A person shall not be liable under Section 141 of the Negotiable Instruments Act, 1881 if he proves:

The first proviso to section 141(1) excuses a person who proves "that the offence was committed without his knowledge, or that he had exercised all due diligence to prevent the commission of such offence". Not having signed the cheque is no answer for a person in charge of the business, the Act sets no minimum amount, and a post-dated cheque is still a cheque under section 138.