> For the complete documentation index, see [llms.txt](https://www.bilancarbone-methode.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://www.bilancarbone-methode.com/english/4-accounting/4-introduction-a-la-comptabilisation-des-emissions.md).

# 4 - Introduction to emissions accounting

<figure><img src="/files/JjuoqUnGvm3mOtIFBiS4" alt="" width="375"><figcaption><p>Source: Freepik</p></figcaption></figure>

[Accounting](/english/annexes/glossaire.md#comptabilisation) is defined as the process of collecting and processing the various data needed to carry out a Bilan Carbone®.

{% hint style="info" %}
For each emission source of the organisation, the emissions to be accounted for are estimated as follows:

Emission from a source = [Activity data](/english/4-accounting/4.2-methode-de-collecte-des-donnees-dactivite.md) x [Emission factor](/english/4-accounting/4.3-methode-de-selection-des-facteurs-demission.md) = [Result](/english/4-accounting/4.5-profil-demission.md) ± [Uncertainty](https://github.com/ABC-TransitionBasCarbone/methode-bilan-carbone/blob/translated-en/4-comptabilisation/4.4-methode-destimation-des-incertitudes)
{% endhint %}

These different components of the calculation are detailed step by step:

* Step [4.1](/english/4-accounting/4.1-methode-de-quantification-des-emissions.md): presenting the general principles of accounting.
* Step [4.2](/english/4-accounting/4.2-methode-de-collecte-des-donnees-dactivite.md): framing the collection of activity data.
* Step [4.3](/english/4-accounting/4.3-methode-de-selection-des-facteurs-demission.md): framing the selection of emission factors.
* Step [4.4](https://github.com/ABC-TransitionBasCarbone/methode-bilan-carbone/blob/translated-en/4-comptabilisation/4.4-methode-destimation-des-incertitudes): framing the estimation of uncertainties.
* Step [4.5](/english/4-accounting/4.5-profil-demission.md): drawing up the organisation's emission profile.

These calculation components are documented and retained by the organisation.

<div data-full-width="true"><figure><img src="/files/TOCsRt9tsTlvh1bORC26" alt=""><figcaption><p>Figure 4: Timeline of the accounting stage</p></figcaption></figure></div>

<mark style="color:$info;">🌐</mark> [*<mark style="color:$info;">English version</mark>*](https://abc-transitionbascarbone.fr/wp-content/uploads/2025/11/Timeline-of-the-accounting-stage_Chronologie-de-letape-de-comptabilisation-scaled.png) *<mark style="color:$info;">of this image.</mark>*

## Glossary relating to the Accounting stages

All terms relating to the accounting stages are explained in the [glossary](/english/annexes/glossaire.md). They are recalled below:

* Activity data: Quantitative measure of a given activity that gives rise to the emission or removal of GHGs. Activity data (AD) may be real (physical or financial), extrapolated, statistical or approximate.
* Emission factor: Coefficient relating activity data to GHG emissions. An emission factor (EF) may come from databases, be developed by the organisation, or be a coefficient expressed as "Spend-based emission factors" (specific or non-specific).
* Uncertainty: Parameter associated with the result of a quantification that characterises the dispersion of values that can reasonably be attributed to the quantity being quantified.
* Data collection matrix: A summary of all the activity data and emission factors used during the accounting process, serving as documentation for the organisation (sources, assumptions, uncertainties, value and unit).
* Emission profile: Aggregation of the results of quantified GHG emissions, for all emission sources included within the [perimeters](#p) of the organisation.

  The emission profile also refers to the breakdown of quantified emissions according to a certain nomenclature (for example, according to the Bilan Carbone® [emission categories](#p)).

## Governance relating to the Accounting stages

The governance of the accounting stage is part of the [overall governance](/english/1-scoping-the-approach/1.2-definir-le-pilotage-de-la-demarche-bilan-carbone-r.md) of the Bilan Carbone® approach presented previously.

The governance of this stage does not differ according to the maturity levels of the organisation. In all cases, project officers or external service providers are responsible for collecting data from the organisation's staff, with the help of the coordinator if needed. Once the data has been collected, these same project officers or external service providers select the emission factors, quantify the uncertainties, and obtain the balance result along with the desired associated exports.

Management does not need to be involved during this stage, unless access to certain data requires their approval.

## Stakeholder engagement relating to the Accounting stages

Two stakeholder engagement actions take place during the accounting stages, and are part of the stakeholder engagement programming [presented previously](https://github.com/ABC-TransitionBasCarbone/methode-bilan-carbone/blob/translated-en/3-mobilisation-des-parties-prenantes/3.1-programmer-les-phases-de-mobilisation).

* one upstream of stage 4, i.e. [at the launch of the data collection](/english/3-stakeholder-engagement/3.1-programmer-les-phases-de-mobilisation/3.1.2-au-lancement-de-la-collecte-des-donnees.md)
* the other downstream of stage 4, from the [construction of the emission profile](/english/3-stakeholder-engagement/3.1-programmer-les-phases-de-mobilisation/3.1.3-a-lissue-de-la-construction-du-profil-ges.md), therefore for the interim presentation.

## Requirements relating to the Accounting stages

As a **reminder**, here is the [summary of requirements](/english/1-scoping-the-approach/1.1-definir-son-niveau-de-maturite-bilan-carbone-r.md#comparatif-des-criteres-des-niveaux-de-maturite-pour-lamelioration-continue-du-bilan-carbone-r) and recommendations for each maturity level. These criteria are explained in detail in the following sub-sections.

{% tabs %}
{% tab title="Initial Level" %}

#### Accounting:

* K: Data collection methods
  * K1: All activity data collection methods are accepted.
* L: Spend-based emission factors
  * L1: The share of emissions calculated using spend-based emission factors (specific and non-specific) is reported. The use of non-specific Spend-based emission factors is justified.
* M: Uncertainties
  * M1: The organisation must qualify and quantify the uncertainties for all direct GHG emissions and significant indirect emissions of the Bilan Carbone®. The organisation determines the uncertainty by assigning a score to each relevant activity data point and emission factor.
* N: Emission profile
  * N1: The emission profile is presented at a minimum according to the Bilan Carbone® nomenclature.
    {% endtab %}

{% tab title="Standard Level" %}

#### Accounting:

* K: Data collection methods
  * K2: Statistical data, extrapolated data and approximate data are framed, justified, and their use is limited.
* L: Spend-based emission factors
  * L2: The share of emissions calculated using spend-based emission factors (specific and non-specific) is reported. The use of non-specific Spend-based emission factors is very tightly controlled and justified.
* M: Uncertainties
  * M2: The organisation must qualify and quantify the uncertainties for all direct GHG emissions and significant indirect emissions of the Bilan Carbone®. The organisation determines the uncertainty by assigning a score to each relevant activity data point and emission factor.
* N: Emission profile
  * N2: The emission profile is presented at a minimum according to the Bilan Carbone® nomenclature.
    {% endtab %}

{% tab title="Advanced Level" %}

#### Accounting:

* K: Data collection methods
  * K3: Statistical data, extrapolated data and approximate data are framed, justified, and their use is limited.
* L: Spend-based emission factors
  * L3: The share of emissions resulting from a calculation using specific and non-specific spend-based emission factors is reported. The use of non-specific Spend-based emission factors is justified, or even excluded. The organisation has developed specific emission factors for key emission categories.
* M: Uncertainties
  * M3: The organisation must qualify and quantify the uncertainties for all direct GHG emissions and significant indirect emissions of the Bilan Carbone®. The organisation determines the uncertainty of activity data and emission factors according to 5 characteristics (technical, geographical, and temporal correlation, completeness, and reliability).
* N: Emission profile
  * N3: The emission profile is presented at a minimum according to the Bilan Carbone® nomenclature.
    {% endtab %}
    {% endtabs %}

## Deliverables relating to the Accounting stages

The information and deliverables obtained at the end of stage 4, and associated with the above requirements, are to be [reported](/english/6-summary-and-reporting/6.1-restitution-du-bilan-carbone-r.md) at the end of the approach:

* [x] The [data collection matrix](/english/4-accounting/4.2-methode-de-collecte-des-donnees-dactivite.md#matrice-de-collecte-des-donnees) (summary of data collected as well as a description of the data collection process followed; documentation of the emission factors used, and of the spend-based emission factors (specific and non-specific) as well as their sources);
* [x] The uncertainties associated with the organisation's emission profile;
* [x] The Spend-based emission factor usage rate (specific and non-specific) associated with the organisation's emission profile;
* [x] The organisation's emission profile, listing emissions in tCO2e.

***

*Do you have a comprehension question?* [*Consult the FAQ*](/english/annexes/faq.md)*. The method is living and therefore subject to change (clarifications, additions): find the* [*change log here*](/english/readme/historique-et-suivi-des-modifications.md)*.*


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