The EU EMIR Refit went live in April 2024, bringing the most significant change to derivatives trade reporting in the EU since EMIR was first introduced. The field count expanded from 88 to 203 reporting fields. ISO 20022 XML became mandatory as the reporting format. The Unique Trade Identifier waterfall, as set out in Article 4 of Commission Delegated Regulation (EU) 2022/1855, established a priority sequence for UTI generation. For EU-regulated counterparties, these changes were live as of 29 April 2024.
For UK-regulated firms, the picture is different. UK EMIR, which is the retained version of EU EMIR as amended by the UK Benchmarks and EMIR (Amendment) (EU Exit) Regulations 2019, has followed a separate reform path. The FCA has been consulting on UK EMIR revisions through its own process, and the current state of UK EMIR reporting requirements diverges from the post-Refit EU position on several points, including field count, format mandates, and UTI generation rules.
The compliance challenge for UK firms with EU-facing derivatives portfolios is managing dual-track reporting obligations: UK EMIR requirements for UK-regulated activity and EU EMIR post-Refit requirements where the counterparty is EU-regulated or where trades are on EU trading venues. This article covers both tracks and the ongoing ESMA consultation that will affect the EU side of that picture.
EMIR Refit Go-Live: What Changed in April 2024
The April 2024 go-live of EU EMIR Refit changed reporting across several dimensions. The field count expansion from 88 to 203 fields reflected both new reporting requirements (additional collateral fields, new counterparty classification fields, new margin fields) and the disaggregation of existing composite fields into component fields. Firms that had built reporting systems around the 88-field structure needed either system updates or the use of delegated reporting services that absorbed the mapping complexity.
The ISO 20022 XML format mandate replaced the previous CSV-based reporting format. Trade repositories transitioned to accepting the new format from go-live. Firms reporting through delegated service providers had the format translation managed on their behalf. Firms with internal reporting systems needed format compliance by the go-live date. The FCA confirmed that UK EMIR would not mandate ISO 20022 XML at the April 2024 date, creating an immediate format divergence between the two regimes.
The UTI waterfall under EU EMIR post-Refit gives priority to the UTI generated by the execution venue (if applicable), then the CCP (if centrally cleared), then the entity responsible for reporting if neither applies. Annex I of Commission Delegated Regulation (EU) 2022/1855 sets out the UTI format and generation requirements. For UK EMIR, the UTI rules remain under the pre-Refit ESMA guidelines as retained in UK law, with FCA guidance on areas of specific divergence. Where a trade involves a UK counterparty and an EU counterparty, the UTI generated for UK EMIR reporting purposes and the UTI generated for EU EMIR reporting purposes may differ if the generation rule differs under the two regimes.
The 2026 ESMA Consultation: What Is Proposed
ESMA published a targeted consultation in 2025 addressing three areas of the post-Refit framework: reporting timeline adjustments, UPI specification alignment for field 26, and the treatment of collateral reporting fields 89 to 100. The consultation was open for industry response, with ESMA targeting finalised technical standards in 2026.
The reporting timeline proposals would adjust the T+1 reporting deadline for certain categories of trade modification report. ESMA's analysis of the first months of post-Refit reporting identified a subset of trade lifecycle events where the T+1 deadline created operational difficulty for counterparties, particularly for complex structured products and for certain cross-currency transactions. The consultation proposes extending the reporting deadline to T+2 for specific event types.
The UPI specification alignment for field 26 addresses a divergence between ESMA's implementation of the Unique Product Identifier requirement and the CPMI-IOSCO technical guidance that established the UPI standard. Field 26 in the post-Refit template specifies how the UPI should be populated for derivatives not covered by the main UPI lookup service. The consultation proposes alignment between ESMA's implementation and the updated CPMI-IOSCO guidance on these edge-case instruments.
The collateral reporting fields 89 to 100 consultation addresses the initial margin reporting requirement. Field 94, which records posted initial margin, has been the subject of industry feedback noting ambiguity about whether the field should record initial margin at the portfolio level or the individual trade level for cleared transactions. ESMA's consultation proposes clarifying guidance, with the expectation that firms will need to assess whether their current reporting for field 94 aligns with the proposed clarified standard.
UK EMIR Divergence: The Three Scenarios That Matter
For UK firms, EU EMIR divergence matters in three specific scenarios. The first is UK firms with EU-licensed subsidiaries. An EU-licensed subsidiary of a UK parent is subject to EU EMIR directly. The subsidiary's reporting obligations are the post-Refit EU EMIR requirements, not UK EMIR. Where the parent provides reporting infrastructure to the subsidiary, that infrastructure must be capable of EU EMIR post-Refit output, regardless of the parent's UK EMIR posture.
The second scenario is UK firms trading with EU financial counterparties where the EU counterparty exercises its right under EU EMIR to delegate reporting to the UK counterparty. In this case, the UK firm reports on behalf of the EU counterparty under EU EMIR rules, not UK EMIR rules. The UK firm's reporting system must be capable of generating a compliant EU EMIR post-Refit report for those trades.
The third scenario is UK firms that were active in pre-Refit EU EMIR reporting before April 2024 and have maintained their EU EMIR reporting capability post-Refit for their EU-facing book. These firms have a compliance obligation to ensure their EU EMIR post-Refit reporting is accurate, and the ESMA consultation proposals, when finalised, will require assessment of whether current reporting for fields 26 and 89 to 100 aligns with the finalised standards.
The FCA's UK EMIR Reform Track
The FCA published a consultation on UK EMIR trade reporting reforms in 2023 (CP23/4) and has been progressing technical standards development in parallel with the ESMA process. UK EMIR is expected to move toward greater field count alignment with the EU post-Refit standard over the reform period, but the UK timeline and format requirements are expected to differ from the EU implementation. Compliance teams tracking UK EMIR should monitor FCA policy statement publications on CP23/4 and subsequent instruments, which will specify the UK implementation timeline and final field requirements.
We are not saying that UK EMIR will converge entirely with EU EMIR post-Refit. The FCA has been explicit that post-Brexit UK regulatory reform is not an exercise in mirroring EU rules. The reform process is expected to produce a UK-specific framework that is compatible with international standards but distinct from the EU implementation in certain respects. For firms managing dual-track reporting, the compliance obligation is to track both reform processes independently and maintain systems capable of satisfying both.
Ongoing Monitoring Requirements
The ESMA consultation timeline means that finalised technical standards on the three proposed areas are expected in 2026. For UK firms with EU EMIR reporting obligations, the compliance calendar includes the following monitoring milestones: the ESMA consultation close, ESMA's publication of final technical standards, the European Commission's endorsement process, and the effective date of any amended field requirements. Each of those milestones may require an assessment of whether current reporting systems and processes need to be updated.
Kalipso monitors ESMA publications alongside FCA and PRA publications. When ESMA issues consultation responses, final technical standards, or Q&A updates on EMIR Refit, the compliance team receives an alert. The dual-track monitoring requirement for firms with both UK and EU EMIR obligations means that monitoring ESMA and FCA publications on the same subject in an integrated view is more efficient than maintaining separate processes for each regulatory stream. That is what Kalipso provides for firms in this position.
