In an electronic trading system, prime brokerage services may be provided by assigning one or more dependent or child deal codes to a deal code. Prime broker trades are conducted via the dependent deal codes but appear to the market as deals with the parent deal code using credit assigned to the parent deal code. The prime bank customer is a dependent deal code of the customer bank which also trades on the system, allowing credit to be allocated by the customer dependent code for prime broker trades. A deal code may have several dependent deal codes which can trade with one another. Dependent deal codes can be used to expand the size of trading floors beyond that which can be supported by a single deal code and to assist in migration between system versions.