Wash. Rev. Code § 36.18.190
Superior court clerks may contract with collection agencies under chapter 19.16 RCW or may use county collection services for the collection of unpaid court-ordered legal financial obligations as enumerated in RCW 9.94A.030 that are ordered pursuant to a felony or misdemeanor conviction and of unpaid financial obligations imposed under Title 13 RCW. The costs for the agencies or county services shall be paid by the debtor. The superior court may, at sentencing or at any time within ten years, assess as court costs the moneys paid for remuneration for services or charges paid to collection agencies or for collection services. By agreement, clerks may authorize collection agencies to retain all or any portion of the interest collected on these accounts. Collection may not be initiated with respect to a criminal offender who is under the supervision of the department of corrections without the prior agreement of the department. Superior court clerks are encouraged to initiate collection action with respect to a criminal offender who is under the supervision of the department of corrections, with the department's approval.
Any contract with a collection agency shall be awarded only after competitive bidding. Factors that a court clerk shall consider in awarding a collection contract include but are not limited to:
The servicing of an unpaid court obligation does not constitute assignment of a debt, and no contract with a collection agency may remove the court's control over unpaid obligations owed to the court.
The county clerk may collect civil judgments where the county is the creditor.
RCW 36.18.190