Glossary›Emissions accounting and measurement›Activity data
Glossary term
Cluster D · D11
Tier 1
Activity data
Definition
Activity data is the measured quantity of an activity that causes greenhouse gas emissions: litres of diesel, kilowatt hours of electricity, kilometres travelled, tonnes of material processed, nights of accommodation. It is the input an emission factor is applied to. Every reported emissions figure resolves to an activity quantity and a factor.
AASB S2 Appendix B
· paragraph B45(a) ·
In force
On this page
In practice
Activity data is where almost all first-year effort actually goes, and entities consistently underestimate it because the factor side looks like the technical problem. It is not. Factors are published; you look them up. Activity data has to be extracted from systems that were built for operations, billing or tax, and never for emissions.
AASB S2 names it directly. Appendix B paragraph B45 describes estimation as using two types of input: data representing the entity’s activity that results in emissions, and emission factors that convert that activity data into emissions. The example the standard gives is distance travelled as activity data for transport of goods. That is the whole architecture in one sentence.
Three properties determine whether a piece of activity data survives assurance, and they are worth naming because they are testable before the assurer arrives.
Property
What it requires
How it fails
Unit integrity
The quantity must be in a physical unit that matches the factor.
A fuel figure in dollars is not activity data, it is spend. Converting dollars to litres at an assumed price is legitimate but it is an estimate from that moment, and the assumed price is now a documented judgement.
Period alignment
The quantity must cover the reporting period, no more and no less.
Electricity billing cycles almost never align to a financial year, so a straddling invoice needs an apportionment method that is stated once and applied everywhere.
Entity attribution
The quantity must belong to an entity inside the inventory boundary.
A fuel card held by a group company and used across three subsidiaries needs an allocation rule, not a guess.
The single most common structural failure is not error, it is aggregation. Activity data arrives already summarised (a landlord’s annual outgoings statement, a travel agent’s yearly report, a site manager’s twelve-month spreadsheet) and once it arrives as a total, it cannot be sampled, period-tested or reconciled. Collect it at the transaction or invoice level or accept that the whole line is untestable.
What the assurer does with it
Activity data is where substantive testing lands, because it is the only part of the calculation that is not published. The assurer picks a reported figure, works back to the activity quantity, and asks for the document the quantity came from. They agree three things off that document: the quantity, the period and the legal entity named on it.
They accept a quantity taken from an external document created at the time of the activity, in a physical unit, covering a period that reconciles to the reporting year. They reject a quantity typed into a spreadsheet with no source attached, a quantity derived from a spend figure with no documented price assumption, a quantity covering a different period than the report with no apportionment, and a quantity naming a legal entity that is not in the consolidation. That last one catches groups constantly, because utility accounts are frequently held in the name of a legacy entity nobody has re-papered.
They then test the other direction for completeness. Given a population of sites, meters, vehicles and fuel accounts drawn from the asset register, lease schedule and general ledger, they check that each appears in the activity data. A site with no activity data is a completeness failure, and completeness failures cannot be argued away because there is no counter-evidence to produce.
Commonly confused with
Emissions data. Activity data is the physical input; emissions data is the output after a factor is applied. Entities that describe their spreadsheet as “our emissions data” when it contains litres and kilowatt hours are confusing the two, and it matters because the assurance procedures for each are different. Also confused with spend data, which is a monetary proxy for activity, not activity itself.
Sources
1
2
Greenhouse Gas Protocol: A Corporate Accounting and Reporting Standard (2004 revised edition)
GHG Protocol
Review status
Review required
Last reviewed
15 September 2026
Editorial pass, unsigned
Reviewer required
Carbon accounting specialist
Next scheduled review
1 August 2027
next expected National Greenhouse Accounts Factors release
Part of
Cluster D, Emissions accounting and measurement
49 terms from the head term carbon accounting down to individual Scope 3 categories and the mechanics of factors, boundaries and data quality. The largest cluster in the glossary.
Related terms
The published coefficient the activity quantity is multiplied by
Where the quantity came from, and why the standard prioritises one
What to do where the activity quantity cannot be obtained
Related questions
What evidence do we need for each emissions number?
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Every reported number needs a source document you did not create for the report, the activity data drawn from it, the emission factor and its published edition, and the calculation joining them. Fleet fuel needs litres from fuel card statements, electricity needs kWh by site from retailer invoices with the matching state factor, and refrigerants need kilograms by gas type from service records.
How do we tie our emissions data back to the general ledger?
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You reconcile the spend or volume behind each emissions source to the ledger accounts that record it, and you document the differences. It is not a perfect tie and it is not meant to be. The point is completeness: the ledger is the only population in the business already complete and already audited, so it is the natural control total for showing nothing has been left out.
Can we use spreadsheets, or will the auditor reject them?
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Spreadsheets are acceptable and no Australian standard requires software. What gets rejected is an unauditable spreadsheet: hard-coded numbers with no source, broken formula chains, no version control and no record of who changed what. A disciplined spreadsheet passes assurance and an undisciplined system does not.
Other terms in this cluster
Activity data