Strategic Business Reporting (International) · Discussion of issues in financial reporting

IAS 8 Accounting Policies, Estimates and Changes in Regulation

Updated 11 October 2026 · Fact-checked

IAS 8 sets out how to treat changes in accounting policy (retrospective), changes in estimate (prospective) and prior period errors (restate). IFRS 1 covers first-time adoption of IFRS. For new standards, you identify the change, apply the transition rules, then assess the effect on profit, assets, equity and ratios.

Understand Accounting Policies, Estimates and Changes in Regulation

Every set of financial statements rests on accounting policies and estimates. A policy is the specific principle or basis an entity applies, such as the cost model or the revaluation model for property. An estimate is a monetary amount that cannot be measured precisely, such as useful life, an expected credit loss or a warranty provision.

The exam tests whether you can tell these apart. This matters because the treatment differs. A change in accounting policy is applied retrospectively, as if the new policy had always applied. You adjust the opening balance of equity for the earliest period presented and restate comparatives. A change in accounting estimate is applied prospectively. You change the current period and future periods only. Nothing is restated.

An entity may change a policy only in two cases: an IFRS requires it, or the change gives reliable and more relevant information. If a new standard has specific transition rules, those rules override IAS 8. If it has none, you apply IAS 8 retrospectively. Retrospective application can be limited if it is impracticable.

A change in measurement basis, such as cost to fair value, is a change in accounting policy (IAS 8.35). A change in cost formula, such as FIFO to weighted average, is also a change in accounting policy. Only where it is genuinely difficult to distinguish a policy change from an estimate change does IAS 8 say to treat it as an estimate change. Do not use that default as a shortcut for items that are clearly a change of policy.

Prior period errors are omissions or misstatements from failing to use reliable information that was available. You correct material errors retrospectively by restating comparatives. If the error is before the earliest period shown, you restate opening balances of that period. An error is not a change in estimate, so do not hide it as one.

IFRS 1 applies when an entity first prepares IFRS financial statements. It requires you to prepare an opening statement of financial position at the date of transition, using the policies in force at the first reporting date. Adjustments are recognised directly in retained earnings (or, if appropriate, another category of equity). There are mandatory exceptions and optional exemptions, for example deemed cost for property.

For new or amended standards, the exam asks you to explain the effect on the statements and on ratios such as gearing, return on capital and interest cover. Think about which line items move and why. IAS 8 also requires disclosure of standards issued but not yet effective, and of their expected impact.

Key rules to remember

Change in accounting policy: Apply retrospectively: restate comparatives and adjust opening equity of the earliest period presented; Applies unless a standard has specific transition rules or retrospective application is impracticable.
Change in accounting estimate: Apply prospectively: recognise in profit or loss in the period of change and in future periods affected; No restatement of comparatives. Where it changes an asset or liability, adjust its carrying amount.
Prior period error: Restate comparatives retrospectively (material errors); Restate opening balances of the earliest period presented if the error pre-dates it.
Depreciation after estimate change: Revised annual depreciation = (Carrying amount at date of change − Revised residual value) ÷ Remaining useful life; Use the carrying amount at the change date, not original cost.
Policy change test: Change permitted if required by an IFRS, or if it gives reliable and more relevant information; Changing to look better is not a valid reason.
IFRS 1 opening position: Opening IFRS statement of financial position at transition date; adjustments go directly to retained earnings (or, if appropriate, another category of equity); Use IFRS in force at the first IFRS reporting date, subject to exceptions and exemptions.

How to solve Accounting Policies, Estimates and Changes in Regulation questions

Use this method for any question on policies, estimates, errors or new standards.

1Read the requirement and identify what is asked: classify, calculate, or discuss effects.
2Classify each item: policy change, estimate change, error, or first-time adoption. A change in measurement basis, such as cost to fair value, is a policy change, and so is a change in cost formula such as FIFO to weighted average. Treat an item as an estimate by default only where the distinction between policy and estimate is genuinely difficult.
3Check whether a specific standard gives transition rules. If yes, follow them. If no, apply IAS 8.
4Apply the treatment: retrospective with restated comparatives for policy and errors; prospective for estimates.
5Calculate the numbers. For estimates, start from the carrying amount at the change date. For policy changes, work out the adjustment to opening retained earnings and to comparatives.
6Assess the effect on profit, assets, equity and key ratios, and state the direction of each move.
7Add the disclosures and any ethical or judgement point from the scenario, such as earnings management.

Quickest way: Classify, then apply the clock

When to use it: Use this when you have little time and the question asks you to name the treatment.

Ask: is this a basis or a number? A basis is a policy, and that includes a change in measurement basis or cost formula. A number is an estimate.
Policy or error means look back and restate. Estimate means look forward only.
Write the one-line reason, such as 'prospective because a revised useful life is a change in estimate'.
Give the main effect on profit and equity in one sentence, then move on.

Common mistakes in Accounting Policies, Estimates and Changes in Regulation

Restating comparatives for a change in useful life.
Students treat every change as retrospective.
Fix: Useful lives, residual values and provisions are estimates. Apply them prospectively only.
Using original cost when recalculating depreciation after an estimate change.
They forget that the change applies to the remaining carrying amount.
Fix: Take the carrying amount at the date of change, deduct revised residual value, divide by remaining life.
Calling a change in measurement basis or cost formula an estimate.
Both involve numbers changing.
Fix: A change in measurement basis, such as cost to fair value, is a policy change. So is a change in cost formula, such as FIFO to weighted average. Treat an item as an estimate by default only where you genuinely cannot distinguish the two (IAS 8.35).
Applying IAS 8 retrospection when a new standard gives its own transition rules.
Students memorise IAS 8 and ignore the transition paragraphs.
Fix: Check the transition rules in the new standard first. They take priority.
Treating a prior period error as a change in estimate to avoid restating.
It looks less damaging and avoids restatement.
Fix: If information was available and misused or ignored, it is an error. Restate if material.
Discussing ratios without saying which direction they move.
They list items affected but do not link them to ratios.
Fix: State the effect on the numerator and denominator, then the resulting change, for example higher debt raises gearing.

Worked examples

Example 1

An entity bought equipment on 1 January 20X1 for $500,000. It was depreciated straight line over 10 years with no residual value. On 1 January 20X4, management revises the total useful life to 8 years from purchase and estimates a residual value of $20,000. Calculate depreciation for the year ended 31 December 20X4 and state the treatment.

Show the solution

Classify: useful life and residual value are accounting estimates, so the change is prospective.
Annual depreciation before change = 500,000 ÷ 10 = $50,000.
Carrying amount at 1 January 20X4 after 3 years = 500,000 − (3 × 50,000) = $350,000.
Remaining useful life = 8 − 3 = 5 years.
Revised depreciation = (350,000 − 20,000) ÷ 5 = 330,000 ÷ 5 = $66,000.
Do not restate 20X1 to 20X3. Disclose the nature and amount of the change.

Answer: Depreciation for 20X4 is $66,000, charged prospectively with no restatement of prior years.

Example 2

An entity has always valued inventory using FIFO. In the year ended 31 December 20X2 it changes to weighted average cost because this gives more relevant information. 20X1 is the comparative year. Inventory at 1 January 20X1 was $350,000 under FIFO and would have been $338,000 under weighted average. Inventory at 31 December 20X1 was $400,000 under FIFO and would have been $380,000 under weighted average. Ignore tax. Explain the treatment and the adjustments to the 20X1 comparatives.

Show the solution

Classify: the cost formula is an accounting policy, so this is a change in policy.
The change is voluntary but permitted because it gives reliable and more relevant information, and no standard has specific transition rules here.
Apply retrospectively, restating comparatives as if weighted average had always been used.
Cumulative difference at 1 January 20X1 = 350,000 − 338,000 = $12,000.
Cumulative difference at 31 December 20X1 = 400,000 − 380,000 = $20,000. This is the cumulative figure, not the 20X1 profit effect.
Split the adjustment: opening retained earnings at 1 January 20X1 fall by $12,000. The 20X1 profit effect is the movement in the difference = 20,000 − 12,000 = $8,000 reduction (closing inventory is $20,000 lower and opening inventory is $12,000 lower, so cost of sales rises by $8,000).
Check: retained earnings at 31 December 20X1 fall by 12,000 + 8,000 = $20,000. This equals the fall in inventory at that date only because tax is ignored. With tax, retained earnings would fall by less, as a deferred or current tax balance would also change.
The earliest period presented is the year ended 31 December 20X1, so its opening position at 1 January 20X1 is adjusted by $12,000. A third statement of financial position at 1 January 20X1 is required for that earliest comparative period, showing inventory and retained earnings $12,000 lower.
The current year opens at 1 January 20X2, which is the same as the 31 December 20X1 position. Opening inventory and opening retained earnings at 1 January 20X2 are also $20,000 lower than previously reported (12,000 + 8,000), ignoring tax.
Disclose the nature of the change, the reasons, and the adjustment for each line item affected.

Answer: Treat it as a retrospective policy change. Reduce opening retained earnings at 1 January 20X1 by $12,000 and 20X1 profit by $8,000, so inventory and retained earnings at 31 December 20X1, and therefore at 1 January 20X2, are $20,000 lower (ignoring tax). Present a third statement of financial position at 1 January 20X1, the start of the earliest period presented, and give the required disclosures.

Exam tips

Classify first and say why. Markers award marks for the classification and the reasoning.
In calculations, always show the carrying amount at the date of change before applying a new estimate.
When asked about a new standard, structure your answer around effects on profit, assets, liabilities and named ratios.
Link to the scenario. If management gains from a change, comment on whether it is justified and raise earnings management as a professional scepticism point.
For IFRS 1 questions, mention the transition date, the opening statement of financial position and that adjustments go directly to retained earnings (or, if appropriate, another category of equity).

Practice questions from Discussion of issues in financial reporting

Accounting Policies, Estimates and Changes in Regulation in other exams

The same ground in other exams, if you are preparing for more than one or want another angle on it.

Accounting Policies, Estimates and Changes in Regulation: frequently asked questions

What is the difference between a change in accounting policy and a change in estimate?

A policy is the principle or basis used, such as FIFO or the revaluation model. An estimate is a judgement about an uncertain amount, such as useful life. Policy changes are retrospective. Estimate changes are prospective. A change in measurement basis, such as cost to fair value, is a policy change. Only where the two are genuinely hard to tell apart is the change treated as an estimate.

Is a correction of an error the same as a change in estimate?

No. An error arises from misusing or ignoring reliable information that was available. You restate comparatives for a material error. An estimate change reflects new information and is applied going forward.

What does IFRS 1 require on first-time adoption?

The entity prepares an opening IFRS statement of financial position at the transition date using the IFRS in force at its first reporting date. Adjustments are recognised directly in retained earnings or, if appropriate, another category of equity. There are mandatory exceptions and optional exemptions.

How do I assess the impact of a new standard on the financial statements?

Identify what changes in recognition or measurement, then trace the effect on profit, assets, liabilities and equity. Finish with the effect on ratios, such as gearing or return on capital, and note the disclosures.