Investment firms must report complete and accurate details of transactions in financial instruments to the competent authority as quickly as possible and no later than the close of the following working day. The competent authority shall ensure the information is shared with the authority of the most relevant market by liquidity, the authorities supervising the transmitting firms and any branches involved, and the authority supervising the trading venue, and shall make reported information available to ESMA. The obligation covers instruments admitted to or traded on a trading venue or with a request for admission, instruments whose underlying is such an instrument or an index/basket of such instruments, and OTC derivatives referred to in Article 8a(2).

Reports must include instrument identifiers and numbers, quantity, execution and effective dates and times, transaction prices, client identification, designation of the party on whose behalf the transaction was executed, designation of persons and computer algorithms within the firm responsible for the investment decision and execution, the entity subject to reporting and means of identifying investment firms; venue-executed trades must include the trading venue transaction identification code and off-venue trades the transaction type per regulatory technical standards; commodity derivatives must indicate whether the transaction objectively reduces risk. Reports may be submitted by the investment firm, an ARM or the trading venue; investment firms retain responsibility for completeness, accuracy and timeliness except for failures attributable to an ARM or trading venue and must take reasonable steps to verify reports. ESMA is mandated to develop regulatory technical standards and to report on the functioning and integration of transaction reporting by specified dates.