MiFIDII / MiFIR PostTrade Reporting Requirements

Overview

MiFIDII (Markets in Financial Instruments Directive II) and MiFIR (Markets in Financial Instruments Regulation) introduced in January2018 aim to increase transparency, improve investor protection and strengthen market integrity across the European Union. A cornerstone of the regime is the posttrade reporting obligation, which requires almost every transaction in covered instruments to be reported to a national competent authority (NCA) or an approved reporting intermediary (REP).

Who Must Report?

Reporting duties fall on three main categories of market participants:

• Investment firms that execute trades on behalf of clients or for their own account.
• Trading venues (regulated markets, multilateral trading facilities, organized trading facilities) that act as a counterparty to the trade.
• Approved Reporting Intermediaries (ARPs/REPs) entities authorised to submit reports on behalf of other participants.

Both EUbased and nonEU firms that regularly trade EUregulated instruments must have a reporting solution in place, either directly or via a thirdparty REP.

What Must Be Reported?

MiFIDII specifies a core set of data fields, organised into three sections:

In addition to the core fields, certain instruments (e.g., derivatives, structured products) require supplementary data such as underlying asset details, maturity, and settlement currency.

Timing Requirements

Reports must be transmitted to the appropriate repository no later than T+1 business day after the transaction is concluded. For trades executed on a regulated market or an MTF, the venue itself is responsible for reporting within the same deadline. OTC transactions performed by investment firms must submit the report themselves or via a REP.

If a trade is cancelled or amended, a separate cancellation or modification report must be sent within the same T+1 window.

How to Report

Reports are sent using the RTS (Regulatory Technical Standards) format, which aligns with the ISO20022 XML schema. Most firms connect to their national repository via a secure API or a secure filetransfer protocol (SFTP).

Key steps include:

1. Capture the trade data at the moment of execution.
2. Validate the data against the RTS fieldlevel rules (e.g., mandatory fields, value ranges).
3. Enrich the record with LEIs and MICs for counterparties and venues.
4. Encode the data into the XML format defined by the RTS.
5. Transmit the file to the authorised reporting outlet (national repository or REP).
6. Acknowledge receipt and monitor for any rejection messages.

Validation, Rejection & Corrections

National repositories perform automated validation checks. Common reasons for rejection are missing mandatory fields, mismatched LEIs, or invalid timestamps. When a report is rejected, the sender must correct the data and resubmit within the original reporting deadline.

Corrections are classified as:

• Amendments changes to an already accepted report (e.g., price correction).
• Replacements a completely new report that replaces the original (used when the original contains multiple errors).

Both amendment and replacement messages carry a reference to the original transaction ID to preserve auditability.

Penalties for NonCompliance

Authorities can impose administrative fines of up to 5million or 5% of the firms annual turnover for systematic breaches. Repeated failures may lead to restrictions on the firms ability to trade EU instruments, or even suspension of licences. In addition, inaccurate reporting can trigger reputational damage and increase scrutiny from regulators.

Best Practices for Efficient Reporting

• Automate data capture at the frontoffice level to minimise manual entry errors.
• Maintain an uptodate LEI database and ensure the correct MIC is associated with each venue.
• Implement realtime validation before transmission to catch missing or malformed fields.
• Use a central reporting hub or a cloudbased REP service to simplify connectivity with multiple NCAs.
• Archive every report (including acknowledgements and rejection notices) for at least five years, as required by Article28 of MiFIDII.
• Run periodic compliance checks and simulate reporting scenarios to verify that T+1 deadlines are always met.

By embedding these controls into the trade lifecycle, firms can reduce operational risk, avoid costly fines, and contribute to the transparency objectives of the EU market framework.