Property Assessment Appeals in Stephenson County, Illinois
Stephenson County uses a publication-triggered complaint calendar rather than a single safely reusable annual date. The posted Board rules say a fully completed complaint is due on or before the 10th day of September (September 10, 2026 has passed), or on or before 30 calendar days after the date of publication of the current year assessment list. For the 2025 assessment year, the county's township publication notices listed a complaint deadline of January 2, 2026. As of October 18, 2026, the county's Assessment Office page links those 2025 publications, and no 2026 township publication was found, so the sources reviewed do not establish a 2026 township deadline. The Board of Review clerk can confirm whether a 2026 window applies to a particular township. The FairPath owner-guided evidence packet is available now for Stephenson County properties and can organize the parcel record, owner corrections, recent sales, equity comparisons, photographs, and Board rules. FairPath does not file the complaint, appear at the hearing, or turn an unconfirmed publication date into a filing promise.
Assessment context: Stephenson's process begins with the township assessor or Chief County Assessment Officer, not the Treasurer's tax-bill office. The county directs Freeport Township parcels, whose PIN begins with 18, to the Freeport Township Assessor and lists other local assessment officials separately. Illinois generally assesses non-farm property at one-third of fair cash value as of January 1, subject to equalization. Review the online property record for the PIN, land and improvement values, property class, building characteristics, exemptions, and recent assessment changes. Then separate possible grounds: a recent arm's-length sale, overvaluation shown by comparable sales or appraisal, unequal treatment relative to similar property, a physical-data discrepancy, or a legal or preferential-assessment issue. A higher tax bill, a tax-rate change, or the percentage increase alone is not a valuation ground before the Board.
Filing process: The Board rules encourage discussing the record with the responsible township assessor or Chief County Assessment Officer before filing and state that, by state law, the complaint period cannot be extended during that discussion. For a residential parcel, the county's Forms and Publications page lists the BOR-R-1 form, and the rules address signatures, PINs, requested assessment, selected grounds, copies, and evidence. The posted rules reject faxed and emailed complaints. Hand-delivered material is filed when received. United States mail can use the official cancellation mark, but metered mail arriving late also needs a United States Postal Service date stamp; private carriers do not receive that postmark treatment. The Board requires all contiguous parcels with common ownership and use to be included and permits one form plus an addendum for a qualifying multi-PIN property. An incomplete filing can be returned and must still be corrected before the deadline.
Evidence to review: Stephenson's rules generally require the owner's full evidence packet at filing. A documented appraisal may arrive up to 15 calendar days after the filing deadline, but the Board treats other late evidence differently. For overvaluation, identify recent similar nearby sales and show sale date, price, PIN, property record, exterior area, lot, age, style, condition, and adjustments. For equity, compare assessment treatment among genuinely similar neighborhood properties rather than substituting market sales for an assessment-uniformity claim. For a physical-data discrepancy, provide clear color photographs, measurements, permits, inspection material, or other records that establish the error. The rules require disclosure of a recent subject sale and, for recent construction, construction costs and permits. They also call for two copies of documents other than the complaint and impose extra-copy obligations when the requested assessed-value reduction is at least $50,000.
Current deadline guidance: Board rule: Sept 10, 2026 (passed) or 30 days after the assessment list is published; no 2026 publication found. Stephenson County's posted Board rules (2025 edition) state that fully completed complaints must be filed with the Clerk of the Board on or before the 10th day of September (September 10, 2026 has passed), or on or before 30 calendar days after the date of publication of the current year assessment list (35 ILCS 200/16-55). For the 2025 assessment year, the county's township publication notices listed a complaint deadline of January 2, 2026. As of October 18, 2026, the county's Assessment Office page links those 2025 publications, and neither a 2026 township publication nor a 2026-specific Board of Review Rules document was found (the Board of Review page links only the 2025 edition). The sources reviewed do not show which date controls for a 2026 parcel; the township's publication notice and the Board of Review clerk are the places to confirm a township's status.
Stephenson's Board rules tie the complaint deadline to assessment-list publication: September 10 (the 2026 date has passed), or 30 calendar days after the current year's list is published. The county's 2025 township notices listed January 2, 2026; as of October 18, 2026, no 2026 publication was found on its Assessment Office page, so the Board of Review clerk is the source for a 2026 township's date.
Freeport Township parcels are identified by PINs beginning with 18 and are directed to the Freeport Township Assessor, while the county office supports the remaining township assessment structure.
The Board rejects faxed and emailed complaints and distinguishes an official United States Postal Service postmark from private-carrier delivery or unsupported metered mail.
Stephenson generally requires evidence with the original complaint, two copies of supporting documents, recent-sale disclosure, and additional copies for a requested assessed-value reduction of at least $50,000.
Official filing authority: Stephenson County Board of Review. https://stephensoncountyil.gov/departments/county_assessment_office/forms___publications/index.php
Source: Stephenson County, Illinois, County Assessment Office, https://stephensoncountyil.gov/departments/county_assessment_office/index.php. Reviewed 2026-10-18.
Source: Stephenson County, Illinois, Board of Review, https://stephensoncountyil.gov/departments/county_assessment_office/board_of_review/index.php. Reviewed 2026-10-18.
Source: Stephenson County Board of Review, 2025 Stephenson County Board of Review Rules, https://stephensoncountyil.gov/Document_Center/Department/County%20Assessment%20Office/2025%20Stephenson%20County%20Board%20of%20Review%20Rules.pdf. Reviewed 2026-10-18.
Source: Stephenson County Chief County Assessment Office, Assessment Complaint Forms and Publications, https://stephensoncountyil.gov/departments/county_assessment_office/forms___publications/index.php. Reviewed 2026-10-18.
Source: Illinois Department of Revenue, Assessment Appeals, https://tax.illinois.gov/localgovernments/property/appeals.html. Reviewed 2026-10-18.
Source: Stephenson County Chief County Assessment Office, 2025 Township Assessment Changes publication (quad-year notice), https://stephensoncountyil.gov/2025%20QUAD%20CHANGES%20PUBLISH.pdf. Reviewed 2026-10-18.
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