Keep a calculation change log that explains the revised result

When a reported figure changes, preserve the old result, identify the changed input or method, calculate its effect and record which outputs must be refreshed. A file name ending in “final revised” does not explain the change or show that someone approved it.

This guide is for ESG reporting preparers and reviewers managing calculations during a reporting cycle. It addresses changes within the calculation record. Formal restatement, filing and base-year recalculation requirements need a separate decision under the applicable framework.

Classify the change before editing

Use a reason that identifies what happened:

• Source correction: an invoice, extract or recorded quantity was wrong or incomplete.

• Calculation correction: a formula, conversion, mapping or aggregation rule was applied incorrectly.

• Method or factor change: the calculation basis, source factor or other methodological input changed.

• Boundary or period change: the operations, population or dates included changed.

• Presentation change: rounding, labels or display changed without changing the underlying basis.

These are suggested internal categories. Several can apply to one revision. Separate them where possible so an increase caused by a corrected quantity is not described as a change in operational performance.

Record the before and after state

A useful change entry contains:

1. Change ID, date, preparer and affected metric

2. Entity, site, reporting period and boundary version

3. Old source/input, method and result, with file and cell references

4. New source/input, method and result

5. Reason and supporting evidence

6. Calculated effect, original unit and reporting unit

7. Affected schedules, charts, narratives and previously shared outputs

8. Reviewer, approval status and release version

9. Decision on comparative periods, disclosure or external correction

Store original source records separately from the changed calculation. Avoid overwriting a shared factor cell without recording which rows use it. If a correction is rejected, retain its proposed treatment and the reason for rejection.

Use the Calculation change and correction register to record old and new result references, the reason for the revision, review decisions and dependent-output checks. Record the release reference and date so the next reviewer can follow the change through to the revised reporting version.

A hypothetical revision with no net movement

Fictional teaching example, not a Nitium client case. All figures concern one electricity line for the same reporting period. Both emission factors below are invented for arithmetic and must not be used in a real inventory.

• Version 1: 240,000 kWh × 0.50 kg CO2e/kWh ÷ 1,000 = 120 tonnes CO2e.

• Quantity correction: a supported missing line increases activity to 250,000 kWh. At the same factor, the result is 125 tonnes CO2e: a change of +5 tonnes.

• Factor revision: assume the appropriate reviewer separately approves 0.48 kg CO2e/kWh for the stated purpose. Using the corrected quantity, the result becomes 120 tonnes CO2e: a further change of −5 tonnes.

The final total equals version 1, but two substantive changes occurred. The change log records them separately, along with the factor-selection decision and its source. “No change to the total” would conceal the corrected activity data and revised method input.

This is a revision bridge in a stated order: quantity first, factor second. A different order can allocate the interaction differently, so record the sequence when explaining individual effects. None of these revisions establishes a real-world emissions reduction.

Retest the dependencies

Use the change entry to locate everything that depends on the revised item. Check totals, intensity denominators, charts, comparison tables and narrative claims. Recalculate a sample independently and test the corrected formula against the error it was meant to fix.

Before release, compare the final disclosure with the approved schedule. A spreadsheet can be correct while an exported PDF or customer response still carries the previous value.

Decide what must be disclosed or revisited

For BRSR Core, SEBI's framework addresses disclosure of methodology changes, industry-specific adjustments and estimates. Source: SEBI master circular, chapter IV-B, paragraph 2.2.

For a GHG inventory, examine the applicable recalculation policy when changes affect historical comparability. The GHG Protocol Corporate Standard, chapter 5 distinguishes significant structural or methodological changes and errors from real changes in emissions. A newly released factor does not automatically justify replacing every historical factor.

Assign the reporting owner to determine the treatment of prior disclosures and any required notifications. The change log supports that decision; it is not itself an authorisation to amend a filing or publish a correction.

Close the change only when the trail is complete

• The old and new states can be reconstructed

• The reason and evidence are recorded

• The effect has been independently checked

• Dependencies and narrative statements have been refreshed

• Historical-period and disclosure decisions are documented

• The approved release and superseded version are identifiable

Our BRSR evidence-file guide connects the log to source records. Nitium's ESG readiness support can help review calculations and evidence gaps before an independent engagement. Discuss a calculation-review task or email contact@nitium.in.

Sources checked 5 October 2026. This workflow does not determine materiality, prescribe a universal recalculation threshold or provide independent assurance. The fictional factors are not reporting inputs.