I only see one of my family’s accounts after logging in - how do I view the others?

Each IBKR account is only allowed one paper trading account. If you have multiple IBKR accounts, each one can have its own paper trading account.

To open a second paper trading account:…

If you do not see a linked account available in the drop down account selector, it is likely due to the fact that the account in question does not have approved trading permissions for the product. For instance, if you have 2 linked accounts and only 1 has approved US stock trading permissions, only that account with approved permissions will be reflected on the trading platform. …

Securities in one Interactive Brokers (IBKR) account cannot be used as collateral for linked accounts. Each IBKR account is treated as a separate entity and stands on its own, even if multiple accounts are linked under the same username. This means that:…

For cash transfers if you are submitting a full account transfer then you can send one request that includes CAD and USD currency when using ATON but if you are submitting a partial account transfer than you will need to send one request for each currency when using ATON…