If a number saved last year differs from the one in today’s source, first identify the changed document and line item. An amended filing, a reclassification, an estimate change and a company-adjusted performance measure are not interchangeable.
Distinguish document and accounting changes
IAS 8 distinguishes policy changes, estimate changes and error corrections. An amendment title alone does not establish a financial-statement error. Read the stated reason, filing date and changes, then record the affected amount and period.
A fictional revision log
This invented example illustrates how a changed comparison base affects arithmetic.
| Document checked | Prior-year revenue | Current-year revenue |
|---|---|---|
| Originally saved figures | 100 | 120 |
| Revised comparative figures | 105 | 120 |
The first growth calculation is 20%. Using a verified, comparable prior figure of 105 gives (120 − 105) / 105, approximately 14.3%. Preserve the old amount, new amount, document date and stated reason rather than overwriting a spreadsheet cell with no explanation.
Follow the bridge to adjusted earnings
Suppose a fictional business starts with reported earnings of 8 and excludes a cost of 2 to present adjusted earnings of 10. Ask exactly what was removed, whether tax effects were considered and whether similar costs recur. A label such as one-off is not proof that a cost can never return.
For a US non-GAAP measure, read the reconciliation to the closest GAAP measure. The SEC guidance explains that relationship and presentation considerations. FirmLens does not automatically replace standard net income with a company’s adjusted earnings number.
Four checks before comparing again
- Which document changed, and which period does it cover?
- Did an amount change, or just its label or classification?
- Do current and comparative amounts now use the same definition?
- Can you see the original measure and the items excluded from an adjusted one?
If you cannot establish the reason, keep that gap in your notes. A recent collection timestamp does not automatically resolve historical comparability.