conditions are strict. The charity must use the property for the care of the ill, the needy, or infants. The charity cannot resell the goods and must provide a written statement confirming how it will use and dispose of them. Items regulated under the Federal Food, Drug, and Cosmetic Act must fully comply with that law on the donation date and for the 180 days prior.3Office of the Law Revision Counsel. 26 USC 170 – Charitable, Etc., Contributions and Gifts
Food donations have a broader rule. Any business, not just a C corporation, can claim the enhanced deduction for apparently wholesome food donated from a trade or business. Non-C-corporation taxpayers face a cap of 15% of aggregate net income from the trades or businesses making the contributions.3Office of the Law Revision Counsel. 26 USC 170 – Charitable, Etc., Contributions and Gifts
Environmental Rules That Constrain Disposal
Destroying inventory is not always a matter of moving it to a dumpster. If the goods qualify as hazardous waste under the Resource Conservation and Recovery Act, on-site accumulation limits apply: large quantity generators can hold hazardous waste for no more than 90 days without a permit, and small quantity generators can hold it for up to 180 days, or 270 days if the waste has to be transported 200 miles or more for disposal.4eCFR. 40 CFR Part 262 – Standards Applicable to Generators of Hazardous Waste Exceeding the limits pulls your facility into the full permitting regime for treatment, storage, and disposal.
Hazardous waste manifests, test results, and waste analysis records must be kept for at least three years from the date the waste was last sent to treatment, storage, or disposal.4eCFR. 40 CFR Part 262 – Standards Applicable to Generators of Hazardous Waste Those files also serve as the disposition documentation the IRS expects.
Electronic inventory needs its own check. Most consumer electronics are not classified as hazardous waste under RCRA, but items containing lead solder, mercury switches, or certain batteries can trigger hazardous waste requirements when they exhibit characteristics like toxicity. Waste cathode ray tubes and many removed batteries are subject to specific federal export and reporting rules.5U.S. Environmental Protection Agency. New International Requirements for Electrical and Electronic Waste Test before choosing a disposal path; when the answer is unclear, treat the material as hazardous until testing shows otherwise.
Keep destruction certificates, liquidation invoices, charitable acknowledgment letters, and any third-party verification for as long as the tax year stays open for audit. That is generally three years from the filing date, extending to six years if gross income is understated by more than 25%. Setting environmental and tax retention to the longer period avoids gaps that could sink a deduction.
Small Business Exemption and Method Changes
Businesses that meet the gross receipts test under Section 448(c), generally those with average annual gross receipts of $30 million or less over the prior three years, can elect to treat inventory as non-incidental materials and supplies or conform to their financial statement method.6Office of the Law Revision Counsel. 26 USC 471 – General Rule for Inventories The simpler approach can narrow the book-tax timing gap for smaller operations.
Any change in how you value inventory, including adopting the small business exemption or correcting a method you’ve been misapplying, requires Form 3115, Application for Change in Accounting Method. Many inventory changes qualify for automatic consent: you attach the original Form 3115 to your timely filed return for the year of change and send a signed copy to the IRS National Office.7Internal Revenue Service. Instructions for Form 3115 The change takes effect at the beginning of that tax year, and a Section 481(a) adjustment prevents income from being duplicated or omitted in the transition. Non-automatic changes must be filed during the tax year you want them to apply, so check the current revenue procedure before assuming which category yours falls into.