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Sustainability assurance

With the increasing global demand for corporate reporting and disclosure on sustainability, ESG and climate, the focus on assurance over sustainability-related information has never been greater. Find information, insights and resources below.

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Mark Babington, Board Member of International Ethics Standards Board for Accountants (IESBA), in conversation with ICAEW’s Director of Trust and Ethics, Laura Hough.
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Exclusive
Audit & Beyond

Building trust and readiness for sustainability assurance

As sustainability considerations become embedded into boardroom decision making, and more sustainability-related information is disclosed for external decision-making, a fundamental question remains: how can this information be trusted?
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ICAEW Sustainability Assurance Certificate

Access applied learning structured around the assurance engagement process, complete with realistic case studies. This certificate equips you to provide trusted assurance in sustainability reporting.
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Exclusive
Audit and Beyond

Engaging with sustainability assurance

Explore key insights on the emerging global sustainability assurance framework, with practical pointers from audit and assurance professionals in practice and standard setting.
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Exclusive
Audit and Beyond

Why ethics and sustainability go hand in hand

IESBA Board Member Mark Babington talks to ICAEW about the relevance and importance of ethics when it comes to sustainability reporting and assurance.
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Resources

Climate assurance

A suite of resources to enable boards and audit committees to evaluate the need for assurance over climate-related activities.
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Sustainability assurance: embracing the future Hear from our new CEO Alan Vallance on the critical role of sustainability assurance in today's business landscape.

Latest news and insights

Exclusive Building trust and readiness for sustainability assurance
  • Article
  • 21 May 2026
As sustainability considerations become embedded into boardroom decision making, and more sustainability-related information is disclosed for external decision-making, a fundamental question remains: how can this information be trusted?
Are you ready to offer sustainability assurance?
  • Article
  • 05 Feb 2026
As two landmark standards aim to advance trust and transparency in sustainability information, a new ICAEW course will help firms provide high-quality assurance services in the field.
UK voluntary sustainability assurance oversight regime announced
  • Article
  • 03 Feb 2026
The UK government has outlined its position on the voluntary sustainability oversight regime, as the Financial Conduct Authority (FCA) opens its consultation on sustainability disclosures
2026: Sustainability reporting and assurance
  • Article
  • 01 Jan 2026
In 2026, accountants will play a critical role in preparing companies to disclose and assure sustainability information, says Ravi Abeywardana, Director of Sustainability Reporting and Assurance at ICAEW.
Executing a sustainability assurance engagement
  • Article
  • 28 Aug 2025
As the focus on sustainability reporting and assurance intensifies, ICAEW is offering practical support to members on how to plan and execute a sustainability assurance engagement.
Government launches UK sustainability assurance regime consultation
  • Article
  • 01 Jul 2025
Proposals include a new category of ‘sustainability assurance provider’ qualified to provide third-party assurance over sustainability-related financial disclosures, and a voluntary registration regime for sustainability assurance.
FRC consults on UK sustainability assurance standard
  • Article
  • 09 Jun 2025
Regulator proposes introduction of a UK version of International Standard on Sustainability Assurance 5000 for periods beginning on or after 15 December 2026.
EU Parliament votes through CSRD and CSDDD delay
  • Article
  • 04 Apr 2025
The vote confirms the postponement of the Corporate Sustainability Reporting Directive and the Corporate Sustainability Due Diligence Directive by two years and one year respectively.

IAASB international assurance standard

Exclusive ISSA 5000: IAASB sustainability assurance standard
  • Article
Auditors and other professional assurance practitioners will want to become familiar with the new general-purpose standard for sustainability assurance.
Sustainability assurance standard on track for September delivery
  • Article
IAASB Vice-Chair gives progress report on ISSA 5000, an ambitious project to develop a globally-accepted overarching standard for sustainability assurance.
Consultation opens on global sustainability assurance standard
  • Article
The International Auditing and Assurance Standards Board (IAASB) is calling on anyone involved with preparing, using and regulating sustainability reports to feedback on its proposed International Standard on Sustainability Assurance – ISSA 5000.
ICAEW REP 114/23 ISSA 5000
  • Representation
  • PDF (393kb)
A representation dated 1 December 2023 to a consultation published by IAASB in August 2023.

Sustainability reporting standard setting

IFRS Sustainability Disclosure Standards
  • Helpsheets and support
On this page, the Corporate Reporting Faculty provides an introduction to the work of the International Sustainability Standards Board (ISSB) and its IFRS Sustainability Disclosure Standards.
European Sustainability Reporting and Assurance
  • Helpsheets and support
An overview of the EU legal framework for sustainability reporting, under the Corporate Sustainability Reporting Directive (CSRD).
CSRD scope and timing
  • Helpsheets and support
The CSRD applies to a broad range of companies. This page covers the scope, timing and exemptions for applying CSRD.
SEC standardises climate-related disclosures for investors
  • Article
The US Securities and Exchange Commission has clarified its climate-related disclosures rules after a lengthy deliberation period.

Helpsheets and guidance

Exclusive Global sustainability reporting and assurance requirements: your questions answered
  • Webinar
We explore current and future sustainability reporting and assurance requirements and put your questions to our expert panel.
Introduction to CSRD and SEC Climate Reporting & Assurance requirements
  • Webinar
An Overview of Corporate Sustainability Reporting Directive and SEC Climate disclosures.
What is assurance?
  • Helpsheets and support
Discover what assurance means, what can trigger the need for assurance, what an assurance engagement is and what assurance mapping is.
Limited assurance vs reasonable assurance
  • Article
Where the client and the practitioner establish that an assurance service is being sought, ISAE 3000 (Revised) provides two options; reasonable and limited assurance.
Practical help and tools for organisations procuring assurance
  • Article
On this page we provide information for the ‘buyer’, i.e. organisations that procure assurance services.
Assurance mapping
  • Helpsheets and support
Assurance maps can be a powerful tool providing great insights for boards, senior management and audit committees. Here the Audit and Assurance Faculty explores the concept of assurance maps and the benefits to various stakeholders.
Buyer’s guide to assurance on non-financial information
  • Helpsheets and support
What is assurance? How does it work and why might it be useful to users of non-financial information? This ‘Buyer's Guide to Assurance on non-financial information’, written collaboratively between ICAEW’s Audit and Assurance Faculty and the World Business Council for Sustainable Development , addresses these questions to bring much needed clarity on what is often perceived as a confusing topic.
The nine stages of an assurance engagement
  • Hub page
Assurance engagements can be typically broken up into nine stages. Not all stages will be clearly separated and identifiable in every engagement. Some stages, such as the engagement letter, may not be required during internal assurance, while others, such as the problem-solving phase, may not be necessary in some external engagements.

Connecting sustainability and finance

Accountants must take the lead on joining the dots between sustainability and finance information, performance and disclosures to ensure organisations are able to make the transformative changes needed

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Further resources

Resources
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Non-financial reporting

Find a range of resources on non-financial reporting matters including the strategic report, energy and carbon reporting, and TCFD disclosures.

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Hub
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ICAEW's Sustainability hub

Sustainability describes a world of thriving economies and just societies based on what nature can afford; finance professionals all have a role to play if sustainability goals are to be met.

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Sustainability and Climate Change

Inspiration, insights and collective ambition for professionals delivering on sustainability and acting on climate change.

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