mailbox rule

mailbox rule

A rule of contract law that says if an offer is made in such a manner that it would be reasonable to assume that another person would accept the offer by placing a letter or other writing in the mail, then acceptance is deemed to have occurred when the writing was placed in the mail,not when it was received by the person making the offer.For example,this is important when a property owner offers,in writing,to sell a particular property for a specified sum.The potential purchaser decides to accept the offer and mail the acceptance to the owner.Before the owner receives the letter, but after it is mailed, the owner decides to withdraw the offer and takes the property off the market or increases the price.In this example,the owner cannot do so because the purchaser has already accepted the offer; it cannot be withdrawn. There is now a contract; there is no longer an offer capable of revocation.