Section 509: Offer or acceptance may be revoked

1) The offer or acceptance may revoke his or her offer through a notice.

Provided that, if the offer or acceptance has been received from the offeree, a notice to the effect that he or she has accepted the offer before receiving a notice of revocation of the offer, such an offer shall not be revoked.

2) The offeree may revoke his or her acceptance by notice.

Provided that if the offerer has already received the notice of acceptance before receiving the notice of its revocation, such an acceptance shall not be revoked.

3) The person who has sent a notice expressing his or her refusal of the offer may again send a notice expressing his or her acceptance of the offer.

Provided that, if the notice of refusal out of the notices of refusal or acceptance reaches first, the contract shall not be deemed to have been concluded, and if the notice of acceptance reaches first, the contract shall be deemed to be concluded.

4) If the notice under sub-section (1) has been sent after sending the offer, the notice under sub-section (2) has been sent after sending acceptance, or the notice under sub-section (3) has been sent after sending a notice of refusal, and the concerned person receives such notices at the same time, the contract shall not be deemed to have been concluded.

5) If the offeree sends an acceptance with a condition or with an alteration to the offer sent by the offerer, the offeree shall be deemed to make a counteroffer.