When a year-end adjustment relates to an earlier period, the key question is often not the amount but the label: is it a prior period item, a change in accounting estimate, or a change in accounting policy? Under Accounting Standard (AS) 5, those categories have different causes and different presentation or disclosure consequences. Treating every correction connected with an earlier year as a prior period item is a common mistake.
This guide is for entities applying the Accounting Standards framework rather than Ind AS. ICAI’s official AS 5 publication page is the specific first-party reference, and ICAI’s Accounting Standards compendium index as on April 1, 2025 lists AS 5 within the current Accounting Standards collection.
The quickest distinction
- Prior period item: current-period income or expense arising because of an error or omission in preparing financial statements of one or more prior periods.
- Change in accounting estimate: a revised estimate caused by new information, more experience or later developments, without necessarily implying an earlier error.
- Change in accounting policy: a change in the accounting principle or method used to prepare and present financial statements.
The practical test is to ask why the number changed. A prior period item points backward to an error or omission. An estimate change reflects improved information. A policy change alters the accounting basis or method itself.
What is a prior period item under AS 5?
AS 5 defines prior period items as income or expenses that arise in the current period because of errors or omissions in preparing the financial statements of one or more prior periods. The link to an earlier year is not enough by itself; there must have been an error or omission in the earlier financial statements.
Example: a company discovers this year that an electricity invoice received before the previous year-end was accidentally omitted even though the liability should have been recorded then. The correction relates to an earlier-period error. By contrast, if a liability genuinely crystallises only in the current year because the relevant facts or obligation did not exist earlier, it is not a prior period item merely because the commercial matter began earlier.
AS 5 requires the nature and amount of prior period items to be separately disclosed in the statement of profit and loss so their effect on current profit or loss can be perceived.
What is a change in accounting estimate?
Many financial statement numbers depend on estimation. Useful lives, doubtful debts, warranty costs and similar amounts cannot always be known with certainty at the original reporting date. If the original estimate was reasonable using the information then available, a later revision because of better information is a change in estimate, not a prior period error.
The effect of a change in estimate is included in profit or loss in the period of change when it affects only that period, or in the period of change and future periods when both are affected. AS 5 also requires disclosure of the nature and amount of a change in estimate that materially affects the current period or is expected to materially affect later periods. If the amount cannot practicably be quantified, that fact should be disclosed.
Worked example: useful life revised
Assume machinery was originally expected to have a ten-year useful life based on technical information available when purchased. After three years, changed operating conditions lead engineers to conclude that the remaining useful life is four years. If the original estimate was reasonable, revised depreciation is an estimate change affecting the current and future periods; it is not a prior period correction.
What is a change in accounting policy?
An accounting policy is the specific accounting principle and method applied in preparing and presenting financial statements. AS 5 does not permit a policy change simply because management prefers the resulting profit figure.
A change in accounting policy should be made only when a different policy is required by statute, required for compliance with an accounting standard, or when the change is considered to result in a more appropriate presentation of the financial statements.
Where the change has a material effect, it should be disclosed and the material impact and resulting adjustments should be shown in the financial statements of the period in which the change is made. If the effect cannot be ascertained wholly or partly, that fact should be indicated. A change with no material current-period effect but a reasonably expected material effect in later periods should also be disclosed when adopted.
A practical decision framework
- Identify the trigger. Was there an earlier error, new information affecting an estimate, or a change in the accounting principle or method?
- Check what was knowable earlier. If prior-year accounting was reasonable using information then available, the matter is more likely an estimate revision than an error.
- Separate estimate from policy. Revising an asset’s useful life is generally an estimate issue; changing the accounting principle or method is a policy issue.
- Assess materiality and disclosure. Apply the specific AS 5 disclosure requirements to prior period items, material estimate changes and material policy changes.
- Document the evidence. Retain the old estimate or policy, new information, calculations and management rationale.
Three short examples
Missed expense: a supplier invoice that should have been accrued last year was omitted by error. This points to a prior period item.
Estimate revised: management changes the doubtful-debt estimate after new collection information becomes available. If the old estimate was reasonable at the time, this is a change in accounting estimate.
Policy changed: the enterprise changes an accounting method because a statutory or accounting-standard requirement requires it, or because the permitted change results in a more appropriate presentation. This is a policy change.
Common mistakes to avoid
- Calling every expense relating to an earlier year a prior period item.
- Treating new information as proof that the earlier estimate was wrong.
- Using a policy change to achieve a preferred profit outcome without satisfying AS 5.
- Failing to disclose the nature and material effect of estimate or policy changes.
- Failing to preserve evidence supporting the classification.
Practical takeaway
Under AS 5, classify the cause before you classify the accounting. An earlier-period error or omission points to a prior period item; new information or changed circumstances usually point to a change in estimate; and a change in the accounting principle or method is a policy change that must satisfy AS 5’s conditions. A short written memo explaining the trigger, information available at the earlier reporting date and disclosure impact can prevent most year-end misclassification disputes.
