FCA publishes final rules for UK transaction reporting

What does this mean?

The current UK MiFIR transaction reporting framework will be replaced by new rules in the FCA’s Market Conduct Sourcebook (MAR). The changes narrow the reporting perimeter and shorten the default back-reporting period, while retaining buy-side reporting and core expectations for data quality and controls.

The FCA estimates annual savings of over £100m for firms, mainly through fewer data collection, validation and submission requirements. However, the implementation period to 3 April 2028 reflects the scale and complexity of the associated system, process and governance changes firms will need to make to comply with the new regime and realise its benefits.

Scope and reportability

The reporting perimeter will be narrowed, with clearer rules for determining whether instruments and transactions are reportable, including:

• Limiting scope to UK-venue instruments: Remove reporting obligations for 7 million instruments that are only tradeable on EU trading venues.

• Excluding FX derivatives from MiFIR transaction reporting: Rely instead on UK EMIR data. During implementation, firms not subject to UK EMIR reporting must continue to meet applicable MiFIR reporting requirements. The FX derivatives exclusion does not extend to derivative contracts relating to cryptoassets.

• Making the FCA’s Financial Instrument Reference Data System (FIRDS) the golden source for reportability: Allow firms to conclude that an instrument is not reportable where the instrument or any underlying instrument is not present in FCA FIRDS within seven working days of execution, and introduce UK guidance for determining whether over-the-counter (OTC) derivatives are reportable.

Reporting content and operating model

The FCA is simplifying selected reporting requirements and processes, while also changing the data that firms must capture and submit. 

• Revise reportable data requirements: Bring transaction-reporting fields down from 65 to 52 overall, while replacing certain existing fields and introducing new requirements, including client indicators and package transaction price and currency fields.

• Clarify exclusions: Exclude most corporate event activity and widen the exclusion for eligible post-trade risk reduction services, while retaining reporting for initial public offerings (IPOs), secondary public offerings, placings and debt issuance.

• Simplify trading-venue reporting: Allow venues to use a new code instead of identifying natural-person decision makers when reporting for firms outside the regime, and move instrument-reference-data submissions to an event-driven model.

Following feedback, the FCA will also retain existing counterparty-identification arrangements where the counterparty is unknown at execution, rather than proceeding with its proposal to use the venue’s Market Identifier Code (MIC) in all cases.

Implementation and supervision

The new rules take effect on 3 April 2028. Until then, the FCA will apply supervisory flexibility to selected scope and field changes, allowing firms to make certain changes before commencement where they are ready to do so.

From 3 August 2026, the FCA’s default supervisory expectation for back-reporting is three years rather than five, although it may require five years in exceptional cases. New guidance also sets expectations for triaging, assessing and escalating transaction-reporting incidents and taking remedial action, without introducing a materiality threshold for notifications.

What do firms need to do?

With the final rules now published, firms should begin planning for implementation. The timetable gives firms around 18 months from publication of the supporting materials to commencement, reflecting the scale and complexity of the system, process and governance changes required.

The immediate priority is to map reporting logic, trading scenarios, fields and controls to the final MAR rules. Firms should identify which flows remain reportable, where data capture or field population must change, and whether to use the FCA’s supervisory flexibility before commencement. Decisions on early adoption require clear governance and controls.

The draft schema, validation rules and new guidelines, due in October 2026, should be used to confirm system changes and testing plans. Delivery will require coordination across front office, operations, compliance, technology and data teams, as well as ARMs, trading venues and vendors. Client, broker and delegated-reporting arrangements may also need updating. Firms should assess whether conditional single-sided reporting offers practical benefits, given the contractual, data-sharing and reconciliation arrangements required.

Global firms should assess the UK rules against EU and other jurisdictional requirements. They should determine whether a common reporting architecture remains viable or UK-specific logic and controls are needed, while avoiding parallel processes and rework.

Next steps

The FCA will publish a draft schema, validation rules and guidelines, forming part of a Transaction Reporting User Pack, in October 2026. It will also consult on transitional provisions and consequential Handbook changes. The new regime takes effect on 3 April 2028.