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When a tax rate changes, remeasure each recognised deferred tax asset and liability at the rate expected to apply when its underlying temporary difference reverses, subject to the applicable accounting standard. A lower future rate reduces both kinds of balance; it normally creates a tax benefit for a net deferred tax liability and a charge for a net deferred tax asset. Then check where the underlying item was recognised before placing the adjustment in profit or loss.
Why a future tax balance changes today
A deferred tax balance is about the tax consequence of recovering an asset or settling a liability in a later period. A taxable temporary difference points to future tax payments and usually a deferred tax liability. A deductible temporary difference points to future deductions and, subject to recognition conditions, a deferred tax asset. The CFA Institute income-tax reading identifies temporary differences, deferred balances and tax disclosures as Level I analysis tasks. The rate applied to a temporary difference therefore matters to the balance sheet before the cash tax is paid.
Imagine a company that has claimed a tax deduction for an asset sooner than it records the related expense in its accounts. Its carrying amount can exceed its tax base. When the company recovers that carrying amount, more taxable income may arise than book income, creating a taxable temporary difference. If the future rate falls, the future tax attached to that existing difference becomes smaller. The tax base and carrying amount do not change merely because the rate changed; the measured tax consequence does.
The reverse intuition applies to an accrued expense recognised in the accounts but deductible for tax only when paid. That can create a deductible temporary difference and a deferred tax asset, provided it meets the relevant recognition test. A rate cut makes a future deduction less valuable in tax terms. The words “rate cut” therefore do not tell you the direction of the accounting effect by themselves. First identify whether the company holds an asset or owes a liability.
Choose the rate and the date carefully
For IFRS reporting, IAS 12 measures deferred taxes using rates expected to apply when the asset is realised or the liability settled, based on tax laws enacted or substantively enacted by the reporting date. The IFRS Foundation’s IAS 12 overview describes the temporary-difference basis and recognition framework. The Foundation’s income-tax implementation module, for the IFRS for SMEs Standard, gives explicit worked guidance on the reporting-date and expected-reversal-rate logic. A political proposal or a prediction of a future law is not itself an enacted or substantively enacted rate.
A law can be passed before a reporting date yet take effect in a later year. If the existing temporary difference is expected to reverse when the new rate applies, the new rate can determine its measurement even though current tax on this year’s profit still uses the old rate. Conversely, if the rate is announced after the reporting date and has not been enacted or substantively enacted at that date, it does not belong in that date’s deferred tax measurement. The financial statements may need disclosure of a material later event, but the subsequent announcement does not rewrite the earlier reporting-date balance.
If different enacted rates apply in different future years, a single headline statutory rate may be misleading. Estimate when each difference reverses and use the relevant rate for that period. If the tax outcome depends on whether an asset is used or sold, the expected manner of recovery matters too. These conditions explain why a compact exam example can use one rate for all differences, while a real issuer’s note may need several schedules and judgments.
An illustrative calculation with both sides
All amounts and rates in this example are invented round numbers, not a current tax law or a real company result. A company has a taxable temporary difference of £600 and a deductible temporary difference of £200. Assume both reverse in a period covered by a rate that was 30% and has become 20% by the reporting date, and assume the deductible difference qualifies for recognition. Both arise from items recognised in profit or loss. Keep the differences fixed while changing only the rate.
| Deferred tax liability on £600 | £180 | £120 | £60 decrease |
| Deferred tax asset on £200 | £60 | £40 | £20 decrease |
| Net deferred tax liability | £120 | £80 | £40 decrease |
The net liability falls from £120 to £80, so this example has a £40 tax benefit in profit or loss. Check it from the gross entries: reducing the liability contributes a £60 benefit, while reducing the asset contributes a £20 charge. The net benefit is £40. This is the result of remeasuring an existing balance, not a claim that the company paid £40 less tax in cash during this reporting period.
Now change only the mix of temporary differences, still as an invented example. If the taxable difference were £200 and the deductible difference £600, the old net position would be a £120 deferred tax asset and the new net position an £80 deferred tax asset. The asset would fall by £40, producing a tax charge for profit-or-loss items. The same rate change can thus have opposite effects across companies. Netting can help explain direction, but calculate gross balances first so an unrecognised asset or different reversal rate is not hidden.
Where the adjustment appears
Do not assume every remeasurement goes through the income statement. Under IFRS, tax related to an item recognised in other comprehensive income or directly in equity generally follows that item. The IFRS Foundation implementation module states the allocation principle and illustrates its effect. In the numerical example above, profit or loss was specified deliberately; it is not a universal destination. An analyst must read the tax note and the originating transaction before attributing a large rate-change effect to ordinary earnings.
A separate illustrative case makes the point. Suppose a £100 taxable temporary difference arises from a revaluation recorded in other comprehensive income, and the relevant rate falls from 30% to 20%. Its deferred tax liability moves from £30 to £20. The £10 reduction follows the location of the underlying revaluation rather than being treated as ordinary operating profit. This example is simplified; actual statements may contain mixed balances that need tracing across several components.
For a loss carryforward, there is another condition. The nominal deduction does not automatically create a full recognised deferred tax asset. Recognition depends on whether sufficient future taxable profit is expected under the applicable rules. A lower rate can reduce the tax value of a recognised carryforward, while changed profit expectations can affect how much is recognised at all. Keep those two drivers separate. Otherwise a candidate may wrongly attribute every movement in a deferred tax asset to the tax-rate change.
What an analyst should take from the tax note
The income-tax note can show a reconciliation from the statutory rate to the effective rate, deferred tax balances by source, unrecognised assets and the effect of changes in laws or rates. Start with the balance-sheet movement, then ask how much of it is a rate remeasurement rather than a new temporary difference, a reversal, a change in recoverability or an acquisition. A lower deferred tax liability does not necessarily mean the issuer’s future cash taxes will fall in the same amount: the payment occurs when the difference reverses, and future profits and rules still matter.
When analysing reported earnings, a rate-change benefit in profit or loss may explain why the effective tax rate looks unusually low for that period. Separating that one-off remeasurement from tax on current-period operations can improve comparison across periods. Yet it would be too blunt to remove the entire tax line: current tax, recurring temporary-difference movements and other permanent differences may remain. The CFA Institute curriculum overview specifically frames the analyst’s task as interpreting disclosures and financial ratios, not just calculating a balance.
For exam practice, write a four-step check: identify taxable and deductible differences; verify recognition and the applicable future rate at the reporting date; recompute assets and liabilities separately; then assign the change to the correct statement component. The CFA programme page situates this topic in Level I study, and the related deferred asset versus liability explanation can help if the starting balance is unclear. The most common mistake is to infer an income-statement gain from the phrase “rate cut” without first checking the net position and origin of the tax item.
Sources
- Analysis of Income Taxes | CFA Institute · cfainstitute.org · Retrieved
- IAS 12 Income Taxes | IFRS Foundation · ifrs.org · Retrieved
- Module 29—Income Tax | IFRS Foundation · ifrs.org · Retrieved
