Insider lists after the EU Listing Act: what EU and UK-listed companies need to know

The EU Listing Act (Regulation (EU) 2024/2809) introduced a revised insider list format for EU-listed companies, which took effect on 5 July 2026.

For UK-listed companies, there is a straightforward question: do these changes apply to you? The short answer is no: UK MAR has not changed.

The detail matters, because this is the first significant divergence between EU MAR and UK MAR since the UK onshored the regulation on 31 December 2020.

TL;DR

UK MAR is unchanged. None of the EU Listing Act changes apply to UK-only listed companies.

EU insider list formats are simplified from 5 July 2026.

Dual-listed issuers now operate under two separate regimes with different insider list requirements.

The FCA continues to expect UK issuers to produce insider lists promptly on request, typically within two days.

What has changed in the EU?

Insider list formats simplified

ESMA finalised draft Implementing Technical Standards in October 2025 that extend the alleviated (simplified) insider list format, previously reserved for issuers on SME Growth Markets such as the Euronext Growth or First North, to all EU issuers.

The current insider list templates have been consolidated into three:

• An event-based section template
• A permanent insiders section template
• A lighter template for persons with regular access to inside information on SME Growth Markets

The MAR data requiring collection has also been reduced. Personal data including surname at birth, personal telephone number, and personal home address are no longer required in the simplified EU templates.

The new insider list format applies from 5 July 2026 under Commission Implementing Regulation (EU) 2026/1291, which repeals and replaces Implementing Regulation (EU) 2022/1210.

Where a company is going through a protracted process, any intermediate step that constitutes inside information still triggers the obligation to maintain an insider list, even though the disclosure of that step itself may no longer be required separately.

UK MAR has not changed

EU MAR was onshored into UK law on 31 December 2020 as UK MAR. Since that date, the two regimes have been independent, but largely identical. None of the EU Listing Act changes are directly applicable to UK-listed companies and UK MAR has not been amended. There is also no indication that the UK intends to replicate the reforms in the EU Listing Act.

There is no corresponding change to the insider list format under UK MAR, UK-only issuers can continue to use the templates set out in the UK version of Implementing Regulation (EU) 2016/347.

This means the EU and UK regimes have now diverged in a way that is operationally significant for the first time since Brexit.

Insider list requirements are unchanged and actively enforced

UK insider list templates are set by the UK version of Implementing Regulation (EU) 2016/347 and are legally binding.

The FCA has not adopted the EU’s simplified data fields. Personal telephone numbers and national identification numbers (National Insurance numbers for UK nationals) must still be included. In addition, personal data for all contractors must still be provided.

In Market Watch 71 (December 2022), the FCA stated it ‘has not made the changes which the EU has made to its Technical Standards for insider lists for SME Growth Market issuers’. In the same publication, it noted that it expects issuers to produce insider lists promptly on request, for example within two days. Nothing since has changed that position, and it remains the clearest statement of the FCA’s stance.

What this means for dual-listed companies

An issuer with securities listed or admitted to trading in both London and a European jurisdiction must now navigate two separate regimes with different approaches to insider lists and the disclosure of inside information.

Regarding insider lists specifically, from 5 July 2026, the dual-listed issuer must maintain EU-format lists (under the new simplified templates) for EU-admitted instruments and UK-format lists (under the 2016/347 templates, including full personal data fields) for UK-admitted instruments. UK MAR has not adopted the simplified templates, so dual-listed issuers now face different documentation requirements under each regime.

Both the FCA and an EU-member state regulator can request copies of insider lists at any time.

The EU’s new simplified insider list format goes further than the existing SME Growth Market exemptions available to AIM issuers under Article 18(6) UK MAR. That broader simplification is not available to any UK issuer.

The practical consequence for compliance teams at dual-listed issuers is managing two insider list formats with different data field requirements simultaneously.

Practical implications for governance and compliance teams

For those whose companies operate in the EU, the operational burden has not disappeared, but it has shifted. Intermediate inside information still triggers the obligation to maintain an insider list. Governance and compliance teams should expect longer confidentiality phases and larger, evolving insider groups to manage as a result.

By contrast, for UK issuers, the practical test is not a question of efficiency, but whether they can withstand regulatory scrutiny. The FCA has been explicit in stating that it will expect prompt production and adherence to the required format for requested insider lists.

Issuers still relying on manual tools such as spreadsheets and email-based workflows should assess compatibility with the required template structure, version control, and the ability to produce lists at short notice.

What issuers should consider now

For EU-listed companies, the task is operational: insider lists must move onto the new event-based, permanent insiders, and SME regular access templates, using the simplified data fields. Lists still held in the old five-template format will not meet the new requirement. Insidertrack has been updated to reflect these simplified insider list templates, so your EU-format lists are compliant with the new requirements.

For those operating only within UK markets, your insider list obligations are unchanged. The proactive question revolves around whether your current tools and processes can meet them under scrutiny, particularly with regards to the FCA’s expectation of prompt production in the prescribed format.

For dual-listed issuers, the divergence between UK and EU insider list formats from 5 July 2026 adds a layer of operational complexity where both formats may need to be reported.

Insidertrack is built to maintain audit-ready insider lists under UK and EU MAR and respond to regulator requests at short notice. Book a demo to see how it works in practice.