Independent Assurance built on the standards regulators already recognise.
SYNE provides independent third-party assurance over ESG, sustainability, carbon and climate-related disclosures - from a single GHG inventory to a full integrated sustainability report - conducted under ISAE 3000, ISAE 3410 and ISO 14064-3, with the same independence standards behind every SYNE Rating.
From a single emissions figure to a full sustainability report.
SYNE's Independent Assurance covers ESG and sustainability disclosures, carbon and decarbonisation reporting, climate assets, and non-CO2 super pollutants - built for anyone whose disclosures need to hold up to external scrutiny.
ESG & Sustainability Report Assurance
Limited and reasonable assurance over sustainability, integrated, and CSRD/ESRS-aligned reports.
GHG Inventory & Emissions Assurance
Independent assurance over Scope 1, 2 and 3 GHG inventories under ISO 14064-3 and ISAE 3410.
Carbon Credit & Climate Asset Verification
Validation and verification of carbon credits, removals and other climate assets against registry methodologies.
Super Pollutant & Non-CO2 GHG Assurance
Assurance over methane, HFCs, N2O and black carbon disclosures - gases with outsized short-term climate impact.
Net-Zero & Decarbonisation Target Assurance
Assurance over progress against SBTi-validated targets and transition plan milestones.
Regulatory & Cross-Border Assurance
Assurance support for CBAM embedded emissions filings, EU Taxonomy alignment, and SFDR disclosures.
Four service lines. One independence standard.
Every engagement sits under one of four service lines - ESG & Sustainability, Carbon & Decarbonisation, Climate Assets & Carbon Markets, and Super Pollutants & Non-CO2 GHGs - each conducted to the same evidentiary standard, regardless of which one applies.
ESG & Sustainability Assurance
Assurance over disclosures that sit outside the financial statements but carry the same scrutiny.
- Sustainability & Integrated Report Assurance (CSRD/ESRS, GRI, SASB)
- Non-Financial KPI Assurance
- Modern Slavery & Human Rights Statement Assurance
- SFDR & EU Taxonomy Alignment Assurance
Carbon & Decarbonisation Assurance
Assurance over a company's own emissions footprint and its path to reducing it.
- GHG Inventory Assurance (Scope 1, 2 & 3)
- Net-Zero & SBTi Target Progress Assurance
- Product Carbon Footprint (LCA) Assurance
- CBAM Embedded Emissions Verification
Climate Assets & Carbon Markets Assurance
Verification of the tradable instruments built on top of a claimed climate outcome.
- Carbon Credit Issuance Verification (VVB Role)
- Carbon Removal & Nature-Based Asset Verification
- Renewable Energy Certificate (REC) Assurance
- Green & Sustainability-Linked Bond KPI Assurance
Super Pollutants & Non-CO2 GHG Assurance
Assurance over gases with disproportionate short-term warming impact, often under-scrutinised relative to CO2.
- Methane Emissions Assurance (OGMP 2.0-Aligned)
- HFC & F-Gas Disclosure Assurance (Kigali Amendment)
- Black Carbon & Short-Lived Climate Pollutant Assurance
- N2O & Industrial Process Emissions Assurance
Not every disclosure needs - or can support - the same level of scrutiny.
SYNE offers three distinct forms of independent conclusion, each suited to a different type of disclosure and stage of data maturity.
Limited Assurance
A negative-form conclusion - "nothing has come to our attention to suggest the disclosure is materially misstated." Faster and less costly, and the common starting point for first-time CSRD/ESRS and GHG reporting.
Reasonable Assurance
A positive-form conclusion - "in our opinion, the disclosure is fairly stated." Comparable in rigor to a financial statement audit, and increasingly required for Scope 1 and 2 emissions under phased CSRD and SEC climate rules.
Validation & Verification
Used for carbon credits and climate assets - a pass/fail determination of whether a project or issuance complies with its chosen registry methodology, performed in SYNE's VVB (Validation/Verification Body) capacity.
Every opinion traces back to a published, external standard.
SYNE doesn't assure against an internal checklist - every engagement is scoped against a recognised assurance standard and the specific reporting framework or registry methodology the disclosure was prepared under.
Assurance standards
The professional standards that govern how an assurance engagement is planned, evidenced and concluded.
Reporting frameworks assured against
The disclosure frameworks a client's report or inventory has been prepared under.
Carbon market & climate asset standards
The registry and methodology standards climate assets are verified against.
Regulatory regimes supported
The regulatory filings and disclosure mandates SYNE's assurance opinions are built to support.
SYNE's assurance teams operate independently of SYNE's rating and advisory teams, with disclosed conflict-of-interest safeguards, so an assurance opinion is never influenced by a commercial rating or advisory relationship with the same client.
From engagement scoping to a signed opinion.
Every assurance engagement follows the same four stages, regardless of the disclosure type or assurance level involved.
Engagement Planning
Agree the disclosure, reporting period, assurance level and applicable standard before fieldwork begins.
Testing & Evidence Gathering
Sample testing, site visits, and data traceability checks appropriate to the assurance level agreed.
Independent Technical Review
Findings reviewed by an independent technical partner not involved in the fieldwork.
Assurance Report & Opinion
A signed assurance report and opinion issued, ready for inclusion in a regulatory filing or public disclosure.
Built for anyone whose disclosure needs to survive scrutiny.
An assurance opinion exists to answer one question for a third party: can this disclosure be relied upon?
Corporates & Sustainability Teams
Meet phased CSRD/ESRS assurance mandates, moving from limited to reasonable assurance over time.
Carbon Project Developers & Issuers
Secure independent validation and verification ahead of credit issuance under a chosen registry methodology.
Investors & Lenders
Rely on assured disclosures rather than self-reported figures when assessing counterparty ESG claims.
Boards & Audit Committees
Discharge oversight responsibilities with an independent opinion on sustainability and climate disclosures.
Governments & Regulators
Require assured disclosures as part of CBAM filings, national carbon pricing, and taxonomy alignment reporting.
Carbon Registries & Exchanges
Require independent verification from an accredited body before listing or issuing a climate asset.
A disclosure a company writes about itself is not the same as one a third party has tested.
Self-reported ESG and carbon figures are prepared by the same organisation whose performance they describe - with no independent check on data quality, calculation methodology, or scope completeness. Regulators, investors and carbon markets are converging on the same conclusion: material climate and sustainability disclosures need the same independent scrutiny as financial statements.
Why self-reported data isn't enough
An organisation marking its own homework has every incentive, even unintentionally, to present its performance in the best light.
What it means for regulated reporting
CSRD phases from limited toward reasonable assurance over time, and CBAM already requires verified embedded-emissions data at the border.
What it means for carbon markets
A carbon credit without independent verification against its registry methodology is a claim, not a tradable, defensible asset.
What assurance actually delivers
A signed, independent opinion that a specific disclosure - read as a whole - is free of material misstatement, at a defined level of confidence.
What separates a SYNE opinion from a self-declared checkmark.
Four principles run through every engagement, regardless of assurance level or disclosure type.
Structurally independent
Assurance engagements are conducted by teams separate from SYNE's rating and advisory functions, with disclosed conflict safeguards.
Built on global assurance standards
Every opinion is issued under ISAE 3000, ISAE 3410 or ISO 14064-3 - never an internally defined process.
Regulatory-grade independence
Operating under the same independence standards as every SYNE Rating, with methodology and safeguards published.
Same evidentiary bar, every engagement
A limited-assurance engagement and a reasonable-assurance engagement differ in scope, never in evidentiary rigor.
Assurance tests what you said. A rating judges how good it is.
An assurance opinion answers whether a specific, stated disclosure is materially accurate. A SYNE Rating goes further, independently judging the underlying performance itself.
An opinion on a statement, not a grade
Assurance concludes on whether a disclosure is free of material misstatement - it doesn't produce an AAA–D grade for the entity behind it.
A signed opinion & report
Engagements conclude with a formal assurance report and signed opinion, built for inclusion in a regulatory filing or annual report.
4–10 weeks, scoped to assurance level
Limited assurance engagements typically run 4–6 weeks; reasonable assurance and VVB verification engagements run 6–10 weeks.
Separate from SYNE's ratings
Assurance teams operate under a structural firewall from SYNE's rating analysts, even when both are engaged by the same client.
Feeds into MRV & data quality scores
An assured disclosure strengthens the data quality component of a related Carbon, ESG or Sustainability Rating.
Recognised across regulators & registries
Accepted by carbon registries, exchanges and regulators across our 71 licensed markets as independent third-party assurance.
Assurance delivered across 71 licensed countries.
SYNE's assurance teams are structured to meet local regulatory recognition requirements across every jurisdiction we're licensed in, from CSRD-scoped EU entities to CBAM-affected importers and registry-listed carbon projects worldwide.
View the full country list →Each mark represents active coverage in one jurisdiction
The ratings and services this assurance connects to.
Independent Assurance strengthens the data behind SYNE's rating products, and sits alongside the rest of SYNE's advisory services.
Get an assurance opinion regulators and investors can rely on.
Talk to our team about scoping a limited or reasonable assurance engagement, or a carbon credit verification.