THE POSTAL RULE (DOCTRINE OF ACCEPTANCE TO CONTRACT)

The postal rule has three main practical consequences:

1. A postal acceptance can take effect when it is posted, even if it gets lost in the post and never reaches the offeror.
2. Where an acceptance is posted after the offeree posts a revocation of the offer, but before that revocation has been received, the acceptance will be binding (posted acceptances take effect on posting, and posted revocations take effect on communication).
3. The contract is completed at the time of posting, so it has priority over any other contract concerning the same subject matter which was made after the original acceptance was posted but before it had reached the offeror.

Exceptions to the postal rule

• Offers requiring communication of acceptance. An offeror may avoid the postal rule by making it a term of their offer that acceptance will only take effect when it is communicated to them.
• Instant methods of communication. When an acceptance is made by an instant mode of communication, such as telephone or telex, the postal rule does not apply.
• Misdirected acceptance. Where a letter of acceptance is lost or delayed because the offeree has wrongly or incompletely addressed it through their own carelessness, it seems reasonable that the postal rule should not apply, although there is no precise authority to this effect.

Withdrawal of postal acceptance

Where the postal rule applies, it seems unlikely that an offeree could revoke a postal acceptance by phone or some other instant means of communication before it arrives. The Scottish case of Dunmore v Alexander (1830) does appear to be such revocation, though the court’s views were only obiter on this point.