EU Green Bond External Reviewers: What ESMA’s Register Means for Issuers and Reporting Teams

ByOfficer

Last updated: June 2026

If your treasury team is preparing a European Green Bond, the EU Green Bond external reviewers register is now a pre-pricing control. From 22 June 2026, a reviewer must have a valid ESMA-recognised status under the EuGB framework before it can provide external review services: Article 23 registration for EU-established reviewers, Article 39 third-country registration following an equivalence decision, Article 42 recognition, or Article 43 endorsement through an EU-registered reviewer. A pre-issuance opinion signed by a reviewer who is no longer permitted to provide the service is not a defect you want to discover after pricing. The label “European Green Bond” depends on that opinion existing and being valid.

ESMA published the register of external reviewers on 22 June 2026, the same date the transitional regime ended. The two events are linked. For the first 18 months that the Regulation applied, reviewers could operate on a notification basis. That soft-launch window has closed. The article walks through what the register changes for issuers and, more practically, for the reporting teams who own the factsheet, the allocation report, and the post-issuance review that the EU Green Bond designation is built on.

This is an EU-wide framework. There is no national-supervisor split here: ESMA is the direct and exclusive supervisor of external reviewers across the Union, so the same register and the same rules apply whether the issuer is in Luxembourg, Germany, Ireland, or anywhere else in the single market.

Related reading: our guide to CSRD sustainability reporting, which sits alongside the green bond framework in the EU sustainable-finance stack.

What the EU Green Bond Regulation actually requires

The framework is Regulation (EU) 2023/2631 on European Green Bonds and optional disclosures for bonds marketed as environmentally sustainable and for sustainability-linked bonds. It was adopted on 22 November 2023, published in the Official Journal on 30 November 2023, entered into force on 20 December 2023, and has applied since 21 December 2024. The “EuGB” designation is voluntary, but once an issuer uses it, the Regulation’s obligations are not optional.

The core promise of the label is allocation. Article 4 requires that the proceeds of a European Green Bond be allocated in full, before the bond matures, to activities aligned with the EU Taxonomy requirements. That is the substantive test underneath the marketing word “green,” and it is the same taxonomy logic ESMA has been pressing on in adjacent files such as its supervisory work on MiFID II sustainability preferences. Everything the external reviewer checks, and everything the reporting team produces afterwards, exists to evidence that allocation.

The Regulation builds three reporting artefacts around that promise. Before issuance, the issuer completes a European Green Bond factsheet using the template in Annex I (Article 10). After issuance, the issuer produces an allocation report for every 12-month period until the proceeds are fully allocated (Article 11). Once allocation is complete, and at least once during the bond’s life, the issuer produces an impact report using the Annex III template (Article 12). The external reviewer’s signature attaches to the first two of those.

Where the EU Green Bond external reviewer fits: two mandatory reviews, one optional

The Regulation requires a pre-issuance review before issuance and a post-issuance review of the allocation report drawn up after full allocation. The review scope is wider where the issuer uses the portfolio approach: every allocation report is subject to post-issuance review unless the Article 11(6) no-change exception applies. Where a CapEx plan is used, Article 7 also requires an external reviewer assessment within 60 days of the CapEx-plan deadline.

The pre-issuance review comes first. Under Article 10, before the bond is issued the issuer must obtain a pre-issuance review with a positive opinion from an external reviewer. The reviewer assesses whether the factsheet has been completed in accordance with Articles 4 to 8, which is to say whether the use-of-proceeds and taxonomy-alignment claims hold up on paper. Without that positive opinion, the bond cannot carry the European Green Bond designation.

The post-issuance review comes later and is the one teams underestimate. Article 11 requires the issuer to obtain a post-issuance review by an external reviewer of the allocation report drawn up after the full allocation of proceeds. The Regulation makes it mandatory. It is also a separate engagement from the pre-issuance review, with its own opinion and its own lead time.

Only the impact report sits outside the mandatory perimeter. Under Article 12, an external review of the impact report is available but optional. Teams that assume “the green bond needs a review” sometimes spend budget reviewing the impact report while treating the post-issuance allocation review as discretionary. That gets the priority backwards. The allocation-report review is the one the Regulation requires; the impact-report review is the one you may choose.

The 270-day deadline and the reviewer’s 90-day window

Article 11 sets the cadence that the reporting calendar has to absorb. An allocation report covers every 12-month period until full allocation of proceeds and, where applicable, until completion of the CapEx plan. The issuer must ensure that the annual allocation report and any required post-issuance review are made public within 270 days of the end of the relevant 12-month period. That is the hard date. Miss it and the issuer has failed an explicit obligation tied to the designation.

What makes 270 days less generous than it sounds is the review carved out of it. The Regulation provides that, where the allocation report is subject to a post-issuance review, the external reviewer must be given at least 90 days to review it. The 90 days sit inside the 270, not on top of them. A reporting team that finalises its allocation data on day 200 has left the reviewer short of the time the Regulation guarantees them, and the reviewer is entitled to it.

The practical consequence is a backward-planned timeline. If the post-issuance review is the one that closes out full allocation, the internal data has to be reconciled, the report drafted, and the reviewer engaged well before the 270-day wall. Treating the reviewer’s 90 days as the last thing that happens before publication, rather than a fixed block reserved early, is how teams end up requesting an opinion they cannot lawfully compress.

One more publication point sits in Article 15. Factsheets and pre-issuance reviews go on the issuer’s website before issuance; allocation reports and post-issuance reviews go up without undue delay; and the issuer notifies ESMA within 30 days of publication. Website publication is itself a regulatory obligation that teams sometimes treat as optional housekeeping.

What the register changes: the reviewer must now be authorised

Until 22 June 2026, an external reviewer could provide services on a transitional basis. Articles 69 and 70 of the Regulation let reviewers operate during the transition period if they notified ESMA and made best efforts to comply, with third-country reviewers required to have a legal representative established in the Union. That window covered the first 18 months of application, from 21 December 2024 to 21 June 2026.

That regime has ended. From 22 June 2026, external reviewers must hold a current valid ESMA status under the registration framework in the Regulation. ESMA has exclusive responsibility for registration and supervision of external reviewers, can require information necessary for its supervisory tasks, and can impose fines or periodic penalty payments, mirroring the gatekeeper role it plays over ratings-adjacent providers in workstreams like its call for evidence on private credit ratings. The register ESMA published lists the firms that have completed full registration, alongside the historical record of who operated under the transitional notification and for which periods.

As of the register’s publication on 22 June 2026, five external reviewers were registered: Moody’s France SAS, Moody’s Deutschland GmbH, Sustainable Fitch Ireland Limited, S&P Global Ratings Europe Limited, and ISS-Corporate AB. That is a deliberately short list, and it is the practical heart of this change. A reviewer that operated under the transitional notification but has not appeared on the registered list may no longer provide external review services under the Regulation after 21 June 2026.

The issuer’s actual exposure: check the register before you rely on the opinion

The most concrete error available here is relying on a reviewer who is no longer permitted to act. It is not a hypothetical. A reviewer that operated during the transition has every reason to look like a valid counterparty, with prior opinions on file and an existing relationship. The transition status does not survive 21 June 2026, and the European Green Bond designation rests on the opinion being given by an authorised reviewer.

The check is mechanical, which is the point. Before commissioning a pre-issuance review for any bond intended to carry the designation, confirm the reviewer’s name is on ESMA’s current register. Before relying on a post-issuance review to close out full allocation, do the same. The register is maintained and updated by ESMA, so the check is a live one rather than a one-time confirmation at the start of a relationship.

The register records prior transitional activity, but the authority to provide reviews going forward depends on a current valid ESMA status: EU registration, third-country registration under an equivalence route, recognition, or endorsement through an EU-registered reviewer. Historical entries confirm when a firm was active during the transition; they do not extend that permission beyond 21 June 2026.

How a firm becomes a registered external reviewer

For completeness, and because issuers sometimes want to understand whether a preferred reviewer is likely to make the list, the registration route runs through ESMA directly. Registration is not automatic: ESMA assesses senior-management suitability, analytical capacity, governance, internal controls, methodologies and conflicts-management arrangements before registration or recognition can take effect.

For an EU-established reviewer applying for Article 23 registration, the fee is EUR 40,000 under Article 1(1) of Commission Delegated Regulation (EU) 2025/755. The same Regulation sets a EUR 10,000 fee for Article 39 third-country registration, a EUR 40,000 fee for Article 42 recognition, and a EUR 20,000 fee for Article 43 endorsement authorisation. Applications are submitted to ESMA at extreviewreg@esma.europa.eu, and ESMA acknowledges receipt within one working day.

The trap on the application side is treating registration as a formality that any prior transitional reviewer will clear automatically. Notification under the old regime and registration under the new one are different tests. A firm could have notified, operated, and then not appeared on the registered list. ESMA encourages firms to apply as early as possible using a completeness template, which matters for issuers because the supply of registered reviewers is what determines whether the issuer has a real choice of counterparty.

Third-country reviewers: three routes, not one

Plenty of green-bond review work has historically been done by firms headquartered outside the EU. The Regulation does not shut them out, but it channels them through one of three defined routes, and the routes are not interchangeable.

The first is equivalence, which depends on the European Commission recognising a non-EU country’s framework as equivalent. The second is recognition, available to a non-EU reviewer that has an EU legal representative and complies with the Regulation’s requirements. The third is endorsement, under which an EU-established external reviewer endorses a third-country firm’s services after satisfying itself that the third-country requirements are at least as stringent as the Regulation. The Commission has filled in part of the detail for third-country applications through Commission Delegated Regulation (EU) 2026/544 of 12 March 2026 (C/2026/80; OJ L, 2026/544, 17 June 2026), which specifies the information, form, and content for those applications.

For an issuer, the relevant misconception is that a globally recognised reviewer brand automatically qualifies in the EU. A non-EU entity’s standing in another market does not create EuGB authority on its own. Whether a particular non-EU reviewer can sign a valid opinion depends on which of the three routes it has used and whether that route is complete, which again comes back to the register.

Where this sits in the wider sustainable-finance reporting load

The external reviewer register is one moving part in a sustainable-finance reporting stack that reporting teams are already carrying. The taxonomy-alignment test under Article 4 of the Green Bond Regulation draws on the same EU Taxonomy that feeds Article 8 Taxonomy disclosures and the broader corporate sustainability reporting framework. Teams that have built taxonomy-eligibility and alignment data for those disclosures are not starting from zero on the green bond factsheet, though the use-of-proceeds framing is bond-specific.

The market context is modest in scale but real. By March 2026 there had been more than 30 European Green Bond issuances with a combined volume of around EUR 30 billion, with issuers spanning utilities, banks, municipalities, and at least one Member State sovereign. The framework is no longer theoretical, and the move from notification to registration is the signal that the EU is treating the external review function as a supervised gatekeeper rather than a market convenience. For reporting teams, the practical read-across is that other parts of the disclosure chain, from the CSRD omnibus changes to taxonomy-aligned data, sit close enough that the same data owners are often involved.

Frequently Asked Questions

When did ESMA’s register of external reviewers go live, and what happened to the transitional regime?

ESMA published the register on 22 June 2026. The transitional regime under Articles 69 and 70 of Regulation (EU) 2023/2631, which let reviewers operate on a notification basis during the first 18 months of application, ended at the same time. From 22 June 2026, external reviewers must be formally registered with ESMA. The transitional period ran from the Regulation’s date of application on 21 December 2024 to 21 June 2026.

Which firms are on the register?

As of publication on 22 June 2026, five external reviewers were registered: Moody’s France SAS, Moody’s Deutschland GmbH, Sustainable Fitch Ireland Limited, S&P Global Ratings Europe Limited, and ISS-Corporate AB. ESMA maintains and updates the register, so the current list should be checked directly before relying on any reviewer.

Does an issuer need an external review at all, or is it optional?

For a bond carrying the European Green Bond designation, a pre-issuance review of the factsheet with a positive opinion under Article 10 is mandatory, and a post-issuance review of the allocation report drawn up after full allocation is mandatory under Article 11. If the issuer uses the portfolio approach, each allocation report is subject to post-issuance review unless the Article 11(6) no-change exception applies. An external review of the impact report under Article 12 is optional.

How long does the issuer have to publish an allocation report?

Under Article 11, the issuer must publish each allocation report within 270 days of the end of the relevant 12-month period. Where the report is subject to a post-issuance review, the external reviewer must be given at least 90 days within that window to carry out the review, so the internal data and draft need to be ready well before the 270-day deadline.

Can a non-EU external reviewer sign a valid EuGB opinion?

Potentially, but only through one of three defined routes: equivalence based on a Commission decision recognising the third country’s framework, recognition where the non-EU reviewer has an EU legal representative and meets the Regulation’s requirements, or endorsement by an EU-established reviewer of a third-country firm whose requirements are at least as stringent as the Regulation. Commission Delegated Regulation (EU) 2026/544 of 12 March 2026 (C/2026/80; OJ L, 2026/544, 17 June 2026) specifies the information and form for third-country applications. A reviewer’s standing in another market does not by itself confer EuGB authority.

What does it cost a firm to register as an external reviewer?

For an EU-established reviewer applying for Article 23 registration, the fee is EUR 40,000 under Article 1(1) of Commission Delegated Regulation (EU) 2025/755. The same Regulation sets a EUR 10,000 fee for Article 39 third-country registration, a EUR 40,000 fee for Article 42 recognition, and a EUR 20,000 fee for Article 43 endorsement authorisation. Applications are submitted to ESMA at extreviewreg@esma.europa.eu, and ESMA acknowledges receipt within one working day.

What happens to opinions issued by a reviewer that operated under the transition but is not registered?

The register records prior transitional activity and the periods during which firms were active, but the authority to provide external reviews going forward depends on current registration. A firm that operated under the transitional notification and has not appeared on the registered list may no longer provide external review services under the Regulation after 21 June 2026. Past activity does not create ongoing permission.

Related Articles

Key Takeaways

  • ESMA published the register of external reviewers under Regulation (EU) 2023/2631 on 22 June 2026; the transitional notification regime under Articles 69 and 70 ended at the same time.
  • From 22 June 2026, a reviewer must hold a current valid ESMA status (EU registration, third-country registration, recognition, or endorsement) before it can provide external review services under the EU Green Bond Regulation. Five firms were registered at launch.
  • A European Green Bond requires a pre-issuance review of the factsheet under Article 10 and a post-issuance review of the allocation report after full allocation under Article 11. If the issuer uses the portfolio approach, each allocation report is subject to post-issuance review unless the Article 11(6) no-change exception applies. The impact-report review under Article 12 is optional.
  • Allocation reports must be published within 270 days of the end of each 12-month period, with at least 90 days reserved inside that window for the reviewer.
  • Before relying on any opinion, confirm the reviewer is on ESMA’s current register; transitional activity is recorded but does not confer ongoing permission.
  • Non-EU reviewers must use one of three routes, equivalence, recognition, or endorsement, with third-country application detail in Commission Delegated Regulation (EU) 2026/544 of 12 March 2026 (C/2026/80; OJ L, 2026/544, 17 June 2026).
  • Registration fees under Commission Delegated Regulation (EU) 2025/755: EUR 40,000 for Article 23 EU registration, EUR 10,000 for Article 39 third-country registration, EUR 40,000 for Article 42 recognition, EUR 20,000 for Article 43 endorsement authorisation.

Sources and References

What to put on your pre-pricing checklist

The single action that matters most is the cheapest one: before any European Green Bond goes to market, open ESMA’s register and confirm the chosen reviewer is on it with a current valid status, then keep the post-issuance review timeline honest by reserving the reviewer’s 90 days inside the 270-day window rather than at the end of it. The designation is only as sound as the opinion behind it, and after 22 June 2026 the opinion is only as sound as the reviewer’s registration. Build the register check into the pre-pricing checklist and the post-issuance reporting calendar, and the rest of the framework becomes a question of producing the factsheet, the allocation report, and the impact report on time.

Disclaimer: The information on RegReportingDesk.com is for educational and informational purposes only. It does not constitute legal, regulatory, tax, or compliance advice. Always consult your compliance officer, legal counsel, or the relevant supervisory authority for guidance specific to your institution.

Similar Posts