RCW 19.36.110: Enforceability of credit agreements—Effect of oral agreements and partial performance.

A credit agreement is not enforceable against the creditor unless the agreement is in writing and signed by the creditor. The rights and obligations of the parties to a credit agreement shall be determined solely from the written agreement, and any prior or contemporaneous oral agreements between the parties are superseded by, merged into, and may not vary the credit agreement. Partial performance of a credit agreement does not remove the agreement from the operation of this section.