Which of the following are the conditions for revocation of offer to be valid?

A revocation of offer is the withdrawal of a previous offer to engage in some sort of legally binding contract. The previous offer had to have been such that it would have immediately become legally binding if the other party had formally agreed to it.

A core ruling defining revocation of offers was established by Payne v. Cave. This case established that neither party is bound to an agreement until an offer has been made by one and formally accepted by the other.

If an offer has been made, the offering party has a right to withdraw it up to formal acceptance by the offeree. Revocation basically serves as formal, legally verifiable notice that a withdrawal was made, and it's valid so long as it is communicated to the offeree before they accept.

The case of Byrne v. Van Tienhoven supports this by establishing that the withdrawal of an offer by telegram is only valid if the telegram is received before the offer is accepted. The case of Dickinson v. Dodds further establishes that the party making the offer can communicate the revocation through a third party.