GRI Reporting Frequency

GRI frequency recommendations — what the Standards say

GRI 1 (Foundation 2021) states that organisations report on a regular cycle — typically annual — aligned with the financial reporting cycle. This is a recommendation, not a mandatory requirement. GRI does not penalise companies that report biennially or on other cycles.

However, the market expectation has shifted toward annual reporting — particularly for large companies. ESG rating agencies (MSCI, Sustainalytics) update their assessments based on annual data releases. CDP requests annual climate data. Institutional investors track year-on-year sustainability performance. A company that reports only every two years becomes increasingly data-dark in ESG analyses between reports.

For companies transitioning from voluntary GRI to mandatory CSRD: CSRD mandates annual reporting with no exceptions. If you have been reporting GRI biennially, CSRD compliance requires building the systems and capability for annual data collection — a significant operational change. Use your final biennial GRI report as the baseline and establish annual collection processes before your first mandatory CSRD report.

Reporting period alignment: GRI recommends aligning the sustainability reporting period with the financial reporting period — typically the fiscal year. This enables direct comparison between financial and sustainability performance and simplifies the narrative connecting the two. Where the sustainability report covers a different period from the financial statements, explain the rationale clearly.

Managing year-on-year data consistency

Year-on-year comparability is a core principle of credible sustainability reporting — stakeholders need to track performance trends, not just point-in-time snapshots.

Comparative data: GRI recommends providing at least one year of prior period comparatives for all quantitative metrics. For metrics where methodology or scope has changed, provide restated comparative data alongside the current year figure — showing both the original reported figure and the restated figure with explanation.

Methodology changes: When you change a calculation methodology (for example, updating from IPCC AR4 to AR6 GWP values for GHG reporting), you must decide whether to: restate prior year figures to the new methodology (preserving comparability); or disclose both old and new methodology figures for the transition year; or disclose only current year under new methodology with clear explanation of the change.

Organisational boundary changes: Acquisitions, divestitures, and outsourcing that change the organisational boundary create GHG Protocol base year restatement obligations — and equivalent restatement obligations for other metrics. A major acquisition that adds 20% to your employee headcount requires restating prior year headcount data to the new boundary for meaningful comparability.

For CSRD companies: ESRS requires prior year comparative data for all quantitative disclosures. If your GRI report has consistently provided comparative data, this is a natural transition to ESRS. If your GRI reporting has been inconsistent on comparatives, CSRD is the forcing function to establish robust comparative data practices.

Updating and correcting GRI reports

Unlike financial statements, GRI sustainability reports do not have a formal restatement process with regulatory notification requirements. However, material errors should be corrected — and the process for doing so should be transparent.

Error correction: Where a significant error is identified in a published GRI report — for example, a Scope 3 calculation error that overstated or understated emissions by more than 10% — publish a correction on your website and note it in the subsequent year's report. Reference the correction in the GRI Content Index with the relevant disclosure.

Restatement vs update: A restatement recalculates prior period figures to correct errors or reflect methodology/boundary changes. An update provides additional information on a topic without correcting prior figures. Both should be disclosed transparently in the current year report.

For CSRD: Once CSRD reporting begins, corrections and restatements must follow ESRS 1 requirements — including assurance re-engagement where the restatement is material. The regulatory scrutiny of CSRD restatements is significantly higher than for voluntary GRI corrections. This is additional incentive to invest in data quality before first CSRD filing rather than relying on post-publication corrections.

Frequently asked questions