# The verifier asks to see our calculation workings. What should we hand over?

Canonical: https://senseible.earth/answers/verifier-asks-for-calculation-workings

A file or report showing, for each source, the activity data, unit, factor, any conversion and the result, with a reference to the bill or invoice behind each figure. Totals should add up, and any estimate should be marked with its method.

## For each line

- Activity data and unit.
- Emission factor and source.
- Conversions such as litres to kilograms.
- Result in kg or tonnes CO2e.

## Traceability

Each line should point to its source document, so the verifier can sample and recalculate.

## Estimates

Missing data filled by estimate needs a short note on the method and the share of the total it covers.

## What Senseible does here

Senseible keeps each record with its source document, fingerprint, factor and method version, so a verifier can trace any figure back to the bill it came from.

- [Estimation note for the verifier](https://senseible.earth/answers/estimation-note-for-verifier)
- [How auditors verify activity data](https://senseible.earth/answers/how-auditors-verify-activity-data)
- [Materiality in verification](https://senseible.earth/answers/what-is-materiality-in-ghg-verification)

Sources: [ISO 14064-3, validation and verification of GHG statements](https://www.iso.org), [GHG Protocol Corporate Standard](https://ghgprotocol.org/corporate-standard)

Last reviewed 2026-10-22.