Literally the word ‘void’ means ‘not binding in law’. Accordingly the term. ‘void contract’ implies a
useless contract which has no legal effect at all. Such a contract is a nullity, as for there has been no contract at all. Section 2(j) defines:

“A contract which ceases to be enforceable by law becomes void, when it ceases to be enforceable.”

It follows form the definition that a void contract is not void from its inception and that it is valid
and binding on the parties when originally entered but subsequent to its formation it becomes invalid and destitute of legal effect because of certain reasons

The reasons which transform a valid contract into a void contract, as given in the contract Act. Are as follows.

(a) Supervening impossibility (sec. 56) – A contract becomes void by impossibility of performance after the formation of the of contract for example; A and B contract to marry each other. Before the time fixed for the marriage, A goes mad. The contract to marry becomes void.

(b) Subsequent illegality (sec, 56) – A contract also becomes void by subsequent illegality. For example, A agrees to sell B 100 bags of wheat at Rs. 650 per bag. Before delivery the government bans private trading in wheat. The contract becomes void.

(c) Repudiation of a voidable contract. A voidable contract becomes void, when the party, whose consent is not free, repudiates the contract. For example, M by threatening to murder B’s son, makes B agree to sell his car worth Rs.30,000 for a sum of Rs. 10,000 only. The contract, being the result or coercion, is voidable at the option of B. B may either affirm or reject the contract. In case B decides to rescind the contract, it becomes void.

(d) In the case of a contract contingent on the happening of an uncertain future event, if that event becomes impossible. A contingent contract to do or not to do something on the happening of an uncertain future event, becomes void, when the event becomes impossible
(sec.32).” for example, A contracts to give Rs. 1,000 as loan to B marries C. C dies without being married to B. the contract becomes void.