(1) The department may retain, by written contract, collection agencies licensed under chapter 19.16 RCW or licensed under the laws of another state or the District of Columbia for the purpose of collecting from sources outside the state of Washington taxes including interest and penalties thereon imposed under this title and RCW 84.33.041.

(2) Only accounts represented by tax warrants filed in the superior court of a county in the state as provided by RCW 82.32.210 may be assigned to a collection agency, and no such assignment may be made unless the department has previously notified or has attempted to notify the taxpayer of his or her right to petition for correction of assessment within the time provided and in accordance with the procedures set forth in chapter 82.32 RCW.

(3) Collection agencies assigned accounts for collection under this section shall have only those remedies and powers that would be available to them as assignees of private creditors. However, nothing in this section limits the right to enforce the liability for taxes lawfully imposed under the laws of this state in the courts of another state or the District of Columbia as provided by the laws of such jurisdictions and RCW 4.24.140 and 4.24.150.

(4) The account of the taxpayer shall be credited with the amounts collected by a collection agency before reduction for reasonable collection costs, including attorneys fees, that the department is authorized to negotiate on a contingent fee or other basis.