2.5% Supplemental Rollback Phone: (937) 225-4333 · Fax: (937) 496-3202   The 2.5% Supplemental Rollback is a tax reduction program administered by the County Auditor.The program is available to all owner-occupied residential properties in Ohio. Rental properties are not eligible for the reduction. A 2.5% credit based on value is available on a homestead located on property up to one acre in size. Email the Auditor's Office Regarding 2.5% Supplemental Rollback