The importance of the assurance of sustainability reports has
been recognized by GRI since its formal launch in 2002. In the
G4 Guidelines, GRI recommends the use of external assurance
for sustainability reports, but does not require it to prepare a
report ‘in accordance’ with the G4 Guidelines.
As one can find on page 51 of the G4 Guidelines –
Implementation Manual:
“GRI recommends the use of external assurance for sustainability
reports in addition to any internal resources, but does not require it.
GRI uses the term ‘external assurance’ to refer to activities designed
to result in published conclusions on the quality of the report
and the information (whether it be qualitative or quantitative)
contained within it. External assurance may also refer to activities
designed to result in published conclusions on systems or processes
(such as the process for defining report content, including
the application of the Materiality Principle or the stakeholder
engagement process). This is different from activities designed
to assess or validate the quality or level of performance of an
organization, such as issuing performance certifications or
compliance assessments.
A variety of approaches are currently used by report preparers to
implement external assurance, including the use of professional
assurance providers, or other external groups or individuals.
Regardless of the specific approach, external assurance should
be conducted by competent groups or individuals external to the
organization who follow professional standards for assurance, or
who apply systematic, documented, and evidence-based processes
(‘assurance providers’).
Overall, for external assurance of reports using the Guidelines, it is
important that the assurance providers:
• Are independent from the organization and therefore able
to reach and publish an objective and impartial opinion or
conclusions on the report
• Are demonstrably competent in both the subject matter and
assurance practices
• Apply quality control procedures to the assurance engagement
• Conduct the engagement in a manner that is systematic,
documented, evidence-based, and characterized by defined
procedures
• Assess whether the report provides a reasonable and balanced
presentation of performance, taking into consideration the
veracity of data in the report as well as the overall selection of
content
• Assess the extent to which the report preparer has applied the
Guidelines in the course of reaching its conclusions
• Issue a written report that is publicly available and includes an
opinion or set of conclusions, a description of the responsibilities
of the report preparer and the assurance provider, and a
summary of the work performed to explain the nature of the
assurance conveyed by the assurance report
An organization may have systems of internal controls in place
and, in some jurisdictions, corporate governance codes may
require directors to inquire, and then, if satisfied, to confirm in the
annual report the adequacy of the organization’s internal controls.
Organizations may also establish and maintain an internal audit
function, as part of their processes for risk management and for
managing and reporting information.
These internal systems are also important to the overall integrity
and credibility of a report.
An organization may convene a stakeholder panel to review its
overall approach to sustainability reporting or provide advice on
the content of its sustainability report.”
External assurance is covered in three sections of the G4
Guidelines:
• ‘In accordance’ criteria options (see p. 11 in Reporting
Principles and Standard Disclosures) – requests a statement
of the organization’s ‘in accordance’ criteria option, together
with an external assurance statement, if the report or parts of
it has been externally assured
• G4-33 (see p. 36 in Reporting Principles and Standard
Disclosures and p. 51 in Implementation Manual) – requests
information about policy and current practice regarding
seeking external assurance, among other points
• GRI Content Index (see p. 31 in Reporting Principles and
Standard Disclosures and p. 46 in Implementation Manual) –
requests signaling if a disclosure has been externally assured