HRS §490:2-209
Changing or canceling a contract and giving up rights
This section explains how parties can change or cancel a contract. A change does not need something extra in return to be valid. If the contract says changes must be in writing, that rule must be followed, except in some cases. A failed attempt to change a contract may still count as giving up a right, but that can be withdrawn in certain situations.
buyers
The statute, as written — Modification, rescission, and waiver
(1) An agreement modifying a contract within this article needs no consideration to be binding. (2) A signed agreement that excludes modification or rescission except by a signed writing or other signed record shall not be otherwise modified or rescinded, but except as between merchants this type of requirement on a form supplied by the merchant shall be separately signed by the other party. (3) The requirements of the statute of frauds section of this article (section 490:2-201) 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.
Sections this one refers to
§490:2-201 When a written contract is required for a sale of goods
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