LIFO stands for last in, first out. It means the most recently acquired stock is the first to be used — either in the accounts, where the newest costs are charged against sales, or physically in the warehouse, where the most recently stored items are the first ones taken out.
The term carries both meanings, and they are worth separating from the start. Most of what is written about LIFO concerns accounting, where the method changes reported profit and tax. A smaller but real use concerns storage, where LIFO describes how goods physically flow out of certain racking systems. They are related only by the principle; a business can cost its stock on LIFO whilst rotating it oldest-first on the shelf, and frequently does.
LIFO as an inventory valuation method
When prices change, the cost you record against a sale depends on which purchase you assign it to. LIFO assigns the newest.
The units themselves are irrelevant to this. Nothing physically moves differently. LIFO is a costing convention — an assumption about which cost layer to draw from — applied in the accounts regardless of which cartons actually left the building.
In a period of rising prices, charging the newest and therefore most expensive costs against sales produces a chain of consequences:
- Higher cost of goods sold, because you are using dearer costs.
- Lower reported gross profit as a result.
- Lower taxable income, and therefore lower tax.
- Closing inventory valued at old prices — the oldest, cheapest layers remain on the balance sheet, sometimes for years.
The third of those is the entire commercial case for LIFO, and the fourth is the entire objection to it. You get a tax deferral now in exchange for a balance sheet that progressively stops reflecting what your stock is worth.
In a falling market every one of those reverses, which is worth remembering when LIFO is described as inherently tax-reducing. It reduces tax when prices rise, which happens to be the usual condition.
A worked example under rising costs
You buy the same product three times as prices climb:
| Purchase | Units | Cost each | Total |
|---|---|---|---|
| January | 100 | $8.00 | $800 |
| April | 100 | $10.00 | $1,000 |
| September | 100 | $13.00 | $1,300 |
That is 300 units for $3,100. You sell 220 units at $20 each, so revenue is $4,400.
Under LIFO, take the newest costs first:
- 100 units at the September price: 100 × $13.00 = $1,300
- 100 units at the April price: 100 × $10.00 = $1,000
- 20 units at the January price: 20 × $8.00 = $160
Cost of goods sold = $2,460. Gross profit = $4,400 − $2,460 = $1,940.
Closing inventory is the 80 units left from the January purchase: 80 × $8.00 = $640.
Under FIFO, take the oldest first: $800 + $1,000 + (20 × $13.00) = $2,060. Gross profit = $2,340, closing inventory = 80 × $13.00 = $1,040.
The comparison. Same units sold, same stock on the shelf, and LIFO reports $400 less profit. At a 25% tax rate that is $100 less tax this year — real money, deferred rather than avoided. The cost is a balance sheet carrying stock at $640 when replacing it would cost $1,040, a 38% understatement that widens every year prices rise.
That trade — cash now against an increasingly unrealistic stock value — is the whole of the LIFO decision.
The LIFO reserve and liquidation risk
Two concepts follow from that understated balance sheet, and anyone using LIFO needs both.
The LIFO reserve is the difference between inventory valued under LIFO and what it would be under FIFO. In the example above, $1,040 − $640 = a reserve of $400. US-listed companies using LIFO are required to disclose it, precisely so that readers can restate the accounts onto a comparable basis. Without that disclosure, comparing a LIFO business with a FIFO one is meaningless. The reserve also represents the cumulative tax deferral: it is, roughly, the profit you have not yet reported.
LIFO liquidation is what happens when you sell more than you buy and start eating into those old, cheap cost layers. Because the layers are decades old in some cases, charging them against current sales produces an unusually low cost of goods sold and an artificially high profit — and a tax bill on profit the business never economically earned.
It typically strikes at the worst moment. A business running down stock during a downturn, a supply shortage that prevents replenishment, or a deliberate inventory reduction to free cash will all trigger it. The tax deferred over twenty good years can arrive in a single bad one.
This is a genuine risk rather than a theoretical one, and it is the reason LIFO suits businesses with stable or growing inventory levels and suits businesses with volatile ones badly.
LIFO as a warehouse storage method
The second meaning is physical, and it is where the term belongs to the warehouse rather than the accounts.
A LIFO storage system is one where goods are loaded and retrieved from the same side, so the last pallet in is the first pallet out. The common configurations:
Drive-in racking. Pallets are stored in deep lanes and the forklift drives into the lane to place and retrieve them. Access is from one end only, so the last pallet placed sits at the front and must be removed first. Very high storage density and very poor selectivity.
Push-back racking. Pallets sit on inclined rails or carts. Loading a new pallet pushes the previous one further back; removing one lets the next roll forward. Loading and picking both happen at the front, which makes it LIFO by design.
Block or bulk stacking. Pallets stacked directly on the floor in blocks, accessible only from the outside. The same principle without the steelwork.
When LIFO storage is the right choice. High volumes of a small number of products — the classic case is a few SKUs with many pallets each. Non-perishable goods, or goods with a long enough shelf life that rotation order does not matter. Operations where floor space is expensive and density is worth more than instant access to any given pallet. Cold storage frequently uses it, because chilled and frozen space costs so much per cubic metre that density dominates every other consideration.
When it is the wrong choice. Anything perishable or datable, where stock sitting at the back of a lane for months is a write-off waiting to happen. Broad ranges with few pallets per line, where you would be dedicating a deep lane to two pallets. And anything requiring batch traceability in a strict sequence.
The alternative is a FIFO storage system — selective pallet racking where every pallet is directly accessible, or flow racking loaded at one end and picked from the other. Most warehouses run selective racking as the default and add a LIFO system only for the specific high-volume lines that justify it.
One caution worth stating. Installing LIFO racking does not commit your accounts to LIFO costing, and choosing LIFO costing does not require LIFO racking. They are independent decisions made by different people, and conflating them is a common source of confusion in businesses that do both.
Is LIFO legal?
The answer depends entirely on where you report, and it is the single most consequential fact about the method.
Under US GAAP, LIFO is permitted. American businesses may use it for financial reporting, and many do — particularly in oil and gas, chemicals, metals, automotive parts and grocery distribution, where inventories are large and prices have risen consistently.
Under IFRS, LIFO is prohibited. IAS 2 does not permit it. Since IFRS applies across the European Union, the United Kingdom, Australia, Canada, much of Asia, and more than a hundred jurisdictions in total, LIFO is unavailable to the large majority of businesses worldwide.
The reason for the ban is the balance sheet problem described above. Standard-setters concluded that carrying inventory at costs that may be decades old does not fairly represent its value, and that the method allows profit to be managed through the timing of purchases.
One further US-specific rule matters. The LIFO conformity requirement means a business using LIFO for its US tax return must also use it in its financial statements. You cannot take the tax benefit whilst reporting the higher FIFO profit to investors — which is a deliberate constraint, and it makes the choice a genuine trade-off rather than a free option.
Practically: if you report under IFRS, LIFO is not a decision you get to make. If you report under US GAAP, it is a real choice with a real cost, and it is one to make with an accountant rather than from an article.
Advantages and disadvantages of LIFO
The advantages.
- Lower tax when prices rise. The principal reason anyone chooses it, and for a large inventory in an inflationary period the deferral is substantial.
- Better cash flow, following directly from the lower tax.
- Cost of goods sold reflects current costs. The income statement shows something close to what it costs to replace what you sold, which is arguably a truer measure of the margin actually available.
- It reduces inflationary paper profit. Under FIFO, reported profit in a rising market includes the gap between old purchase costs and today’s replacement cost — money that is not available to spend. LIFO strips that out.
The disadvantages.
- It is banned under IFRS, which rules it out for most of the world.
- The balance sheet becomes unrealistic. Inventory carried at costs from years ago understates what the business holds, sometimes dramatically.
- LIFO liquidation risk. Running stock down triggers tax on profit you did not economically earn, usually at the worst time.
- It is complex to administer. Cost layers have to be tracked and maintained indefinitely, and the LIFO reserve calculated and disclosed.
- Comparability suffers. Your margins cannot be read against a FIFO competitor’s without restating them.
- Lower reported profit may matter for lenders, investors, covenants or a sale process, where the tax saving is not the only consideration.
- It rarely matches physical flow. Few businesses genuinely sell newest-first, so the costing bears no relation to what happened on the shelf.
LIFO vs FIFO, briefly
FIFO charges the oldest costs first; LIFO charges the newest. In a rising market FIFO produces lower cost of goods sold, higher profit, higher tax and stock valued near replacement cost. LIFO produces the reverse on every count.
Neither affects which physical units leave the building, and neither is inherently more accurate — they are conventions, applied consistently.
The decisive practical differences are that FIFO is permitted everywhere and simpler to run, whilst LIFO is permitted only under US GAAP and carries the liquidation risk and the conformity requirement. For a full side-by-side including worked examples in both directions, see FIFO vs LIFO.
Where to go deeper
- FIFO vs LIFO — the full comparison.
- What is FIFO — the method LIFO is measured against.
- Inventory valuation methods — including weighted average and specific identification.
- Selective pallet racking — the FIFO-friendly storage alternative.
- What is FEFO — rotation by expiry date, where dates matter more than order.
- What is deadstock — what LIFO storage produces if you apply it to the wrong goods.
The one-line takeaway
LIFO means last in, first out — charging the newest costs against sales in the accounts, or retrieving the most recently stored pallets first in the warehouse. The accounting version defers tax when prices rise at the cost of an increasingly unrealistic balance sheet, and it is prohibited outside the United States. The storage version buys density at the cost of rotation, and suits only non-perishable goods held in depth.
Frequently asked questions
What does LIFO stand for? Last in, first out. In accounting it means the newest costs are charged against sales first. In warehousing it means the most recently stored goods are the first retrieved, because loading and picking happen from the same side.
How does LIFO work? As a valuation method, each sale is costed against the most recent purchase layer, working backwards through older layers as the newer ones are used up. As a storage method, racking such as drive-in or push-back systems is loaded and unloaded from one face, so the last pallet in is physically the first available.
Is LIFO allowed under IFRS? No. IAS 2 prohibits it, which rules LIFO out across the European Union, the United Kingdom, Australia, Canada and most of Asia. It remains permitted under US GAAP, where it is widely used in industries with large inventories and steadily rising costs.
What is the difference between LIFO and FIFO? FIFO charges the oldest costs against sales, producing higher reported profit, higher tax and stock valued near replacement cost when prices rise. LIFO charges the newest costs, producing lower profit, lower tax and stock carried at old prices. Neither changes which physical units are sold.
What is a LIFO reserve? The difference between inventory valued under LIFO and what it would be under FIFO. US businesses using LIFO must disclose it so their accounts can be compared with those of FIFO businesses. It also represents the cumulative amount of tax deferred.
What is LIFO liquidation? What happens when a business sells more than it buys and starts using up old, cheap cost layers. Charging decades-old costs against current sales produces artificially high profit and a tax bill on earnings the business never economically made — and it usually happens when stock is being run down, which is rarely a good year.
Does LIFO costing require LIFO racking? No. They are independent decisions. A business can cost its inventory on LIFO whilst rotating stock oldest-first on the shelf, and most do, because physical rotation is driven by shelf life rather than by accounting policy.
When should a warehouse use LIFO storage? Where you hold many pallets of a small number of non-perishable products and floor space is expensive. Drive-in, push-back and block stacking all deliver high density in exchange for losing direct access to every pallet. Avoid it for perishables, datable goods, and broad ranges with only a pallet or two per line.
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