Wash. Rev. Code § 50A.45.070
The commissioner may compromise any claim for premiums, interest, or penalties due and owing from an employer, and any amount owed by an individual because of benefit overpayments existing or arising under this title in any case where collection of the full amount due and owing, whether reduced to judgment or otherwise, would be against equity and good conscience. Whenever a compromise is made by the commissioner in the case of a claim for premiums, interest, or penalties, whether reduced to judgment or otherwise, there shall be placed on file in the department a statement of the amount of premiums, interest, and penalties imposed by law and claimed due, attorneys' fees and costs, if any, a complete record of the compromise agreement, and the amount actually paid in accordance with the terms of the compromise agreement. Whenever a compromise is made by the commissioner in the case of a claim of a benefit overpayment, whether reduced to judgment or otherwise, there shall be placed on file in the department a statement of the amount of the benefit overpayment, attorneys' fees and costs, if any, a complete record of the compromise agreement, and the amount actually paid in accordance with the terms of the compromise agreement. If any such compromise is accepted by the commissioner, within such time as may be stated in the compromise or agreed to, such compromise shall be final and conclusive and except upon showing of fraud or malfeasance or misrepresentation of a material fact the case shall not be reopened as to the matters agreed upon. In any suit, action, or proceeding, such agreement or any determination, collection, payment, adjustment, refund, or credit made in accordance therewith shall not be annulled, modified, set aside, or disregarded.
RCW 50A.45.070