Oregon Revised Statutes Occupations and Professions § 697.105

(1) Except as provided in ORS 1.202 and 293.231, if a public body, as defined in ORS 174.109, uses a private collection agency to collect a debt owed to the public body, the public body may add a reasonable fee to the amount of the debt, payable by the debtor, to compensate the public body, in whole or in part, for the collection agency fee incurred or to be incurred.

(2) A fee may not be added under subsection (1) of this section unless the public body has provided notice to the debtor:

(3) Except as provided by federal law, the public body may not add a fee under this section that exceeds the collection fee of the private collection agency.