Issue a stop payment order to the Bank on which it is drawn. Please note that you may have to file the order with the home branch that too expeditiously. But, donu2019t ever give a blank signed cheque to any one. When you give it away, you will come to know of the amount filled in only after the cheque is paid. It is highly unlikely that you will come to know of this beforehand. The cheque will be bounced if a larger sum than the amount available in the account is filled & presented for payment. Such an event would affect your credit score & there is a likelihood of proceeding against you in a court of law. Issuing a blank signed cheque is fraught with multiple risks. So, donu2019t ever even imagining of doing it.