IBKR's Family Advisor and Non-Professional Advisor solutions let you manage, trade and report on multiple accounts from a single master account. The Family Advisor and Non-Professional Advisor accounts allows you to manage 15 or fewer accounts of varying types under a single login including Individual, Joint, Trust, IRA, UGMA/UTMA, Corporation, Partnership, Limited Liability Company, and Unincorporated Legal Structures. The specific limits vary by jurisdiction and the types of accounts in the structure.
For more information, please review the webpage for IBKR's Family Advisor and Non-Professional Advisor account structure.