If you’re still waiting for the benefits of Brexit, we might finally have one: the FCA is cutting MiFID transaction reporting requirements further and faster than ESMA can and will.

PS26/15, published on 03 August 2026, confirms the rules consulted on in CP25/32. The regime is narrowed, the report is shortened, and the default back-reporting period is reduced, for an estimated £115.3m in annual savings. The rules take legal effect on 3 April 2028, but the FCA opens a flexible supervisory window from 3 August 2026, so most of the relief is available almost immediately.

Key takeaways

• PS26/15 finalizes the CP25/32 proposals. The rules are binding from 3 April 2028, with a flexible supervisory approach from 3 August 2026.

• FX derivatives and around 7 million EU-only instruments leave scope, and most corporate event activity is exempted.

• The transaction report falls from 65 fields to 52.

• The default back-reporting period drops from five years to three, effective immediately.

• The draft schema, validation rules and guidelines follow in October 2026, bundled into a new Transaction Reporting User Pack.

What changes under PS26/15: before and after

Firms can apply the relaxations immediately

The rules take legal effect on 3 April 2028, but from 3 August 2026 the FCA is taking a flexible supervisory approach across a defined list of areas, not acting against firms that depart from current requirements and not expecting error correction or notification in those areas.

From that date a firm can stop reporting EU-only instruments and FX derivatives, drop the exempted corporate event activity, leave the removed fields empty, provided that the message remains valid, and apply the three-year back-reporting horizon. Back reporting relaxes from day one. The field relaxations follow once the FCA, along with any intermediaries, switch off the relevant validation rules in October 2026.

FX derivatives leave scope, along with EU-only instruments

The regime is narrowed on two fronts.

Geographically, it will apply only to instruments tradeable on UK trading venues, removing around 7 million instruments only tradeable on EU venues. The FCA will treat the Financial Instruments Reference Data System (FIRDS) as the golden source for reportability and is considering ceasing to ingest EU reference data into the register before April 2028. The gap on EU-venue activity is covered by data the EU national competent authorities (NCAs) already hold and by ad hoc requests.

FX derivatives leave scope entirely, affecting over 400 UK firms, on the basis that UK EMIR is the better source. During the implementation period the relief is conditional on submitting UK EMIR data for the same transactions, so firms outside UK EMIR, notably UK branches of third-country firms, must keep reporting until the EMIR work closes that gap.

Most corporate event activity is also exempted, with initial public offerings (IPOs), secondary offerings, placings and debt issuance retained.

Clearer rules for OTC derivative reportability

The FCA has added guidance on when over-the-counter (OTC) derivatives are reportable by reference to FIRDS data, easing the long-standing difficulty of determining whether a derivative is traded on a trading venue and so in scope.

Two concessions help where matching is hard: firms may voluntarily over-report index derivatives, and basket instruments may be reported with an International Securities Identification Number (ISIN) whose underlyings include instruments that are not in FIRDS. Index and Basket component eligibility have always presented challenges, so these lower the burden somewhat, although the central problem of identifying all the constituents and testing them for TOTV status remains. 

The transaction report falls from 65 fields to 52

Each removed field is derivable from the Classification of Financial Instruments (CFI) code or reference data, duplicative of data already held, or of low supervisory value.

• Transmission of order indicator (Field 25)

• SwpIn/SwpOut XML tags (used today for Swap Leg Identification)

• Derivative notional increase/decrease  (Field 32)

• Option type (Field 50)

• Exercise style Field 53)

• Delivery type (Field 56)

• Maturity date (Field 54)

• Notional currency 2 (Field 45)

• Waiver indicator (Field 61)

• Short selling indicator (Field 62)

• OTC post-trade indicator (Field 63)

• Commodity derivative indicator (Field 64)

• Securities financing transaction indicator (Field 65) 

The FCA also codifies several data-quality rules: a trust Legal Entity Identifier (LEI) waterfall, pre-trade capture of natural person identifiers, deterministic CONCAT generation, and consistency between trading capacity and the buyer/seller fields. It also relieves trading venues of a set of instrument reference data fields.

Back reporting falls from five years to three

The default period for correcting reporting errors drops from five years to three, under new guidance at MAR 14.15.4G, which the FCA expects to cut corrective resubmissions by around a third. This applies immediately from 3 August 2026.

The FCA keeps the ability to require five years on an exceptional basis for serious failings, and the five-year record-keeping obligation under COBS 11 and SYSC 9 is unchanged. It declined both a further cut to two years and a standalone amend function.

What firms should do now

With relief available from August but the specifications due in October, the near-term task is to decide where to take early relief and prepare for the pack rather than to build. Firms should map trading flows against the revised scope to determine if early relief is applicable, and whether it’s convenient to change now. Even with immediate FCA flexibility, ARM requirements may be different.

The practical question is how much engineering a 65-to-52 field change costs you. On a platform where the reporting logic is configuration rather than code, absorbing the October pack is a controlled change, not a rebuild.

Talk to KOR about what PS26/15 means for your UK MiFIR reporting. [Book a walkthrough]

Frequently asked questions

When do the FCA's PS26/15 rules take effect? The PS26/15 rules take legal effect on 3 April 2028. However, the FCA opens a flexible supervisory approach from 3 August 2026, so firms can apply most of the relief immediately. The draft schema and validation rules arrive in October 2026, and field-level relaxations become usable once the FCA switches off the corresponding validation rules.

How many fields are in the new UK transaction report? The UK transaction report falls from 65 fields to 52 under PS26/15. Thirteen fields are removed, including option type, exercise style, delivery type, maturity date, notional currency 2, the transmission of order indicator, the SwpIn/SwpOut tags, derivative notional increase/decrease, and the five indicator fields at RTS 22 fields 61 to 65.

Are FX derivatives still reportable under UK MiFIR? FX derivatives leave the UK MiFIR transaction reporting regime entirely under PS26/15, affecting over 400 UK firms, because the FCA considers UK EMIR the better source. During the implementation period the relief is conditional on submitting UK EMIR data for the same transactions, so firms outside UK EMIR must keep reporting for now.