When is a valid purchase contract created using the post office?

A valid purchase contract is established when the offeree, typically the buyer, puts the acceptance in the mail. This aligns with the "mailbox rule," a legal principle which states that an acceptance is considered effective when it is sent, rather than when it is received by the offeror. This means that as soon as the buyer sends the acceptance through the mail, the contract is deemed valid and binding.

This principle is crucial in real estate transactions, as it creates certainty for both parties regarding when the agreement is officially in place. Other scenarios, such as the seller signing the contract or the buyer presenting the contract in person, do not culminate in a valid contract until the acceptance is communicated according to the mailbox rule. Even delivery by certified mail focuses on the act of delivering documentation rather than establishing the precise moment of acceptance. Thus, the act of mailing the acceptance solidifies the formation of the contract.