Close to half (46%) of FTSE 100 companies in the UK made material prior-year adjustments (PYAs) to their climate and sustainability metrics in 2025, Deloitte has reported, the second year in a row in which widespread revisions have been made.
According to Deloitte, more than three quarters of these PYAs related to greenhouse gas metrics, with the remainder (23%) covering areas such as waste, water use, diversity and inclusion, and health and safety.
Multiple adjustments
‘While the total number of companies making adjustments remained unchanged, analysis showed that six more companies made multiple adjustments this year, resulting in a total of 69 individual adjustments,’ Deloitte noted.
In 2024, greenhouse gas revisions accounted for a higher proportion of PYAs, at 89%. Some 25 of the FTSE 100 firms that reported a PYA last year did so again this year.
“Our analysis shows that these adjustments are now a regular feature of FTSE 100 climate reporting,” commented Steve Farrell, partner and head of sustainability assurance at Deloitte UK.
“Whilst the number of companies with material adjustments is the same as last year, this remains a significantly high amount, with continued challenges in getting sustainability reporting right. However, some of these companies have adjusted due to data improvements – that’s a real positive – showing reporters are focusing on better quality reporting.”
Farrell added that the high proportion of restatements relating to emissions was “reflective of the continued focus on improving reported GHG information”.
The most common reason for a PYA was a change in method (35%), the study found, although this was down from 44% in 2024. Adjusting for errors in historical reporting was cited by 26% of firms, compared to 29% last year.
Challenges ahead
“There are many challenges when it comes to sustainability reporting, and sustainability restatements are likely to continue for the foreseeable future,” added Emily Hesketh, sustainability assurance partner at Deloitte UK.
“Caution is needed by the users of the information – including regulators, investors, and customers – when relying on the reported data to understand the progress companies are making to meet their targets.” Read more here.
