Portfolio Subaccounts (Large Account Structures)

Used in tiered account structures (such as Financial Advisor and IBroker Accounts) to return a list of sub-accounts, paginated up to 20 accounts per page, for which the user can view position and account-related information. This endpoint must be called prior to calling other /portfolio endpoints for those sub-accounts. If you have less than 100 sub-accounts use /portfolio/subaccounts. To query a list of accounts the user can trade, see /iserver/accounts.