Companies use LIFO — last-in, first-out inventory accounting — mainly to lower their federal income taxes when the prices they pay for inventory are rising. By treating the newest, most expensive units as the ones sold first, LIFO pushes higher costs into the cost of goods sold, shrinks reported profit, and reduces the tax bill. At the flat 21% federal corporate rate, the deferral can be worth real money for any business that carries a large inventory of commodities, raw materials, or manufactured goods.
The Arithmetic Behind the Tax Savings
Inventory valuation feeds directly into cost of goods sold, which is subtracted from revenue to produce gross profit. When input costs are climbing, the most recently purchased inventory is the most expensive. LIFO assigns those recent, higher costs to whatever was sold during the period. Cost of goods sold goes up, gross profit comes down, taxable income comes down with it, and the check to the IRS shrinks.
A distributor buys 1,000 widgets in January at $50 each and another 1,000 in June at $75 each. It sells 1,000 widgets during the year. Under LIFO, cost of goods sold reflects the $75 units and totals $75,000. Under FIFO, it would reflect the $50 units and total $50,000. That $25,000 difference means $25,000 less taxable income under LIFO. At 21%, the company keeps $5,250 in federal tax on that single product line in a single year.
Multiply that pattern across a full inventory over many years of rising prices and the cumulative deferral becomes substantial. Every dollar not paid in tax stays in the business — available for payroll, restocking, equipment, or debt reduction. For inventory-heavy operations, that retained cash is the whole point.
Which Businesses Get the Most Out of LIFO
The method rewards industries with volatile input costs. Oil refiners, steel producers, timber companies, and chemical manufacturers deal with raw materials whose prices can swing significantly within a single quarter. The wider the gap between old costs and current costs, the larger the LIFO deferral. For these businesses, the tax savings justify the accounting complexity the method creates.
Sectors with stable input pricing or fast-turning inventory of low-value goods see much smaller benefits. If prices barely move, LIFO and FIFO produce nearly the same cost of goods sold, and the tax advantage disappears.
Matching Current Costs Against Current Revenue
Beyond tax, LIFO produces an income statement that better reflects what it costs to operate the business today. Accounting theory holds that expenses should be recorded in the same period as the revenue they helped generate. When a company sells a product now, the meaningful cost figure is what it would take to replace that product now, not what similar inventory cost two years ago.
FIFO can create what accountants call phantom profits. A retailer that bought goods cheaply 18 months ago and sells them at today’s higher market price shows a fat margin on paper. Replacing that inventory costs more than it used to, so the real economic profit is smaller than the income statement suggests. LIFO avoids the illusion by pairing current costs against current revenue, giving investors and analysts a more grounded view of operating margins.
The Trade-Offs Companies Weigh Before Choosing LIFO
Lower Reported Earnings and Understated Inventory
The same mechanism that cuts taxes also shrinks reported profit. Companies whose managers are measured on earnings, or whose stock price is sensitive to reported income, absorb a real cost from the optics of lower profit numbers.
The balance sheet takes a hit too. Because LIFO values remaining inventory at the oldest and usually lowest costs, inventory appears cheaper on the books than it actually is at current market prices. That understated figure drags down the current ratio and reduces the collateral value a lender sees when evaluating an asset-based loan. Federal banking examiners specifically flag changes between LIFO and FIFO inventory accounting when monitoring asset-based loans, because the method can mask the true value of collateral backing the credit facility.1Office of the Comptroller of the Currency. Comptrollers Handbook – Asset-Based Lending For capital-intensive businesses that rely heavily on inventory-backed credit lines, that trade-off deserves careful modeling.
The Method Backfires When Prices Fall
LIFO’s tax advantage depends on prices going up. In a deflationary environment where input costs are dropping, the math reverses. The most recently purchased inventory is now the cheapest, so LIFO assigns those lower costs to the goods sold. Cost of goods sold shrinks, reported profit swells, and the tax bill climbs above what FIFO would produce. A company locked into LIFO through a sustained period of falling prices effectively pays more in tax than it would under another method.
LIFO Liquidation Can Trigger a Surprise Tax Hit
The tax benefit accumulates in layers. Each year, the company adds a new cost layer at that year’s prices. The oldest layers at the bottom carry the lowest costs, sometimes dating back decades. As long as the company maintains or grows its inventory, those cheap layers sit undisturbed and never touch the income statement.
Problems start when inventory levels drop. If the company sells more than it purchases in a given year, it eats into those old, low-cost layers. Those costs flow into cost of goods sold, which sounds good until you notice that cost of goods sold is now abnormally low while revenue stays at current prices. Reported income spikes, and taxes spike with it. This is where most companies get burned by LIFO: not in normal operations, but during supply chain disruptions, business contractions, or strategic inventory reductions that were not planned around the tax consequences.
Federal tax law provides narrow relief for involuntary liquidations. Under 26 U.S.C. § 473, if the inventory decline was caused by a qualifying disruption, such as a government regulation affecting energy supplies or a major foreign trade interruption, the company can elect to defer the income impact. It gets up to three years to replace the liquidated inventory, and replacement goods are valued at the original layer costs rather than current prices. The relief only applies to disruptions the Treasury Secretary has formally designated, and the election is irrevocable once made.2Office of the Law Revision Counsel. 26 USC 473 – Qualified Liquidations of LIFO Inventories Ordinary business fluctuations do not qualify.
The Conformity Rule Ties Your Books to Your Tax Return
LIFO is unusual among tax elections: if you use it for taxes, you have to use it for your public financial reports too. Under 26 U.S.C. § 472(c), a company can only claim the LIFO tax benefit if it also uses LIFO when reporting income to shareholders, partners, and creditors. You cannot show low profits to the IRS while showing high profits to investors. If the IRS finds a different inventory method used for financial reporting or credit purposes, it can revoke the LIFO election and force a switch going forward.3Office of the Law Revision Counsel. 26 USC 472 – Last-in, First-out Inventories
Treasury regulations do allow companies to disclose non-LIFO inventory values as supplemental information in footnotes without breaching conformity, which is how public companies satisfy SEC disclosure of the LIFO reserve while keeping the primary statements on LIFO.4eCFR. 26 CFR 1.472-2 – Requirements Incident to Adoption and Use of LIFO Inventory Method
LIFO Is Not Allowed Under IFRS
International Financial Reporting Standards, used by companies in most countries outside the United States, do not permit LIFO. IAS 2 limits inventory cost formulas to specific identification, FIFO, and weighted average cost.5IFRS Foundation. IAS 2 Inventories A U.S. parent using LIFO may need to keep parallel FIFO or weighted average records for foreign subsidiaries that report under IFRS. If the United States ever fully converged with IFRS, companies on LIFO would face a forced switch and recapture of their entire accumulated LIFO reserve in one event.6Securities and Exchange Commission. Commission Statement in Support of Convergence and Global Accounting Standards
Leaving LIFO Is Expensive
The accumulated tax benefit does not disappear when a company changes its mind. When a company drops LIFO, its entire accumulated LIFO reserve, every dollar of income that was deferred over the years, comes back into taxable income through a Section 481(a) adjustment. The additional income is spread over four years: the year of change and the following three.7Internal Revenue Service. Instructions for Form 3115 (12/2022) A company with a $40 million reserve faces roughly $10 million of additional taxable income each year for four years, or about $8.4 million in extra federal tax annually at the 21% rate.
That recapture cost is the single biggest reason companies stay on LIFO even after it stops being optimal. The accumulated reserve functions like an interest-free loan from the government, and repaying it, even spread across four years, can strain cash flow enough to make a switch impractical. The decision to adopt LIFO is closer to a permanent commitment than a year-by-year tax planning move, and the businesses that choose it do so because the ongoing deferral, the cash it preserves, and the honest matching of current costs against current revenue outweigh everything on the other side of the ledger.