Spare parts under ASC 360 and IAS 16: when they are PP&E or inventory

Spare parts belong in property, plant and equipment when the entity expects to use them for more than one period and they serve specific long-lived assets; small parts consumed in routine maintenance belong in inventory and reach the income statement when they are used. IAS 16 Property, Plant and Equipment states this rule in a single paragraph. US GAAP reaches a similar answer through the definitions in ASC 360 and ASC 330 and the definition of current assets, without a dedicated spare-parts paragraph, which leaves more room for entity policy.

The classification decides far more than a balance sheet caption. A part carried as PP&E is depreciated, tested for impairment as part of an asset or asset group, and bought with cash that appears in investing activities. A part carried as inventory is not depreciated, is written down to net realizable value when it loses value, sits in current assets and working capital, and is bought with operating cash. A manufacturer, utility, airline, mine or data-center operator holding millions of dollars of critical spares can see the choice move EBITDA, working capital ratios, capital expenditure figures and debt covenant calculations at the same time.

The question usually surfaces at three moments: when a large spare is bought together with new equipment, when a maintenance department builds a stock of repairable components, and when auditors ask why a warehouse balance labeled inventory contains items that have sat on shelves for several years waiting for a breakdown that may never come.

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IAS 16 PARAGRAPH 8: SPARE PARTS, STAND-BY AND SERVICING EQUIPMENT.

IAS 16 defines property, plant and equipment in paragraph 6 as tangible items held for use in the production or supply of goods or services, for rental to others or for administrative purposes, and expected to be used during more than one period. Paragraph 7 adds the general recognition test: an item is recognized as an asset when it is probable that future economic benefits will flow to the entity and its cost can be measured reliably.

Paragraph 8 applies those definitions directly to spare parts, stand-by equipment and servicing equipment. Such items are recognized as property, plant and equipment when they meet the definition of property, plant and equipment; otherwise they are classified as inventory under IAS 2 Inventories. The wording of paragraph 8 was amended by the Annual Improvements to IFRSs 2009-2011 Cycle, as paragraph 81G of the standard records, clarifying that servicing equipment follows the same definitional test as spare parts and stand-by equipment.

The IFRS test therefore turns on two facts. The first is the expected period of use: a part expected to be used during more than one period meets that element of the definition, while a part consumed within the year does not. The second is the purpose for which the item is held: a part held to keep the entity's own equipment running is held for use, while parts held for sale to customers, or materials consumed in rendering services, fall under the IAS 2 definition of inventories.

Paragraph 9 gives entities latitude on the unit of measure. IAS 16 does not prescribe what constitutes an item, and it notes that it may be appropriate to aggregate individually insignificant items such as moulds, tools and dies and apply the criteria to the aggregate value. In practice, this paragraph supports capitalization thresholds and pooling of small, similar parts.

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SPARE PARTS UNDER ASC 360 AND ASC 330.

The FASB Codification contains no general paragraph equivalent to IAS 16 paragraph 8. Classification under US GAAP follows the definitions instead. The ASC 330 glossary defines inventory as tangible personal property held for sale in the ordinary course of business, in process of production for such sale, or to be currently consumed in the production of goods or services to be available for sale. ASC 360 covers long-lived tangible assets held and used in operations. The definition of current assets in ASC 210 covers resources reasonably expected to be realized in cash, sold or consumed during the normal operating cycle of the business.

Read together, these definitions produce a practical line close to the IFRS one. Low-value parts and supplies consumed in normal operations, such as filters, belts, lubricants and fasteners, are inventory or supplies and are expensed when used. Major spares, stand-by units and repairable components that the entity expects to hold and use beyond the operating cycle are usually classified as noncurrent assets and capitalized as PP&E, then depreciated.

Because US GAAP leaves the line to definitions and policy, entities document a capitalization policy covering thresholds, the treatment of repairable parts and the point at which depreciation starts, and apply it consistently. Industry practices also shape the result, particularly in airlines and utilities, where large pools of repairable parts are common. Two entities with similar spares can therefore present them differently under US GAAP if each applies a reasonable, consistent and disclosed policy.

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ASC 360 VS IAS 16: SPARE PARTS CLASSIFICATION COMPARED.

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Point	IAS 16 / IAS 2	ASC 360 / ASC 330
Explicit rule	Yes, IAS 16 paragraph 8	No dedicated paragraph
Main test	PP&E definition, use over more than one period	Inventory and current asset definitions
Small parts	Inventory, expensed when used	Inventory or supplies, expensed when used
Unit of measure	Not prescribed, aggregation allowed	Entity capitalization policy
Component depreciation	Required for significant parts	Permitted, not required
Replaced part	Carrying amount derecognized	Retired when cost is identifiable
Impairment if PP&E	IAS 36, reversal allowed	ASC 360, no reversal
Write-down if inventory	Net realizable value, reversal allowed	Lower of cost and NRV, no reversal

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The comparison shows that the classification outcome for a given part is usually the same under both frameworks, while the mechanics around it differ. The larger differences sit in the component approach, covered in detail in how component depreciation works under IAS 16 and ASC 360, and in impairment and write-down reversals.

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WHEN DEPRECIATION OF CAPITAL SPARES BEGINS.

IAS 16 paragraph 55 states that depreciation begins when an asset is available for use, meaning in the location and condition necessary for it to be capable of operating in the manner intended by management. For a stand-by generator installed and ready to switch on, that point is reached on installation. For a spare motor kept in a warehouse, ready to be fitted when the operating unit fails, entities apply judgement: many treat the spare as available for use from acquisition because its purpose is to stand ready, while others start depreciation on installation when the spare cannot deteriorate or lose value while stored.

Under US GAAP, depreciation follows the general ASC 360 principle of allocating cost over the period in which the asset provides service, and the same judgement arises. A common approach links the depreciation period of a dedicated spare to the remaining life of the asset it supports, because the spare loses its usefulness when that asset is retired. Whatever the method, the policy needs to be written down, applied consistently and supported by evidence of how the parts are actually used.

Depreciation of a capital spare that is idle does not stop because the spare has not yet been fitted. Both frameworks treat depreciation as a systematic allocation of cost, and an asset held ready for use still consumes part of its useful life through obsolescence and the approaching retirement of the equipment it serves.

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WORKED EXAMPLE: SPARE PARTS CLASSIFICATION WITH JOURNAL ENTRIES.

The figures below are illustrative. On January 1, 2026, a US manufacturer that reports under US GAAP, with a subsidiary reporting under IFRS, buys three groups of parts for a production line with 10 years of remaining useful life. The entity's year end is December 31, and all amounts are in USD.

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Item	Cost (USD)	Expected use	Classification
Stand-by drive motor for the line	240,000	Held until the main motor fails	PP&E
Pool of 6 repairable pumps at 15,000	90,000	Swapped, repaired, reused for 5 years	PP&E
Bearings, belts and filters	36,000	Consumed within the year	Inventory
Total	366,000

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The stand-by motor is dedicated to one line and is expected to serve until the line is retired, so it is depreciated straight line over the line's 10 remaining years with no residual value, giving USD 24,000 per year. The repairable pumps rotate between service and repair, are expected to last 5 years and are depreciated as a pool, giving USD 18,000 per year. During 2026, USD 27,500 of bearings, belts and filters are used in routine maintenance.

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Date	Account	Debit (USD)	Credit (USD)
Jan 1, 2026	PP&E, stand-by equipment	240,000
Jan 1, 2026	PP&E, repairable pumps	90,000
Jan 1, 2026	Inventory, maintenance supplies	36,000
Jan 1, 2026	Cash or accounts payable		366,000
During 2026	Repairs and maintenance expense	27,500
During 2026	Inventory, maintenance supplies		27,500
Dec 31, 2026	Depreciation expense	42,000
Dec 31, 2026	Accumulated depreciation, stand-by		24,000
Dec 31, 2026	Accumulated depreciation, pumps		18,000

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At December 31, 2026, the balance sheet shows capital spares with a net book value of USD 288,000 (USD 216,000 for the motor and USD 72,000 for the pumps) and maintenance supplies inventory of USD 8,500. The cash flow statement shows USD 330,000 of capital expenditure in investing activities, while the USD 36,000 of supplies is an operating outflow.

On July 1, 2027, the main drive motor fails. Its carrying amount as a separately depreciated component is USD 50,000 (cost USD 200,000, accumulated depreciation USD 150,000 after depreciation to the date of failure), and it is sold for scrap for USD 5,000. The stand-by motor is fitted and stays in PP&E with a carrying amount of USD 204,000 (cost USD 240,000 less accumulated depreciation of USD 36,000), continuing at USD 24,000 per year because its depreciation was already tied to the life of the line.

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Date	Account	Debit (USD)	Credit (USD)
Jul 1, 2027	Cash, scrap proceeds	5,000
Jul 1, 2027	Accumulated depreciation, old motor	150,000
Jul 1, 2027	Loss on derecognition of PP&E	45,000
Jul 1, 2027	PP&E, old motor		200,000

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Under IFRS, IAS 16 paragraph 70 requires the carrying amount of the replaced part to be derecognized whether or not it was depreciated separately, and paragraph 68 states that gains on derecognition are not classified as revenue. Under US GAAP, the same entry applies when the old motor's cost is identifiable in the fixed asset register, which is why a register that tracks major components separately simplifies replacement accounting under both frameworks. The repair cost of a pump returned from the workshop is a maintenance expense in both cases, unless the work extends the pump's life or capacity under the entity's policy.

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Dec 31, 2026 (USD)	Classified as above	All parts as inventory
PP&E, capital spares (net)	288,000	0
Inventory	8,500	338,500
Depreciation expense 2026	42,000	0
Capital expenditure in investing	330,000	0

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If every part had been booked as inventory, 2026 pre-tax profit would be higher by USD 42,000 of missing depreciation, current assets would be overstated by USD 330,000, and reported capital expenditure would be understated by the same amount. Ratios that use working capital, EBITDA or capex would all move, which is why lenders and auditors look closely at large spare-parts balances. The inventory side of the same balance sheet is discussed further in how inventory is measured and reported under IAS 2 and ASC 330.

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PRESENTATION AND DISCLOSURE OF CAPITAL SPARES.

Capital spares are presented within property, plant and equipment, often as a separate class or within machinery and equipment, and they enter the reconciliation of carrying amounts that IAS 16 requires for each class. Entities with material balances commonly describe in their accounting policy which parts are capitalized, how they are depreciated and when depreciation starts. Under US GAAP, the property note and the accounting policy disclosure play the same role, and SEC registrants with significant spares often describe their policy for repairable and expendable parts.

Spare parts classified as inventory are included in the inventory note, usually within materials and supplies. Under IAS 2, the entity discloses write-downs and reversals of write-downs. Under ASC 330, a write-down to the lower of cost and net realizable value, for inventory measured under methods other than LIFO and the retail inventory method, creates a new cost basis that is not written back up in later annual periods.

In the cash flow statement, purchases of capital spares are capital expenditures in investing activities under both IAS 7 and ASC 230, while purchases of maintenance supplies are part of operating cash flows. A reclassification of spares from inventory to PP&E is a non-cash transfer and does not create an investing outflow at the date of the transfer.

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COMMON ERRORS IN SPARE PARTS ACCOUNTING.

The most frequent error is booking every spare as inventory because the parts sit in the same warehouse as consumables. The physical location of a part does not decide its classification; its expected period of use and its purpose do. A periodic count often reveals the problem when slow-moving critical spares appear on aging reports year after year, a pattern covered in physical inventory count under ASC 330: shrinkage and cut-off entries.

A second error is capitalizing spares and then forgetting to depreciate them until installation, without a documented policy that supports a delayed start. A third is keeping capital spares on the books after the equipment they serve has been retired or sold; once the related asset is gone, the spare's recoverable amount under IAS 36, or its recoverability under ASC 360, needs to be reassessed, and an impairment or disposal entry usually follows.

Judgement areas include the capitalization threshold, the depreciation period for dedicated spares, the grouping of repairable parts into pools, and the treatment of parts bought with new equipment as part of the initial purchase. Spare parts bought together with a machine at a single price are allocated a share of the purchase price, and that share is then classified under the same tests as a spare bought separately. Tracking these items in a fixed asset schedule, such as the one built in this capex and depreciation schedule in Excel, keeps the depreciation start dates and replacement entries auditable.

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SPARE PARTS CLASSIFICATION CHECKLIST.

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Step	Question to answer
1	Is the part held for the entity's own equipment or for sale?
2	Will it be used over more than one period or operating cycle?
3	Is its cost above the capitalization threshold, alone or pooled?
4	Is it dedicated to one asset, and what is that asset's remaining life?
5	When does depreciation start under the written policy?
6	Is the replaced part's carrying amount identifiable for derecognition?
7	Are spares for retired equipment reviewed for impairment or disposal?

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SPARE PARTS AS PP&E OR INVENTORY: CONCLUSIONS UNDER ASC 360 AND IAS 16.

IAS 16 gives an explicit answer: spare parts, stand-by equipment and servicing equipment are PP&E when they meet the definition of property, plant and equipment, and inventory otherwise. US GAAP has no equivalent paragraph, but the definitions of inventory, current assets and long-lived assets lead most entities to the same split, with major and repairable spares capitalized and routine consumables expensed as used.

The areas left to judgement are the capitalization threshold, the start of depreciation for spares held in storage, the depreciation period for dedicated spares and the pooling of repairable parts. Under US GAAP those choices rest on a written policy applied consistently, and under IFRS they rest on the PP&E definition, the unit-of-measure latitude in paragraph 9 and the component requirements of paragraphs 43 to 47. In both frameworks, a misclassification changes profit, working capital and reported capital expenditure together, so the policy and the fixed asset register deserve the same attention as the warehouse count.

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