Due to the T+2 settlement rule, you normally have 2 business days to cover the call once the call is issued.

For example, you have until Wednesday afternoon to cover your margin call which was generated on Monday morning. However, due to market volatility, the deadline to cover your margin call could be sooner than 2 business days.

Please note: brokerage firms are not obligated to inform you before the force liquidation for a margin call.