TLDR: Voluntary reporting ended the obligation while the scrutiny stayed. The companies that verify their emissions data now keep the buyers, banks, and capital that still check.
Scrutiny outlived the deadline
The European Union’s Omnibus package raised the Corporate Sustainability Reporting Directive’s threshold (CSRD) to firms above 1,000 employees and €450 million in revenue, which takes roughly 80 per cent of previously covered companies out of mandatory scope. Switzerland is moving the same way: its proposed reporting and due-diligence law would bind only about 100 of the country’s largest companies, those above 1,000 employees and CHF 450 million (≈ €488 million).
When a fixed obligation vanishes, status quo bias and loss aversion (the asymmetry Daniel Kahneman and Amos Tversky first measured, and that Richard Thaler carried into policy) pull teams toward inaction. Many sustainability leads read a removed deadline as removed risk, and quietly stood down.
That read is expensive. Procurement teams still send emissions questionnaires. Lenders still price climate exposure into credit. Outside checking is already the norm: 73 per cent of large G20 companies obtained third-party assurance on sustainability data in 2023, up from 51 per cent in 2019, most of it limited assurance. The EU’s Carbon Border Adjustment Mechanism (CBAM) continues to require embedded-emissions data on imports of carbon-intensive goods such as steel, cement, and aluminium. And EFRAG’s Voluntary Standard for small and medium-sized enterprises (VSME) exists precisely because in-scope giants keep pushing data requests down their value chains. The mandate narrowed; the demand for credible numbers widened.
So the question has shifted from “must we report?” to “would our numbers hold up when someone outside the company checks them?” The five questions below answer that. Score yourself one point for each clear “yes.”
What “verifiable” actually means
Verifiable carbon data clears a measurement, reporting, and verification (MRV) bar: every figure traces to a source, any competent person reproduces it from the same method, and an outside reviewer follows the trail independently. The discipline spans the three accounting layers: Scope 1 (direct emissions a company controls), Scope 2 (purchased energy), and Scope 3 (the value chain, usually the largest and the weakest).
Most internal numbers clear the first layer and stumble on the rest. The five questions locate exactly where.
Specialist platforms now operationalise this work. Persefoni structures Scope 1 to 3 data to the Greenhouse Gas (GHG) Protocol methodology, Sweep automates Scope 1, 2, and 3 calculations with localised emission factors and supply-chain mapping, and Watershed folds carbon, water, and waste accounting into one reduction plan. Tooling accelerates the maths, and the discipline behind the five questions still decides whether the output survives review.
The five questions
1. Can you trace every reported number to a source document?
A verifiable figure points back to a meter reading, an invoice, a fuel log, or a supplier record. A figure that survives only as a summary cell, with the source document long gone, is an estimate.
2. Would two people reach the same figure from your method?
Reproducibility is the heart of verification. When the calculation rests on undocumented judgement calls (which emission factor, which boundary, which year), two analysts produce two answers, and an auditor rejects both.
3. Is your Scope 3 evidenced or assumed?
Scope 3 carries the most weight and the least rigour. Industry-average factors applied to spend data produce a plausible figure and little proof. Supplier-specific data, even partial, marks the line between a defensible footprint and a placeholder.
4. Does one person hold the whole system in their head?
Tribal knowledge is a single point of failure. When the method, the spreadsheet, and the assumptions live with one employee, the data set leaves the moment they do, and the company loses its ability to defend last year’s claims.
5. Could you hand an auditor the trail today, straight from your records?
Assurance turns on documentation that already exists. A company that needs three weeks to reconstruct its figures is still at the reporting stage, and that gap surfaces under any serious external review.
What to do with your score
A score of 4 or 5 signals data ready for assurance, lender scrutiny, and buyer questionnaires. A 2 or 3 signals a footprint that works in a slide and fails in an audit. Below 2, the numbers are a liability waiting for the first person who checks.
The next move depends on where a company sits. Large, still-in-scope firms should close the Scope 3 evidence gap first, because that is where assurance providers concentrate and where credit teams probe. Suppliers inside a larger company’s value chain should adopt the VSME structure now, so a single verified data set answers every customer questionnaire and replaces the per-buyer spreadsheet scramble. Investors and grant-makers should treat the five questions as diligence: a portfolio company that fails them is reporting impact it has yet to prove.
FAQ
Is carbon reporting still mandatory in Europe and Switzerland?
For most companies, the mandate has lifted. The EU’s Omnibus package and Switzerland’s proposed law confine required reporting to the largest firms. The data requests from buyers, banks, and the Carbon Border Adjustment Mechanism continue regardless.
What is the difference between reporting and verification?
Reporting states a number. Verification proves it through source documents, a reproducible method, and a trail an independent reviewer can follow.
Why does Scope 3 fail verification most often?
Scope 3 covers value-chain emissions that sit outside a company’s direct control. Teams estimate it from spend and industry averages, so the figure becomes the hardest to defend.
References
- Clark Hill. ESG & Sustainability in 2026: Twists, Turns, and Trends. https://www.clarkhill.com/news-events/news/esg-sustainability-in-2026-twists-turns-and-trends/
- ESG Today. Switzerland Proposes New Sustainability Reporting, Due Diligence Law. https://www.esgtoday.com/switzerland-proposes-new-sustainability-reporting-due-diligence-law/
- EFRAG. SMEs and Sustainability Reporting (VSME). https://www.efrag.org/en/smes-and-sustainability-reporting
- Mezyan. Sustainability Reporting Just Went Optional for 80% of Companies, and the Winners Are Reinvesting. https://mezyan.ch/sustainability-reporting-optional-innovation-advantage/
- IFAC, AICPA & CIMA. More Global Companies Seek Assurance on Sustainability Reporting (2025 study). https://www.ifac.org/news-events/2025-05/more-global-companies-seek-assurance-sustainability-reporting-study-ifac-aicpa-cima-shows
- Persefoni. Carbon Accounting and Sustainability Management Platform. https://www.persefoni.com/
- Sweep. Carbon and Sustainability Data Management. https://www.sweep.net/
