Georgia Code Title 13. Contracts § 13-5-30

(a) To make the following obligations binding on the promisor, the promise must be in writing and signed by the party to be charged therewith or some person lawfully authorized by him or her:

(b) Any agreement to modify, alter, cancel, repeal, revoke, release, or rescind a promise, agreement, contract, or commitment provided for in subsection (a) of this Code section must be in writing and signed by all parties to such agreement; provided, however, that if the party against whom enforcement of such agreement under this subsection is sought admits in a pleading, in testimony, or otherwise in court that the agreement was made, then such agreement is enforceable if valid in all other respects.