Written byUseful life is the period an asset is expected to be available for use by a business, and the number of years over which its cost is depreciated.
Also known as: asset life, remaining useful life, depreciable life
Key points
- It is a management estimate based on expected usage, wear, obsolescence, maintenance plans and any legal or contractual limits.
- For tax the ATO uses its own term, effective life, published in tables you can adopt or depart from with evidence.
- A longer life means smaller annual depreciation and higher reported profit; a shorter life does the opposite.
- Remaining useful life is what is left of that period at a given reporting date.
- Under AASB 16 a lessee amortises a right-of-use asset over the shorter of the lease term and the asset's useful life, unless ownership transfers.
How useful life works
When you buy a ute, excavator or server, you estimate how long it will be available for use: a number of years, operating hours or units of output, whichever best reflects how it wears. That estimate sets the period over which you spread the cost as depreciation, so it feeds directly into your profit and loss, the carrying amounts on your balance sheet and your cash flow planning. It applies to intangible assets such as software and licences as well as physical ones.
Useful life is an estimate, and it needs evidence: manufacturer specifications and warranty periods, industry benchmarks, your own maintenance and usage history, spare-part availability, the risk of technological obsolescence, and any regulatory or contractual limits. Keep the supplier quotes, service logs and worksheets behind the number, because auditors and the ATO may ask for them.
Useful life vs effective life for tax
Accounting and tax can use different lives for the same asset. For your financial statements, useful life is your management estimate under the AASB standards. For your tax return, the ATO refers to an asset's effective life: it publishes tables of effective lives that you can adopt, or you can self-assess a different life if you can justify it with evidence.
The two often diverge. If the ATO's effective life is shorter than your accounting estimate, the tax deductions arrive faster than the accounting expense, reducing taxable income earlier while the accounts show the longer pattern of use. Track the two separately in your asset register or depreciation schedule, and apply the same approach across similar assets so the estimates hold up to scrutiny.
When to reassess useful life
Revisit the estimate when something changes: a big shift in usage or shift patterns, unexpected damage or deterioration, a technological or regulatory change, a major refurbishment that extends the asset's life, or evidence that the original estimate was unreasonable. In your accounts a revised useful life is a change in estimate, applied prospectively to future depreciation and disclosed if material. For tax, check how the ATO's effective life rules apply and how earlier claims were made.
Useful life matters when you finance an asset, too. Matching the loan or lease term to the asset's useful life keeps the repayments in step with the years the asset is actually working for you. Under AASB 16, if the lease transfers ownership or a purchase option is reasonably certain to be exercised, the right-of-use asset is amortised over the useful life rather than the lease term.
Example
A business buys a $20,000 machine with an expected salvage value of $2,000. Management estimates it will be in use for seven years, so the accounts show straight-line depreciation of about $2,571 a year. The ATO's effective life for the same machine is five years, so for tax the cost is deducted over five years rather than seven. The tax deductions run ahead of the accounting expense in the early years, reducing taxable income sooner, while the accounts reflect the longer period the business expects to use the machine.
Not to be confused with
- Economic life
- economic life is how long an asset is worth operating, which can be shorter than the period it is physically usable
- Lease term
- the lease term is how long the lease contract runs, which can be shorter than the asset's useful life
Frequently asked questions
What is the difference between useful life and effective life?
Useful life is your own estimate under the accounting standards of how long the asset will be available for use, and it drives the depreciation in your financial statements. Effective life is the ATO's term for tax depreciation: it publishes tables you can adopt, or you can self-assess with evidence. The two can differ for the same asset.
How do you estimate the useful life of an asset?
Gather evidence: manufacturer specifications and warranty periods, industry benchmarks, your own usage and maintenance records, spare-part availability and any regulatory or contractual limits. Consider how hard the asset will be worked, the risk of obsolescence and your maintenance plans, then document the reasoning so it stands up to an auditor or the ATO.
Can the useful life of an asset be changed?
Yes. If there is new evidence or circumstances change, such as heavier use, damage, a technology shift or a major refurbishment, you revise the estimate. In the accounts this is a change in estimate applied prospectively, with material effects disclosed. For tax, check how the ATO's effective life rules and your earlier claims are affected.
What is the typical useful life of a vehicle or computer?
There is no single answer, and the published figures change over time. Light vehicles and general plant are usually given the longest lives, and IT equipment such as laptops and servers the shortest. Use the ATO's effective life tables for the tax figure that applies to your asset, and your own usage and maintenance evidence for the accounting estimate.
How does useful life affect a lease?
Under AASB 16 a lessee amortises the right-of-use asset over the shorter of the lease term and the asset's useful life, unless the lease transfers ownership or a purchase option is reasonably certain to be exercised, in which case the useful life applies. Where the lease is an operating lease, the lessor keeps the asset on its books and depreciates it over the asset's own useful life.
Related terms
Depreciation
Depreciation is the fall in an asset's value over time, spread across the years the asset is used so the cost can be claimed as a tax deduction.
Read definitionEconomic life
Economic life is the period during which an asset keeps earning enough to justify running it, after allowing for maintenance costs, lost efficiency, new technology and market demand.
Read definitionSalvage value
Salvage value is the informal name for what AASB 116 calls an asset's residual value: what it will fetch at the end of its useful life.
Read definitionStraight-line depreciation
Straight-line depreciation is a method that spreads an asset's cost, less its expected salvage value, evenly over its useful life so the same amount is deducted each year.
Read definitionWritten-down value (WDV)
Written-down value (WDV) is a depreciating asset's cost less the depreciation claimed so far, and the base for future deductions and for gains or losses on disposal.
Read definitionAsset register
An asset register is a structured record of the tangible and intangible assets a business owns, controls or leases, tracking each item's location, value, depreciation and disposal in one place.
Read definitionGo deeper
Sources
This article is general information only and is not financial advice.