Postal Acceptance Rule The mailbox rule or the postal acceptance rule (also called deposited acceptance rule) is a term of
common law contracts which determines the timing of
acceptance of an
offer when
mail is contemplated as the medium of acceptance. The general principle is that a contract is formed when acceptance is actually communicated to the offeror. The mailbox rule is an exception to the general principle. The mailbox rule provides that the contract is formed when the letter of acceptance is placed in the (outgoing) mailbox.
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