1. The Offer.An offer, or proposal to do a thing, may be made either by words or signs, either orally or in writing, but in law it is not regarded as an offer until it comes to the knowledge of the person to whom it is made.
Offer by Mail.In commercial transactions when an offer is made by mail, the general rule is that the offerer is entitled to an answer by return mail, but this will not apply in all cases; for ex-ample, where there are several mails each day. In transactions which are not commercial, much less promptitude in answering is required.
When Revocable.An offer which contains no stipulation as to how long it shall continue is revocable at any time until accepted. When an offer is made for a time limited in the offer, no acceptance afterwards will make it binding.
2. The Acceptance.An offer can only be accepted in the terms in which it is made; an acceptance, therefore, which modifies the offer in any particular goes for nothing.
When the Trade’s Complete.The rule that a contract is complete at the instant when the minds of the parties meet is subject to modification where the negotiation is carried on by letter, for here it is impossible that both parties should have knowledge of the moment it becomes complete.
Where an Offer Is Made by Letter, it is generally held that delivering a letter containing an acceptance of the offer completes the understanding. [See Contracts.]