If a proposed assessment is sustained, in whole or part by the Office of Hearing and Appeals, the taxpayer may request in writing, within twenty (20) days of the mailing of the decision, that the director revise the decision of the hearing officer. If the director refuses to make a revision, then a final assessment shall be made upon the final determination of the hearing officer.
1.26 Ark. Code R. 18-405(d)(4)(A)