Collecting ESG data across a group

Most groups first collect ESG data the hard way: a spreadsheet emailed to every site in January, chased for weeks, with each site interpreting the questions differently. That does not survive mandatory reporting, assurance and a publication date tied to the annual report. This guide explains how to set the reporting boundary, what a group ESG reporting manual contains, works through a group's ESG close, and covers tools, estimates, acquisitions and how ESG reporting fits with the financial close.

By Muhammad Bilal, Chartered Accountant. Reviewed by Awais Jameel, Chartered Accountant. 4 minute read.

Short answer

Collecting ESG data across a group means gathering consistent environmental, social and governance figures from every subsidiary and site, in time to publish them with the annual report. It starts with the reporting boundary: under the ESRS and IFRS S1, the same group as the consolidated financial statements, with greenhouse gas emissions consolidated using a GHG Protocol approach such as operational or financial control. A group reporting manual then defines each metric, its unit, method, data source and owner. Local data owners collect the figures, usually quarterly or monthly, in a central tool rather than in spreadsheets sent by email; missing or late data is estimated with a documented method and trued up later; and the group team checks, consolidates and reviews the results, with variance analysis and sign-off. Because a CSRD sustainability statement sits in the management report, and IFRS S1 disclosures are published with the financial statements, the ESG timetable must fit the financial close: many groups collect actual data to the end of the third quarter, estimate the last months, and replace the estimates with actuals the following year. Controls and an audit trail at each step make the figures ready for assurance. In this guide's example, a group with 40 subsidiaries runs its ESG close in five stages.

At a glance

Boundary
Same as the accounts
Manual
Defines each metric
Owners
One per metric and site
Collection
Quarterly, in one tool
Year end
Estimate, then true up
Goal
Assurance-ready data
Collecting ESG data across a groupBoundary: Same as the accounts; Manual: Defines each metric; Owners: One per metric and site; Collection: Quarterly, in one tool; Year end: Estimate, then true up; Goal: Assurance-ready data.KEY FACTS AT A GLANCECollecting ESG data across a groupBoundarySame as the accountsManualDefines each metricOwnersOne per metric and siteCollectionQuarterly, in one toolYear endEstimate, then true upGoalAssurance-ready dataTax BakersCollecting ESG data across a groupBoundary: Same as the accounts; Manual: Defines each metric; Owners: One per metric and site; Collection: Quarterly, in one tool; Year end: Estimate, then true up; Goal: Assurance-ready data.KEY FACTS AT A GLANCECollecting ESG data across a groupBoundarySame as the accountsManualDefines each metricOwnersOne per metric and siteCollectionQuarterly, in one toolYear endEstimate, then true upGoalAssurance-ready dataTax Bakers
Key facts at a glance, as set out in this guide.

What is the reporting boundary?

Under the ESRS and IFRS S1, sustainability information covers the same reporting entity as the financial statements, normally the parent and its subsidiaries, extended to the value chain where needed to cover material impacts, risks and opportunities. For greenhouse gas emissions, the group chooses a GHG Protocol consolidation approach, operational control, financial control or equity share, and applies it consistently, deciding in particular how joint ventures and associates are treated. The site list should be reconciled to the legal entities in the accounts every year. See organisational boundaries and ESRS 1 general requirements.

What goes in a group ESG reporting manual?

  • A definition of every metric, referenced to the ESRS, GRI or SASB definition it follows, with its unit and calculation.
  • Central conversion and emission factors, so sites do not choose their own.
  • Estimation methods for missing data, and the cut-off rules for the reporting period.
  • Thresholds below which small sites may be estimated rather than measured.
  • Roles: a data owner for each metric at each site, a reviewer, and a group metric owner.
  • The timetable, the tool to use, and the evidence each site must keep.

See ESG KPIs explained.

Collecting ESG data in practice: a group's ESG close

An industrial group with 40 subsidiaries and 120 sites publishes its sustainability statement with its annual report at the end of February.

A group's ESG close for a calendar yearA group's ESG close for a calendar year1PrepareSeptemberUpdate manualand site list2CollectQ1 to Q3Actuals in thecentral tool3EstimateQ4Run rate andknown changes4ReviewJanuaryVariances andsite sign-off5ReportFebruaryConsolidate,assure, publish
Estimates for the last quarter let the group publish with its annual report.

Sites enter actual energy, water, waste, safety and headcount data each quarter in the group's ESG platform, which checks units and flags movements of more than 10%. For October to December, the group estimates energy from each site's run rate, adjusted for a plant that closed in November, because final invoices arrive too late. In January, site managers sign off their data and the group team reviews variances and consolidates. The following year, actual fourth-quarter data replaces the estimates and the group shows the revised comparative figures, explaining the change. See internal controls over sustainability data.

Which tools work best?

Spreadsheets are cheap but fragile: formulas break, versions multiply and there is no audit trail. Dedicated ESG data platforms provide forms, validation rules, workflow, approvals and logs, and can take data directly from energy management, HR, payroll and finance systems. Whatever the tool, restrict who can change data and factors, keep evidence attached to each figure, and test the calculations when the tool is set up. See managing a GHG inventory.

How should estimates be handled?

Estimates are unavoidable at year end and for value chain data, but they should follow a documented method, be applied consistently, be flagged in the data so their share is known, and be replaced with actuals when available. The ESRS allow estimates, sector averages and proxies, and require companies to explain significant measurement uncertainty. See scope 3 supplier-specific data and the value chain cap.

How do acquisitions and disposals affect the data?

An acquired subsidiary is included from the date the group gains control, as in the financial statements, and a disposed one up to the date control is lost; the ESRS allow some relief where data for a recent acquisition is not yet available. For targets and trends, the GHG Protocol requires the base year to be recalculated when structural changes are significant. Build the new entity's data into the manual and tool as part of the integration plan. See GHG base year recalculation.

How does the ESG close fit with the financial close?

Under the CSRD the sustainability statement is part of the management report, and IFRS S1 requires sustainability-related financial disclosures to be published at the same time as the related financial statements, with first-year relief. ESG data therefore has to be ready on the financial close timetable. Aligning the two closes, with shared calendars, the same entity list and finance-style review, also makes the information consistent with the accounts. See connecting sustainability disclosures with the financial statements.

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Questions people ask

What boundary should group ESG data cover?

The same reporting entity as the consolidated financial statements, extended to the value chain where needed, with emissions consolidated using a GHG Protocol approach.

What is an ESG reporting manual?

A group document defining every metric, unit, method, factor, estimation rule, owner, timetable and evidence requirement, so all sites report consistently.

How do groups meet year-end deadlines for ESG data?

Many collect actual data to the end of the third quarter, estimate the final months with a documented method, and replace the estimates with actuals the following year.

When must ISSB disclosures be published?

IFRS S1 requires them at the same time as the related financial statements, with relief in the first year of reporting.

Sources

Every fee, date and rule on this page was taken from these official and primary sources.

  1. EFRAG Knowledge Hub: revised ESRS 1 General requirements, delegated act version
  2. GHG Protocol Corporate Accounting and Reporting Standard
  3. IFRS Foundation: IFRS Sustainability Disclosure Standards (IFRS S1 and IFRS S2)
  4. COSO: Achieving Effective Internal Control over Sustainability Reporting (ICSR), March 2023, announced by The IIA
  5. Garrigues: EU publishes voluntary sustainability standard and caps value chain reporting requirements, September 2026

Rules and fees change. If you are reading this long after October 14, 2026, confirm the figures with the source before you rely on them.

SustainabilityInternal controls over sustainability dataSustainabilityOrganisational boundaries: equity share or controlSustainabilityBuilding a GHG inventory: data and controls

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This guide is general information. It is not tax or legal advice for your situation.