FRC takes steps to support quality and consistency in the assurance of sustainability reporting
News types: Codes and Standards Announcements
Published: 12 November 2025
The Financial Reporting Council (FRC) has today issued International Standard on Sustainability Assurance (UK) 5000, “General Requirements for Sustainability Assurance Engagements”, which provides UK companies, investors and assurance providers with a consistent, internationally aligned assurance standards for voluntary use in sustainability assurance engagements.
ISSA (UK) 5000 is a UK version of the global benchmark standard for sustainability assurance, developed by the International Auditing and Assurance Standards Board (IAASB). Its introduction for use in the UK demonstrates the FRC’s continued support for globally aligned assurance standards that underpin quality assurance engagements. The Standard provides comprehensive requirements for conducting sustainability assurance engagements, applicable to both limited and reasonable assurance, and is designed to be profession-agnostic.
The UK Standard is intended for voluntary use by UK assurance providers and aligns with the international standard. By assuring the credibility of UK sustainability reporting, ISSA (UK) 5000 will support more informed investment decisions and enhance the attractiveness of the UK as a leading destination for sustainable finance.
The FRC remains committed to globally aligned frameworks that promote streamlined reporting, consistent audit and assurance standards, and reliable information for investors and other users of reporting.
Mark Babington, Executive Director of Regulatory Standards at the FRC“The release of ISSA (UK) 5000 marks a significant step in establishing a consistent framework for sustainability assurance in the UK. It reflects our commitment to internationally aligned standards and supports the growing demand for high-quality, assured sustainability information which users can trust.
By underpinning investor confidence in sustainability disclosures, this standard will help UK companies access capital more efficiently and contribute to long-term economic growth.”
The FRC received strong support across stakeholder groups—including firms, professional bodies, investors, and companies—for issuing the standard on a voluntary basis.