What are GHG accounting principles?
Greenhouse gas (GHG) accounting principles are five tests for the choices behind a company inventory: relevance, completeness, consistency, transparency, and accuracy. Chapter 1 of the GHG Protocol Corporate Standard says they underpin every part of accounting and reporting, especially when the standard does not give one obvious answer for your situation.
Why do GHG accounting principles matter to you?
A customer, investor, or reviewer may ask why you included one subsidiary, left out one source, changed one factor, or estimated one month. Keep a method note that states what the inventory is for, which companies and sites it covers, the reporting period, the source list, factor versions, exclusions, assumptions, changes, and who reviewed it. Those records show why the total can be trusted.
How do GHG accounting principles work?
Relevance asks whether the boundary and results serve the decisions of internal and external users. Completeness asks whether every source and activity inside that boundary is counted, with each exclusion disclosed and justified. The Corporate Standard warns against using a preset materiality threshold to omit a source before you have quantified it.
Consistency keeps boundaries and methods comparable over time. If you change a factor, data source, boundary, or method, record the change and its effect on figures for prior years. Transparency means keeping a clear trail from each total back to its source records, calculations, assumptions, and references. Accuracy means checking for repeated bias that pushes emissions too high or too low and reducing uncertainty as far as practicable. It does not mean pretending every estimate is exact.
Apply the five tests to each important inventory choice before final review. If a utility bill is missing, record why that source belongs in the inventory, how you filled the gap, whether you used the same method in prior periods, which records support the estimate, and what check guards against bias.
What mistakes should you avoid?
- Treating the five principles as separate scores when one decision can satisfy one principle and weaken another.
- Dropping a source because it looks small without first quantifying it or documenting and justifying the exclusion.
- Calling a method consistent because it never changes, even when the data source or calculation is no longer appropriate.
- Calling an estimate accurate without recording the source, unit, assumption, calculation, uncertainty, and review check.
Does completeness mean every number must be measured?
No. The Corporate Standard recognizes that data may be missing or too costly to collect, but you must document and justify missing or low-quality estimates. Keep a list of each gap with the source, reporting period, missing record, substitute method, result, and approver.
Can you change a method and still be consistent?
Yes. Consistency means preserving a meaningful comparison, not freezing a weak method. Record the old and new method, the date of change, the affected inventory lines, and the effect on prior figures. Then follow your written policy for recalculating the base year, which is the reference year used for comparison. Apply it if the change is large enough to meet the threshold stated in that policy.
Are these five principles still current?
Yes. GHG Protocol said the existing standards remain in effect until it releases revised guidance. Its 29 July 2026 update says a consolidated GHG Protocol and ISO corporate standard is planned for the fourth quarter of 2028. Check the standard-setting page before each annual inventory in case the timetable or requirements change.