Your host processing system may have intrinsic rules about account usage (e.g., whether it is allowable to Book Transfer funds into or out of a particular account type).
The Business Banking system is designed to conform to any such rules that the host system passes along, but it does so in a transparent fashion – that is, it simply does not offer invalid choices. In all services that use drop-down lists to let you choose accounts, the system populates the account lists only with allowable accounts.
In practical terms, this means that you should not expect to see every account in the system listed on every drop-down list. However, please be aware that some host processing systems have restrictions on account usage that are not passed to the Business Banking system, these accounts will still display in the drop down list. If one of these accounts is selected and a transaction is initiated, the host will reject the transaction due to account flag restrictions.