A system and method for dynamic selection of a database identifier based on application program requirements in a Financial Service Organization (FSO) business transaction processing system. Developers may build application programs for FSO business transactions with increased flexibility to changing business requirements and reduced development time. Dynamic database packageset software may provide functionality to isolate the FSO application program source code from changes to the FSO database. A dynamic database packageset switching table may include user defined keys and their associated database identifier values. The dynamic database packageset switching software may provide functionality to build a key, in real-time with a pre-defined structure, based on application program parameter values, use the key to access the dynamic database packageset switching table to locate an associated database identifier and access an FSO database using the database identifier to retrieve requested FSO data.