According to Section 2(b), the term ‘acceptance’ is defined as follows:
“When the person to whom the proposal is made signifies his assent thereto, the proposal is said to be accepted. A proposal, when accepted, becomes a promise. “
An acceptance in order to be valid must be absolute, unqualified, accepted according to the mode if any prescribed within the reasonable time and communicated to offeror. Acceptance can also be made by way of conduct.
The legal provisions relating to communication of acceptance are contained in Section 4.
The communication of an acceptance is complete:
a) as against the proposer, when it is put in a course of transmission to him, so as to be out of power of the acceptor;
b) as against the acceptor, when it comes to the knowledge of the proposer.
Section 3 of the Act prescribes, in general terms, two modes of communication, namely:
1) by any act or
2) by omission intending thereby communicate to the other or which has the effect of communicating it to the other.
The first method would include any conduct and words whether written or oral. Written words would include letters, telegrams, advertisements, etc. Oral words would include telephone messages. Any conduct would include positive acts or signs so that the other person understands what the person acting or making signs means to say or convey. Omission would exclude silence but include such conduct or forbearance on one’s part that the other person takes it as his willingness or assent. These are not the only modes of communication of the intention of the parties. There are other means as well, e.g., if you as the owner, deliver the goods to me as the buyer thereof at a certain price, this transaction will be understood by everyone, as acceptance by act or conduct, unless there is an indication to the contrary.
The phrase appearing in Section 3 “which has the effect of communicating it”, clearly refers to an act or omission or conduct which may be indirect but which results in communicating an acceptance or non-acceptance. However, a mere mental but unilateral act of assent in one’s own mind does not tantamount to communication, since it cannot have the effect of communicating it to the other.