Guidelines for External Reviews
External Review Service Mapping
Guidelines for External Reviews

These Guidelines for External Reviewers provide voluntary guidance relating to professional and ethical standards for external reviewers, as well as to the organisation, content and disclosure for their reports. They have been developed as a common undertaking between the Executive Committee of the Principles and the Advisory Council in consultation with a group of leading external reviewers, with the support of the ICMA Secretariat with the common objective to promote best practice in the provision of external review services for green, social, sustainability and sustainability-linked bonds.

The guidelines complement the Green Bond Principles, the Social Bond Principles, the Sustainability Bond Guidelines and the Sustainability-Linked Bond Principles, and reference other existing relevant guidance.

The 2022 version provides additional guidance especially for Second Party Opinions or verification which are considering climate transition in connection with any Use of Proceeds or Sustainability-Linked Bond issuance, in accordance with the four key elements of the Climate Transition Finance Handbook.

The Principles recommend that the external review reports be made publicly available on the bond issuer’s website and/or through any other accessible communication channel as appropriate, before or at the time of the issuance. Providers are also encouraged to complete the External Review Form for Use of Proceeds Bonds or the External Review form for Sustainability-Linked Bonds. These forms provide information on the role of the external reviewer when assessing the issuer’s sustainability framework, the scope of the review and the related methodology. This helps inform the market participants on a standardised format. Completed forms can be made available on the Sustainable bond issuers database.


The external reviewers listed below have contributed to, and confirmed that they will voluntarily align with the Guidelines consistent with any regulatory obligations*:


*Please note that ICMA has not investigated or confirmed compliance by the external reviewers with the Guidelines, nor does it recommend, endorse or make any representations regarding the external reviewers listed above.



Translations of the Guidelines for External Reviewers


Please note that the following translations are related to the 2018 edition. They will be updated with the 2021 changes progressively, therefore the edition that each translation currently refers to is indicated below.

External Review Service Mapping

Overview of the External Review Service Mapping

The purpose of the mapping of external reviews is to provide market participants with clear information on the range of services offered as well as the context and content of the final external review report. The Overview is supplied by the templates that external reviewers have provided (see below).

This Excel spreadsheet is divided into 3 tabs: (1) External review services – (2) Timing and coverage – (3) Geographic scope and languages.

To have access to an individual template, you can click on the name of the related provider (on the 1st tab of the Overview).

Download Overview of the External Review Service Mapping


Template for External Reviews

The External Review Service Mapping Template is an excel form where external reviewers are invited to voluntarily provide information about the different external review services they provide for Use of Proceeds bonds and/or Sustainability-Linked bonds.

The Executive Committee of the Principles encourages external reviewers to voluntarily fill in this template in order to promote transparency and disclosure and support market efficiency.

Questions related to the template may be addressed to the Secretariat of the Principles at sustainabilitybonds@icmagroup.org.


The Overview currently provides information on the following reviewers:




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