Sustainability reporting after the Omnibus: measure before you report

Directive (EU) 2026/470, known as Omnibus I, entered into force on 18 March 2026. It narrows the Corporate Sustainability Reporting Directive (CSRD) to EU undertakings with more than 1,000 employees and more than €450 million in net turnover, with both tests applying together. Non-EU groups come into scope above €450 million of EU turnover where an EU subsidiary or branch generates more than €200 million. Listed small and medium-sized companies are no longer required to report.

The timetable moved as well. EU companies newly in scope report in 2028 on financial year 2027, and non-EU parents report in 2029 on financial year 2028. Member states must transpose the changes by 19 March 2027. The Commission adopted revised European Sustainability Reporting Standards on 3 July 2026, with fewer mandatory datapoints, to apply from financial year 2027. Double materiality remains, and assurance stays at limited level.

The Corporate Sustainability Due Diligence Directive (CSDDD) now covers EU companies with more than 5,000 employees and more than €1.5 billion of worldwide turnover, and non-EU companies with more than €1.5 billion of EU turnover. It applies from 26 July 2029, the obligation to adopt a climate transition plan has been deleted, and the harmonised EU civil liability regime has gone.

For most mid-market firms, the direct reporting obligation has disappeared or moved several years away. The data requests have not.

The UK government published the UK Sustainability Reporting Standards, UK SRS S1 and S2, in February 2026. They are the UK-endorsed versions of the ISSB standards, with some differences, including no first-year relief allowing sustainability disclosures to be published later than the financial statements.

On 30 September 2026 the Financial Conduct Authority published its final rules for listed companies. They require reporting against UK SRS on a comply or explain basis for accounting periods beginning on or after 1 January 2027, with first reports in 2028. Transitional reliefs allow one year for Scope 3 emissions disclosures and two years for the wider disclosures under UK SRS S1. The FCA rules apply to listed companies. Any requirement for private companies would come through separate government legislation.

A UK-listed company with an EU subsidiary may face both regimes. The standards share a climate core but differ on materiality, since UK SRS follows the ISSB's investor focus and the ESRS keep double materiality. One measured dataset can serve both, while two separately estimated ones will disagree with each other.

The Omnibus protects smaller companies in the value chain. Companies with up to 1,000 employees can decline requests from reporting customers that go beyond the voluntary standard for SMEs, and the Commission adopted that standard as a delegated act on 3 July 2026, alongside the revised ESRS.

The cap limits the questionnaire and leaves it in place. Customers in scope will still ask, and the voluntary standard's basic module covers energy consumption and greenhouse gas emissions. Lenders, insurers and public tenders set their own requirements. A supplier that answers with spend-based estimates gives a figure that cannot change when its operations change. If it switches carrier, insulates a building or cuts empty running, the reported footprint stays where it was, because nothing in it was measured.

That is the commercial problem with estimates. A buyer comparing suppliers cannot tell a supplier that has improved from one that has not.

Emissions figures are turning into cost inputs before most firms are required to publish them. Under the EU Carbon Border Adjustment Mechanism, an importer of covered goods can use verified actual emissions from the producing installation, or fall back on default values, and the choice changes the number of certificates bought. Certificates for 2026 imports go on sale on 1 February 2027. The UK mechanism starts on 1 January 2027. Under the EU Emissions Trading System, shipping companies surrender allowances for 100% of reported emissions from 2027, and carriers pass that cost on in surcharges.

In each case a business with measured data has something to negotiate with. An importer with verified installation data from its supplier can compare that with the default values. A shipper with shipment-level transport emissions can test a carrier's surcharge against the fuel and distance actually used. ISO 14083, published in March 2023, sets a common method for quantifying and reporting greenhouse gas emissions from freight and passenger transport chains, so carrier figures and the shipper's own records can be compared on the same basis.

For reporting teams the narrower scope is relief. For operations and procurement, the more useful reading is that the same energy and logistics data now pays back through procurement and freight negotiations, years before any report falls due.

The baseline starts with records, not surveys. Electricity and gas come from meter readings or half-hourly data where available, and from invoices where not, by site and by month. Vehicle fuel comes from fuel card transactions by vehicle. Freight comes from shipment records with weight, origin, destination, mode and carrier, which the transport management system or the forwarder's portal usually holds. Packaging comes from specifications and weights per product. Purchased goods with a carbon price attached, such as CBAM goods, need installation data from the supplier.

Each line keeps its source document and the date it was captured, so an assurance provider, a customer or a lender can trace any reported figure back to a meter, an invoice or a shipment. Gaps are listed and estimated openly, with the estimation method stated, and replaced with measured data as it arrives.

The team that builds the dataset should also work on the changes it reveals, such as route planning, load fill, carrier selection, equipment schedules and packaging weights, because those are where the measured figure moves. Assurance of any published report stays with an independent provider.

By the end of November 2026, test the group against the new CSRD thresholds at entity and group level for the last two financial years, record the result, and note which subsidiaries could be asked for value-chain data.

By December 2026, UK-listed companies should map their current climate disclosures to UK SRS S1 and S2 and decide which reliefs they will use for periods starting on 1 January 2027.

By January 2027, connect energy, fuel card and shipment records into one monthly dataset with source references, starting with the largest sites and freight lanes.

By February 2027, importers of CBAM goods should hold verified installation data or a documented default value for each 2026 entry, and compare the two where both exist.

By April 2027, ask the main carriers for shipment-level emissions on an ISO 14083 basis and reconcile them with the business's own shipment records and any emissions surcharges.

By June 2027, prepare a response in the format of the voluntary SME standard from measured data, ready for the customer, lender and tender requests that arrive regardless of scope.