A spin-off is considered a mandatory corporate action. Clients do not need to take action on mandatory corporate actions. IBKR will process mandatory corporate actions on effective date, or upon receipt of the new shares or funds from the depository or clearing agent.
Should a company announce a voluntary corporate action, IBKR will review the terms of the offer and will make the offer available for election if possible. Should an election window open, IBKR will send notification to holders of record.