The CAT NMS Plan defines an Allocation Report as “a report made to the Central Repository by an Industry Member that identifies the Firm Designated ID for any account(s), including subaccount(s), to which executed shares are allocated”. This includes the booking of shares/contracts into the same account for which an order was originally placed, and the booking of shares/contracts into an account based on allocation instructions (e.g., subaccount allocations).

Allocation Reports are reported to CAT via the Post-Trade Allocation (MEPA) and Option Post-Trade Allocation events (MOPA). The CAT reporting obligation for allocation events belongs to the firm performing the allocation, which is generally the clearing or self-clearing firm processing the allocation.