Substantial rise in companies making sustainability adjustments in 2025

• More than two thirds (69) of the FTSE 100 made restatements on their sustainability metrics in 2025, rising for the third consecutive year;
• Restatements due to errors have decreased to 20% (from 26% last year);
• Scope 3 emissions make up a significant portion of the restatements;
• 86 of the FTSE 100 are obtaining sustainability assurance.

More than two thirds (69%) of FTSE 100 companies made prior-year adjustments (PYAs) to their climate and sustainability metrics – a significant increase from 46% last year –according to an analysis by Deloitte UK. Notably, the number of companies disclosing multiple PYAs tripled to 51 companies (17 companies last year).

Now in its third year, the latest analysis looked at climate and sustainability disclosures in the most recently published annual reports as of 31 December 2025. The drivers for PYAs have also evolved from previous years, with a 23% decrease in error-driven PYAs.

Steve Farrell, partner and head of sustainability assurance at Deloitte UK, said: “With adjustments increasing for the third year in a row, this recent data shows us they have become a core feature of FTSE 100 climate reporting. The decrease in error-driven misstatements indicates improvement in reporting quality, particularly as restatements due to changes in methodology, business structure and other factors, have increased significantly. This suggests a positive step from UK companies towards refining reporting processes and data quality, rather than merely correcting mistakes.”

Of the restatements made, the majority (65%) related to greenhouse gas (GHG) emissions, with the remainder (35%) comprised of a variety of other sustainability topics (including waste, water, diversity & inclusion, and health & safety). In comparison, last year 77% related to GHG emissions. Of the 59 companies who had PYAs relating to GHG emissions, 44 (75%) had PYAs related to Scope 3 emissions.

Farrell added: “The high volume of restatements indicates that companies are actively working to improve the accuracy and reliability of their Scope 3 reporting. It underscores the inherent challenges and complexities associated with collecting, calculating and assuring the data.”

Alongside this, 86 FTSE 100 companies publicly stated that they obtained assurance over sustainability metrics in 2025, increasing from 84 the previous year and 74 in 2023. ISAE 3000 continues to be the dominant assurance standard, with 79% limited or reasonable assurance under ISAE 3000.

ENDS