Uses of accounting unit and account overrides
You use accounting unit overrides or account overrides if you are posting from or posting to multiple accounting units or accounts, or if the source for an allocation includes multiple accounting units or accounts. Whether the accounting units or accounts are used for the post from or post to depends on the posting options that you choose.
The application uses the override information before the Post From fields to determine the source of an allocation. If you define only partial information on the Override tabs, then the system uses information in the Post From fields.
You can also use accounting unit or account overrides to post to contra accounting units or accounts.