An integrated banking transaction services (IBTS) module receives an instrument from a client to initiate a brokerage transaction between a broker-dealer and an investment firm. The IBTS module transmits a notification message to a broker-dealer that the instrument was presented. The IBTS module receives a confirmation message from the broker-dealer that includes information as to whether to pay the instrument. If the instrument is to be paid, the IBTS module transmits information associated with the brokerage transaction to a sub-accounting engine.