Communication of offer and acceptance and revocation of proposal and acceptance has been provided under sections 3 to 9 which is specified in Chapter I of the Indian Contract Act, 1872.

Communication of Proposal and Acceptance According to section 3, the communication of acceptance of proposals is deemed to be made by an act or omission of the party proposing, accepting, or revoking by which he intends to communicate such acceptance or revocation or which has the effect of communicating it.

Example:  A makes an offer to B to sell his house through a letter when the letter of an offer is received by B and B reads it. Then the communication offer is said to be completed. And, when B accepts the offer and post a letter of his acceptance to the offer and it is received by the offeror and A read it. Then the communication of acceptance to the offer is said to be completed.

Communication When Complete The communication of acceptance is completed when the acceptance of the offer is communicated and comes to the knowledge of a person who makes the proposal. This means, the offeror must be communicated properly and has knowledge that the offeree has been accepted the offer made by the offeror.

Revocation of Proposal and Acceptance According to section 5, the proposal may be revoked before the communication of acceptance is complete as against the proposer. A proposal may be revoked at any time before the communication of its acceptance is complete as against the proposer, but not afterwards. So, section 5 of the Indian Contract Act, will be discussed in two sub-points i.e. revocation of proposal and revocation of acceptance.

Modes of Revocation Section 6, prescribes the modes of Revocation of offer and acceptance in the contract law. This section provides 4 ways for the revocation of the offer. 1. By communication of notice, 2. By the lapse of time, 3. By the failure of the condition precedent, 4. By insanity or death of the proposer.

1. By Communication of Notice When the offer is made to the offeree and the offeror wants to cancel (revoke) the formation of a contract with the other party, the offeror can communicate with the offeree through the notice of revocation of an offer. But, such communication of revocation of an offer shall be made before the offeree gives its acceptance to the offer.

2. By Lapse of Time When the offer is made to the offeree and if there is prescribed time for accepting the offer imposed by the offeror to the offeree. Then the acceptance to that offer must be given within the prescribed time only after that the offer is automatically be terminated.

3. By Failure of the Condition Precedent When the offer is made with certain conditions then the offeree should fulfil all the conditions which are prescribed by the offeror in his offer. If the acceptor failed to fulfil the conditions then the offer will automatically be terminated.

4. By Insanity or Death of Proposer When the offer is made to the offeree, if the offeror died or becomes insolvent (not capable to enter into a contract) and it comes to knowledge of the offeree before completion of communication of acceptance to the offer then the offer is automatically be terminated.