N.Y. Uniform Commercial Code Law § 2-209: Modification, Rescission and Waiver

Section 2--209. Modification, Rescission and Waiver.

(1) An agreement modifying a contract within this Article needs no

consideration to be binding.

(2) A signed agreement which excludes modification or rescission

except by a signed writing or other signed record cannot be otherwise

modified or rescinded, but except as between merchants such a

requirement on a form supplied by the merchant must be separately signed

by the other party.

(3) The requirements of the statute of frauds section of this Article

(Section 2--201) must be satisfied if the contract as modified is within

its provisions.

(4) Although an attempt at modification or rescission does not satisfy

the requirements of subsection (2) or (3) it can operate as a waiver.

(5) A party who has made a waiver affecting an executory portion of

the contract may retract the waiver by reasonable notification received

by the other party that strict performance will be required of any term

waived, unless the retraction would be unjust in view of a material

change of position in reliance on the waiver.