How can I change the primary bank account linked to a demat account?

You typically raise this request through the broker’s app or website under account settings, or through a formal request form if the broker requires physical or semi-physical processing for this specific change, since changing the primary bank account is treated as a sensitive modification given its impact on where funds get withdrawn. It usually requires submitting proof for the new bank account, like a cancelled cheque or recent bank statement showing your name, along with identity re-verification in some cases. Because this change affects fund withdrawal security, most brokers build in a mandatory cooling-off or hold period, often around 24 to 48 hours, sometimes longer, during which withdrawals may be temporarily restricted as a fraud-prevention measure. You plan around this delay if you’re changing your primary bank account ahead of a withdrawal you need soon, rather than assuming the change takes effect instantly.