What ESRS‑40a means for UK businesses left out of the CSRD simplification narrative

Estimates now suggest around 80 percent of companies originally expected to report under the Corporate Sustainability Reporting Directive may no longer fall within scope following the EU's Omnibus reforms. For many communications teams and sustainability managers, that headline has landed as straightforward good news: fewer obligations, less complexity, less cost. The reality for UK businesses operating in European markets or supply chains is considerably more layered than that reading suggests.

The emerging discussion around ESRS-40a points to a segmented approach to sustainability reporting rather than a wholesale simplification. Rather than one uniform standard covering all companies, the reform trajectory appears to be moving toward differentiated requirements based on company size and market exposure. UK businesses that supply into European value chains, or that have operations touching EU regulated entities, may find themselves drawn into reporting expectations even without a direct CSRD obligation of their own.

For procurement leads and in house ESG managers, the practical implication is that simplification at the top of the regulatory pyramid does not necessarily mean simplification at the supplier level. Large EU listed companies still subject to CSRD will continue to request sustainability data from their supply chains to complete their own disclosures under ESRS standards including ESRS E1 on climate and ESRS S1 on the workforce. UK suppliers providing that data face the same granularity of request regardless of whether they themselves are in or out of CSRD scope.

The segmentation dynamic also creates a compliance planning challenge. UK businesses that assumed Omnibus would remove their exposure to EU sustainability reporting frameworks may need to reassess, particularly if their largest customers remain within the revised CSRD perimeter. The question is no longer simply whether a company is in scope, but whether its customers and counterparties are, and what data those counterparties will need to fulfil their own obligations.

The broader picture is one where regulatory simplification and market driven reporting demands are pulling in different directions. Formal scope reductions under CSRD do not automatically reduce the informal pressure on suppliers to provide emissions and sustainability data. ESG managers tracking the ESRS-40a development should watch for further technical guidance on exactly which disclosures will be required under any segmented standard, and how those requirements map onto what EU customers are already asking for.