A “negotiable instrument” means a promissory note, bill of exchange or cheque payable either to order or to bearer.
A promissory note is a financial instrument that contains a written promise by one party (the note's issuer or maker) to pay another party (the note's payee) a definite sum of money, either on demand or at a specified future date.
u/s 4, a promissory note is: A “promissory note” is an instrument in writing (not being a bank-note or a currency-note) containing an unconditional undertaking signed by the maker, to pay a certain sum of money only to, or to the order of, a certain person, or to the bearer of the instrument. Illustrations A signs instruments in the following terms:—
(a) “I promise to pay B or order Rs. 500.”
(b) ‘‘I acknowledge myself to be indebted to B in Rs. 1,000, to be paid on demand, for value received.”
(c) “Mr. B. I.O.U. Rs. 1,000.”
(d) “I promise to pay B Rs. 500 and all other sums which shall be due to him.”
(e) “I promise to pay B Rs. 500 first deducting there out any money which he may owe me.”
(f) “I promise to pay B Rs. 500 seven days after my marriage with C.”
(g) “I promise to pay B Rs. 500 on D’s death, provided D leaves me enough to pay that sum.”
(h) “I promise to pay B Rs. 500 and to deliver to him my black horse on 1st January next.” The instruments respectively marked (a) and (b) are promissory notes. The instruments respectively marked (c), (d), (e), (f), (g) and (h) are not promissory notes.
Promissory notes are legally binding whether the note is secured by collateral or based only on the promise of repayment. If you lend money to someone who defaults on a promissory note and does not repay, you can legally possess any property that individual promised as collateral.
All Promissory Notes are valid only for a period of 3 years starting from the date of execution, after which they will be invalid. There is no maximum limit in terms of the amount which can be lent or borrowed. The issuer / lender of the funds is normally the one who will hold the Promissory Note.