The Indian Contract Act, 1872
62. Effect of novation, rescission, and alteration of contract-
If the parties to a contract agree to substitute a new contract for it, or to rescind or alter it, the original contract need not be performed.
(a) A owes money to B under a contract. It is agreed between A, B and C, that B shall thenceforth accept C as his debtor, instead of A. The old debt of A to B is at an end, and a new debt from C to B has been contracted.
(b) A owes B 10,000 rupees. A enters into an agreement with B, and gives B a mortgage of his (A’s), estate for 5,000 rupees in place of the debt of 10,000 rupees. This is a new contract and extinguishes the old.
(c) A owes B 1,000 rupees under a contract, B owes C 1,000 rupees, B orders A to credit C with 1,000 rupees in his books, but C does not assent to the agreement. B still owes C 1,000 rupees, and no new contract has been entered into.
Alteration of Contracts
Person entering into agreement under section 8(1)(a) of Requisition and Acquisition of Immovable Property Act cannot later claim a legal right to obtain a court order directing reopening of the agreement, just because a subsequent award granted higher compensation for land similar to his own; Dayal Singh v. Union of India, (2003) 2 SCC 593.
If the parties to a Contract agree
The plaintiff Bank had agreed that the defendants could pay the amount of Rs.10,00,000 which would be convenient to both the parties subsequent to the filing of the suit. The parties have entered into a second agreement to supersede the liability and the entitlement formulated through the transaction and that under the circumstances the said subsequent agreement squarely comes within the ambit of section 62 of the Act; Central Bank of India v. V. G. Naidu & Sons (Leather) Pvt. Ltd., AIR 1992 Mad 139.
A material alteration is one which varies the rights, liabilities or legal position of the parties as ascertained by the deed from its original state, or otherwise varies the effect of the instrument as originally expressed or reduces to certainty some provisions which were originally unascertained and as such void, or which may otherwise prejudice the party bound by the deed as originally executed. The effect of making such an alteration without the consent of the party bound is exactly the same as that of cancelling the deed. The last line in the schedule of property regarding delivery of possession was held to be inserted not on the date of execution of agreement but subequent to it and have material alteration; Janab M. H. M. Yakoob v. M. Krishnan, AIR 1992 Mad 80.
Where an existing mortgage was replaced by a new agreement of mortgage, the new agreement being not enforceable for want of registration, the parties were still bound by the original mortgage; Shanker Lal Damodhar v. Ambalal Ajaipal, AIR 1946 Nag 260.