Acceptance must be communicated to the offeror. This can be done either orally or in writing. Where the means of communication is instantaneous (ie face-to-face, telephone, fax or email) the contract will come into being when and where the acceptance is received. If it is posted it is deemed effective from the time of posting.
It is important to differentiate the acceptance of an offer from the acceptance of the goods or services to which the contract relates. For information see also, rejection of goods or services.