IBKR provides information on voluntary corporate actions to eligible account holders. Some corporate actions have restrictions associated with them in terms of those shareholders considered eligible for either notification or participation. In the event an action has stated restrictions, IBKR will generally take a broad view and restrict all holders who may fall under the restriction. For instance, if an offer is generally restricted for residents of the United States unless they qualify as QIBs (Qualified Institutional Buyers), IBKR will restrict all clients with residency in the United States from submitting an election.
Clients who have reviewed the full offer details and believe their account is eligible to participate should submit an Inquiry Ticket through the Message Center. Therein, state the security symbol, the exact number of shares you wish to take action on and the action desired (exercise, tender). IBKR will review your request and will process on a best effort basis if possible.
For more information on how IBKR applies restrictions for voluntary corporate actions, please refer to KB 1320.