Oregon Revised Statutes Occupations and Professions § 673.690

(1) Except as provided in this section, every person licensed as a tax consultant shall keep records of all personal income tax returns prepared by the person, or in the preparation of which advice or assistance of the person has been given. The records of the returns shall be kept for a period of not less than four years after the date of the preparation, advice or assistance.

(2) If a tax consultant is employed by another tax consultant, the records shall be kept by the employing tax consultant.

(3) If a tax consultant who has been designated as responsible for the tax return preparation activities and decisions of a partnership, corporation or other legal entity ceases to be connected with the partnership, corporation or other legal entity, the records shall be retained by the partnership, corporation or other legal entity.