CP26/34: Preparing for the new transaction reporting regime

Key dates

2026-10-02

CP26/34 consultation opened and the FCA published the consultation paper and draft implementation materials.

2026-11-06 Deadline

Deadline for responses to CP26/34.

2027-04-03

FCA target date for publication of the final Transaction Reporting User Pack.

2028-04-03 Deadline

New UK transaction reporting rules in MAR 13, MAR 14 and MAR 15 come into force; FCA systems switch to the new schema and validation rules and UK MiFIR reporting formats cease to be accepted.

Suggested considerations

• Firms should consider submitting responses to CP26/34 by 6 November 2026, particularly on whether the proposed guidance and transitional provisions resolve practical implementation uncertainties.
• Compliance and regulatory reporting teams may wish to map current UK MiFIR reporting processes, fields, instrument populations, back-reporting logic and delegation arrangements against MAR 13, MAR 14 and MAR 15.
• Firms should assess the impact of reducing the reporting-field population from 65 to 52, removing EU-only instruments and excluding qualifying FX derivatives, while separately validating that CFDs, spread bets and other retained instruments remain correctly captured.
• Technology and operations teams should review the FCA draft schema and validation rules, identify data-source and transformation changes, and begin controlled testing before the 3 April 2028 cutover.
• Firms should plan for parallel controls over transaction reports, instrument reference data and order book data during migration, including reconciliation, exception management, resubmission and audit-trail requirements.
• Firms considering conditional single-sided reporting should assess counterparty eligibility, reliance controls, data-quality monitoring, contractual arrangements and fallback procedures before changing reporting responsibilities.
• Compliance teams may wish to distinguish the three-year default back-reporting period from applicable record-retention obligations and maintain evidence supporting any decision to use the reduced lookback.
• Firms should monitor the FCA's planned Q1 2027 consultation and subsequent final Transaction Reporting User Pack, and align implementation governance, vendor deliverables and staff training to the final materials.

What changed

CP26/34 does not propose a new substantive reporting perimeter; it provides implementation detail for the rules introduced in PS26/15. The FCA is consulting on guidance explaining the new rules, transitional arrangements, amendments referring to MAR 13, MAR 14 and MAR 15, and the migration of relevant existing Level 3 Materials into a new Transaction Reporting User Pack. From 3 April 2028, the new regime will replace the existing UK MiFIR transaction reporting framework, and FCA systems will use the new schema and validation rules; firms will no longer be able to submit transaction reports or instrument reference data in UK MiFIR formats. Market commentary identifies the underlying PS26/15 changes as reducing reportable fields from 65 to 52, removing EU-only instruments from scope, excludi

Who is affected

• UK-authorised investment firms subject to transaction reporting requirements
• Operators of UK trading venues
• Approved reporting mechanisms
• Firms submitting instrument reference data or order book data
• Trade associations and other market participants involved in UK transaction reporting

Related regulations

• UK Markets in Financial Instruments Regulation (UK MiFIR)
• MiFID II
• MAR 13
• MAR 14
• MAR 15
• UK EMIR
• UK SFTR
• RTS 22
• RTS 23
• RTS 24