Last year's figure changed: rebuild the comparison before explaining growth

A current financial statement package shows a prior-year amount different from the one in last year's report. Before describing the business's growth, establish why the comparative changed. A correction, a policy change or another presentation adjustment can alter the starting point even though the underlying period has already ended.

Read the current note explaining the change and identify the applicable reporting framework. Under IAS 8, the IFRS Foundation distinguishes retrospective correction of material prior-period errors, subject to the standard's conditions, from changes in estimates arising from new information, which are recognized prospectively. A reader should not treat every changed comparative as the same event.

This guide focuses on using revised information in analysis. It does not determine whether a particular correction, restatement or filing process is required. Have the responsible accountant explain that conclusion for the actual facts. Your first task is to understand which published version and basis should support the comparison you are making.

Keep the originally issued statements and the current package available. Identify the statement line, period, units and reporting entity for each figure. A change in the company perimeter or a switch from parent-only to consolidated information can create a different comparison problem from a correction within the same statements.

Use the disclosed reconciliation where one is provided. Record the original amount, each explained adjustment and the revised amount. Retain references to the relevant note and page. If the explanation does not reconcile the line you use, ask for clarification before filling the difference with an unsupported assumption.

Check whether related amounts changed too. Revenue, profit, assets, liabilities and equity may be affected differently, and a ratio can depend on more than the line that first drew your attention. Replacing one value in a spreadsheet while leaving its dependent inputs on the old basis can produce a result that belongs to neither reporting version.

Consider an invented example with current-year revenue of $550,000. Last year's originally reported revenue was $500,000, so a calculation using the original figure shows 10% growth. The current statements restate that prior-year revenue to $480,000, and assume for this illustration that the current-year amount remains $550,000.

Using the restated comparative, the increase is $70,000 divided by $480,000, or approximately 14.58%. The change from 10% to 14.58% is caused by the revised starting amount. It does not mean the current year's sales team generated an additional $20,000 after the original calculation was prepared.

Label the two calculations clearly if both matter to the discussion. A presentation explaining what investors previously saw may need the original published figure, while a current like-for-like analysis may use the revised comparative. State the purpose and basis rather than quietly switching between them to support a preferred narrative.

Keep the arithmetic separate from the accounting explanation. The bridge shows how the denominator changed the growth rate. The financial statement note explains why the prior-period figure changed. A useful report gives the reader both pieces rather than treating a recalculated percentage as a complete account of the event.

A chart covering five years may contain several versions of historical information. Identify which periods the current package revises and whether consistent information is available for earlier periods. Do not extend an adjustment backward using an arbitrary percentage simply to make the chart look continuous. Mark a genuine limitation in comparability when the evidence does not support a complete restatement of your analytical series.

Review dependent calculations such as margins, average balances, turnover measures and cumulative growth. An average can combine a revised closing balance with an unrevised opening balance unless you check both. Preserve the formula and source date for each input so the reviewer can see where the different reporting versions enter the analysis.

If a contractual measure or transaction valuation used the earlier figures, refer the issue to the responsible adviser. The agreement may define its own treatment of later corrections. Do not assume that a restatement automatically changes a payment, covenant result or purchase price without reading the relevant terms and obtaining the appropriate interpretation.

Save the original report as historical evidence and identify the current version used for ongoing analysis. This is different from deleting the earlier file. The original document may be needed to explain a previous decision, a communication or a calculation that was reasonable on the information then available.

Update the reports and models that rely on the affected numbers. Keep a short change record identifying the source document, revised fields, dependent calculations and review date. Ask the owner of a recurring dashboard to confirm the change reached the underlying dataset rather than only the latest exported slide.

When communicating the update, explain what changed and why it matters to the analysis. Avoid vague statements that all historical numbers have been corrected if only a defined set of periods or lines was revised. A focused explanation helps readers assess their own use of the earlier information without creating confusion about unaffected figures.

After the immediate update, review how the organization obtains and versions external financial information. A model that stores a number without its source date or reporting basis makes later corrections difficult to trace. Add enough provenance to identify the statement package and note used, while keeping the workflow practical for the team maintaining it.

For the next annual comparison, start with the current package's comparative information and check the relevant notes before importing older values from a prior workbook. Where the analysis intentionally uses originally reported information, say so and explain the reason. Consistency comes from an explicit basis, not from assuming the oldest saved spreadsheet remains authoritative.

The completed analysis should distinguish the change in the business from the change in the measurement of its history. Readers can then understand the current trend, the earlier presentation and the limits of comparison. That is the useful outcome of a restatement review: a traceable series and an explanation that does not turn an accounting revision into an invented operating event.