External Reviewers of European Green Bonds

External reviewers provide an independent opinion on whether an issuer of European Green Bonds complies with the Taxonomy requirements of the European Green Bonds Regulation. ESMA will be the direct supervisor of external reviewers of European Green Bonds within the EU, under Regulation (EU) 2023/2631 (‘European Green Bonds Regulation’).

To issue a European Green Bond, an issuer must use an external reviewer:

  • before the issuance of a European Green Bond (‘pre-issuance review of European Green Bond factsheet') and;
  • after the full allocation of its proceeds ‘(post-issuance review of allocation report’).
Registration required from 21 June 2026.

ESMA is responsible for the registration and supervision of external reviewers.



The European Green Bonds Regulation was published in the Official Journal of the European Union on 30 November 2023.  

The Regulation entered into force on 21 December 2023 and will apply 12 months after, on 21 December 2024, with the exception of the derogations outlined in 72(3) and 72(4). 


Transitional regime

From 21 December 2024, a transitional regime will be in place. This means external reviewers can provide services after notifying ESMA and providing the registration information referred to in Article 23(1) of the Green Bond Regulation. External reviewers operating during the transition period should make their best efforts to comply with the requirements set out in Articles 24 to 38

After the 18 months deadline, on 21 June 2026, external reviewers shall provide services only after they have been registered by ESMA.

To register as an external reviewer, ESMA  will assess whether a firm meets the conditions set out in Article 23(1) of the Regulation on European Green Bonds based on the information provided by the applicant. 

ESMA is mandated to develop Regulatory Technical Standards (RTS) that will explain further the criteria used for assessing an application for registration by an external reviewer. ESMA will also produce Implementing Technical Standards (ITS) to outline the standard forms, templates and procedures for the submission of the information for registration. ESMA will consult on both the RTS and ITS. Further information on these consultations will be available on our website soon. 

To receive further information on the registration process, please contact CSC_ESG_GBS@esma.europa.eu.


Non-EU External reviewers

The Regulation includes a third-country regime for non-EU external reviewers of EU Green Bonds.

The equivalence regime applies to external reviewers established in a non-EU country whose legal and supervisory framework has been recognised as equivalent through a decision adopted by the European Commission.

In the absence of an equivalence decision, an external reviewer with a legal representative established in the European Union, may apply for recognition as long as they comply with the requirements of the EU GB. ESMA will draft RTS specifying the information and the form and content required for applications for recognition to ESMA.

The endorsement regime is available for external reviewers established in the EU for endorsement of the services provided by a third-country external reviewer, provided that it is able to demonstrate to ESMA on an ongoing basis that the provision of services fulfils requirements which are, at least, as stringent as the requirements of the European Green Bonds Regulation, that it has the necessary expertise to effectively monitor and manage the associated risks and that the services of the third-country external reviewer are used for objective reasons.