How does a change in tax rate affect deferred tax balances under IAS 12?

Under IAS 12, when a change in tax rate is substantively enacted, all deferred tax assets (DTAs) and deferred tax liabilities (DTLs) must be remeasured immediately using the new rate, with the resulting adjustment recognised in the same line (profit or loss, OCI, or equity) as the original deferred tax balance. - Remeasurement trigger — substantive enactment (IAS 12.47): Deferred tax balances must reflect the tax rate expected to apply when the temporary difference reverses. The applicable rate is the one that is enacted or substantively enacted by the reporting date — meaning legislation has passed to the point where its outcome is not in doubt (e.g., Royal Assent in the UK, or presidential signature in the US context for IFRS reporters using local law). - Rate used is the reversal rate (IAS 12.51): Where different rates apply to different levels of taxable income, DTAs and DTLs are measured using the average effective rate expected to apply in the period of reversal — not necessarily the headline statutory rate. This requires judgement about the entity's projected taxable income profile. - Recycling the adjustment through the correct line (IAS 12.58–12.61): The remeasurement gain or loss follows the underlying item. If the original deferred tax arose from a revaluation recognised in OCI, the rate-change adjustment also goes to OCI. If it arose from a transaction in profit or loss, the adjustment hits the income tax expense line — never reclassified to a different statement simply because a rate change prompted it.

If a tax rate change is announced before year-end but the legislation only passes after the reporting date, how should it be treated as a subsequent event under IAS 10 and IAS 12?

- Deferred tax assets — recoverability still required (IAS 12.56): A rate increase raises DTAs in absolute terms, but recoverability must be reassessed simultaneously. If future taxable profits are insufficient, the uplift cannot be recognised. Conversely, a rate decrease reduces the economic value of DTAs, potentially triggering a write-down that compounds existing recoverability concerns. - Disclosure of the rate-change effect (IAS 12.81(d)): Entities must explain the relationship between tax expense and accounting profit (the tax rate reconciliation). A material rate change will appear as a separate reconciling item, showing the quantum of the DTA/DTL remeasurement. This is one of the most scrutinised notes in jurisdictions undergoing rate reform. Scenario: At 31 December 20X4, Entity A holds a DTL of €900,000 arising from accelerated tax depreciation, calculated at the current rate of 30%. On 28 December 20X4, legislation is substantively enacted reducing the corporate tax rate to 25%, effective 1 January 20X5. All temporary differences are expected to reverse after the rate change. - Existing DTL: Temporary difference = €900,000 ÷ 30% = €3,000,000 - Remeasured DTL at 25%: €3,000,000 × 25% = €750,000 - Reduction in DTL: €150,000 → credit to income tax expense (benefit)

Where an entity has both a valuation allowance (unrecognised DTA) and a rate change, in what order should recoverability and remeasurement be assessed under IAS 12.56?

| Account | Dr (€) | Cr (€) | |---|---|---| | Deferred Tax Liability | 150,000 | | | Income Tax Expense (P&L) | | 150,000 | The €150,000 benefit will appear as a separate line in the tax rate reconciliation note, labelled something like "Effect of change in tax rate." If Entity A also had a revaluation surplus-related DTL of €60,000 remeasured down to €50,000, that €10,000 reduction would instead be credited to OCI — not to P&L. - Using the announced rate rather than the substantively enacted rate: Practitioners sometimes apply a rate change the moment a government announces it (e.g., in a budget speech), before the relevant legislation has passed. IAS 12.47 is clear — only substantive enactment qualifies. Premature remeasurement is a prior-period error risk.

How does a phased or stepped tax rate reduction — e.g., 30% in year 1 dropping to 25% in year 3 — affect the measurement of DTLs expected to reverse across multiple periods under IAS 12.51?

- Applying a single rate to all temporary differences: Where graduated tax rates exist or where specific income streams attract different rates (e.g., capital gains vs. trading income), blending all DTAs and DTLs at the headline rate overstates or understates the balance. IAS 12.51 requires the expected average rate for the reversal period. - Misrouting the adjustment in OCI: Teams frequently push the entire rate-change adjustment through tax expense in P&L for simplicity. Auditors will test whether any portion of the remeasured balance relates to items previously recognised in OCI or equity, requiring routing under IAS 12.61. - IAS 12.47 — deferred tax measured at the rate expected to apply when the asset is realised or liability settled; enacted or substantively enacted by reporting date. - IAS 12.51 — use of average effective rate where graduated rates apply to different income levels. - IAS 12.58–12.61 — current and deferred tax recognised outside profit or loss (OCI or equity) when the underlying transaction was recognised outside P&L. - IAS 12.56 — recoverability assessment for deferred tax assets; must be reconsidered at each reporting date including when a rate change affects projected utilisation. - IAS 12.81(d) — mandatory disclosure of the tax rate reconciliation, including the effect of rate changes as a separately identified item.

IAS 12 Effect of Tax Rate Change

IAS 12 Effect of Tax Rate Change — Core Rule

Under IAS 12, when a change in tax rate is substantively enacted, all deferred tax assets (DTAs) and deferred tax liabilities (DTLs) must be remeasured immediately using the new rate, with the resulting adjustment recognised in the same line (profit or loss, OCI, or equity) as the original deferred tax balance.

How IAS 12 Effect of Tax Rate Change Works

Remeasurement trigger — substantive enactment (IAS 12.47): Deferred tax balances must reflect the tax rate expected to apply when the temporary difference reverses. The applicable rate is the one that is enacted or substantively enacted by the reporting date — meaning legislation has passed to the point where its outcome is not in doubt (e.g., Royal Assent in the UK, or presidential signature in the US context for IFRS reporters using local law).

Rate used is the reversal rate (IAS 12.51): Where different rates apply to different levels of taxable income, DTAs and DTLs are measured using the average effective rate expected to apply in the period of reversal — not necessarily the headline statutory rate. This requires judgement about the entity's projected taxable income profile.

Recycling the adjustment through the correct line (IAS 12.58–12.61): The remeasurement gain or loss follows the underlying item. If the original deferred tax arose from a revaluation recognised in OCI, the rate-change adjustment also goes to OCI. If it arose from a transaction in profit or loss, the adjustment hits the income tax expense line — never reclassified to a different statement simply because a rate change prompted it.

Deferred tax assets — recoverability still required (IAS 12.56): A rate increase raises DTAs in absolute terms, but recoverability must be reassessed simultaneously. If future taxable profits are insufficient, the uplift cannot be recognised. Conversely, a rate decrease reduces the economic value of DTAs, potentially triggering a write-down that compounds existing recoverability concerns.

Disclosure of the rate-change effect (IAS 12.81(d)): Entities must explain the relationship between tax expense and accounting profit (the tax rate reconciliation). A material rate change will appear as a separate reconciling item, showing the quantum of the DTA/DTL remeasurement. This is one of the most scrutinised notes in jurisdictions undergoing rate reform.

IAS 12 Effect of Tax Rate Change — Practical Example

Scenario: At 31 December 20X4, Entity A holds a DTL of €900,000 arising from accelerated tax depreciation, calculated at the current rate of 30%. On 28 December 20X4, legislation is substantively enacted reducing the corporate tax rate to 25%, effective 1 January 20X5. All temporary differences are expected to reverse after the rate change.

Remeasurement

Existing DTL: Temporary difference = €900,000 ÷ 30% = €3,000,000
Remeasured DTL at 25%: €3,000,000 × 25% = €750,000
Reduction in DTL: €150,000 → credit to income tax expense (benefit)

Journal entry at 31 December 20X4

Account	Dr (€)	Cr (€)
Deferred Tax Liability	150,000
Income Tax Expense (P&L)		150,000

The €150,000 benefit will appear as a separate line in the tax rate reconciliation note, labelled something like "Effect of change in tax rate."

If Entity A also had a revaluation surplus-related DTL of €60,000 remeasured down to €50,000, that €10,000 reduction would instead be credited to OCI — not to P&L.

IAS 12 Effect of Tax Rate Change — Common Pitfalls

Using the announced rate rather than the substantively enacted rate: Practitioners sometimes apply a rate change the moment a government announces it (e.g., in a budget speech), before the relevant legislation has passed. IAS 12.47 is clear — only substantive enactment qualifies. Premature remeasurement is a prior-period error risk.

Applying a single rate to all temporary differences: Where graduated tax rates exist or where specific income streams attract different rates (e.g., capital gains vs. trading income), blending all DTAs and DTLs at the headline rate overstates or understates the balance. IAS 12.51 requires the expected average rate for the reversal period.

Misrouting the adjustment in OCI: Teams frequently push the entire rate-change adjustment through tax expense in P&L for simplicity. Auditors will test whether any portion of the remeasured balance relates to items previously recognised in OCI or equity, requiring routing under IAS 12.61.

IAS 12 Effect of Tax Rate Change — Key Paragraphs

IAS 12.47 — deferred tax measured at the rate expected to apply when the asset is realised or liability settled; enacted or substantively enacted by reporting date.
IAS 12.51 — use of average effective rate where graduated rates apply to different income levels.
IAS 12.58–12.61 — current and deferred tax recognised outside profit or loss (OCI or equity) when the underlying transaction was recognised outside P&L.
IAS 12.56 — recoverability assessment for deferred tax assets; must be reconsidered at each reporting date including when a rate change affects projected utilisation.
IAS 12.81(d) — mandatory disclosure of the tax rate reconciliation, including the effect of rate changes as a separately identified item.