How does an auditor verify activity data in a GHG inventory?
An auditor checks activity data in three ways. They trace a sample of reported quantities back to invoices, bills and meter readings. They trace a sample of source documents forward into the totals to test completeness. And they reconcile your totals against independent records such as purchase ledgers, stock registers and production.
Step 1: understand how the numbers were built
Before testing anything, the verifier maps the data flow: which documents feed each emission source, who enters them, which spreadsheet or system adds them up, and where factors are applied. ISO 14064-3 calls this assessing the risk of misstatement. Sources that are large, manual or estimated get the most testing.
Step 2: vouching and tracing a sample
- Vouching (testing accuracy): pick reported lines, for example March diesel of 4,200 litres, and find the fuel invoice or slip that supports the quantity, unit, date and site.
- Tracing (testing completeness): pick source documents from the purchase ledger or the discom account, and check each one appears in the inventory in the right month.
- Sample size grows with the size of the source and the level of assurance. Large sources may be tested in full.
Step 3: reconcile to records the carbon team does not control
- Fuel bought per invoices against accounts payable or the general ledger.
- Fuel used against purchases adjusted for opening and closing stock in the store register.
- Electricity units against the discom bills for every connection, including small ones.
- Energy use against production: a month where output rose but kWh fell gets a question.
Step 4: check periods, units and recalculation
Verifiers look for bills that straddle two reporting periods, kVAh read as kWh, kilolitres read as litres, and net-metered units counted as consumption. Then they recalculate a sample: quantity times the stated factor, to the stated rounding. Any difference above their materiality threshold is reported to you as a misstatement to correct.
Worked example: reconciling a year of diesel
- Diesel bought per invoices: 52,000 litres
- Opening stock 3,000 litres, closing stock 5,000 litres
- Diesel used: 52,000 plus 3,000 minus 5,000 = 50,000 litres
- Scope 1: 50,000 x 2.68 kg CO2 per litre (IPCC 2006 default) = 134,000 kg CO2, 134 t
- If the inventory reports 52,000 litres instead, it overstates by 2,000 x 2.68 = 5,360 kg CO2
The stock register is the independent record here; without it, purchases are only a proxy for use.
What Senseible does here
Senseible links every line to its source invoice or bill, records a SHA-256 fingerprint of each file and keeps a hash-chained ledger, so a verifier can vouch and recalculate without hunting for paper. Its Verified status means its own rule checks passed; the sampling, reconciliation and opinion remain the auditor's work.
Sources: ISO 14064-3:2019, Specification with guidance for the verification and validation of GHG statements, SEBI circular on BRSR Core, 12 July 2023, 2006 IPCC Guidelines, Volume 2 Energy (diesel default)
Last reviewed 2026-10-15.