A Rock Island County owner challenges an assessment by filing a written complaint with the county Board of Review during the short period that begins when assessment changes are published. The county describes a 30-day filing window and makes complaint forms available when publication occurs. As of July 16, 2026, the Board page still repeated the prior year's October 28 close and did not identify a 2026 publication date. That old date is not a usable deadline. Owners should monitor the official Board page, contact the office, and preserve the publication or notice that establishes the current window. FairPath can organize a manual evidence record and official links, but it does not submit the complaint, choose a requested value, represent the owner, or claim automated Rock Island coverage.
Assessment context: Rock Island County's Board acts on assessed value, not the amount of the tax bill. Start by checking the parcel number, township or assessment district, land value, improvement value, property class, living area, age, construction, basement, lot, and condition on the official record. Illinois generally assesses non-farm property at one-third of fair cash value, subject to equalization, but the individual argument still needs property-specific support. The county includes older urban housing in Rock Island and Moline, river-adjacent influences, industrial corridors, smaller communities, rural parcels, and newer subdivisions. A sale or assessment from another part of the county may not reflect the same market. Separate factual record errors, market-value evidence, and unequal-assessment evidence so the Board can understand the exact issue presented.
Filing process: The county's seven-step guidance begins with obtaining the assessed valuation, estimating fair market value, and discussing the record with the township assessor before filing. That discussion does not replace a timely formal complaint. When the county publishes assessments, download the current complaint form and Board rules, verify the closing date, complete every parcel and ownership field, state the requested assessment, and attach the evidence required by the current instructions. Keep proof showing when and how the Board received the filing. If a hearing is scheduled, follow the notice for attendance, exhibit exchange, and any copy requirements. A dissatisfied owner may have a later route to the Illinois Property Tax Appeal Board, but that is a separate filing with its own deadline. FairPath's page supports preparation only; the owner remains responsible for every submission and confirmation.
Evidence to review: A useful Rock Island residential file connects each exhibit to a valuation or uniformity issue. For market value, record recent arm's-length sales with parcel numbers, dates, prices, locations, building style, living area, age, lot, basement, garage, condition, and unusual transaction facts. For assessment uniformity, compare current assessed values and physical characteristics of genuinely similar nearby parcels in the same assessment context. Dated photographs, inspection reports, permits, contractor scopes, and repair estimates can document deferred maintenance or a record discrepancy, but repair cost is not automatically a dollar-for-dollar value adjustment. The Board's rules indicate that a complaint can lead it to review the entire assessment, not only the component identified by the owner. Verify all figures against official records, label exhibits, explain material differences, and retain the exact packet presented.
Current deadline guidance: Thirty days after the 2026 assessment publication date; the county has not yet posted a closing date. Rock Island County opens its formal complaint session when assessment changes are published in the local newspaper. An owner then has 30 days to file. The county page still displayed the prior October 28, 2025 close when reviewed July 16, 2026, so owners must confirm the 2026 publication and deadline directly with the Board of Review rather than reuse that date.
Rock Island's filing window is triggered by newspaper publication rather than a fixed statewide calendar date. The 2026 close must be confirmed after publication; the stale 2025 banner is not controlling.
The Board is the final local assessment-review authority and addresses assessed value rather than dissatisfaction with tax rates, exemptions, or the total bill.
The county's urban, river, industrial, rural, and suburban property contexts require a location explanation for every selected comparable.
Rock Island encourages discussion with the local assessor first, but informal contact does not preserve the 30-day Board deadline.
Official filing authority: Rock Island County Board of Review. https://www.rockislandcountyil.gov/180/Appealing-an-Assessment
Source: Rock Island County Government, Board of Review Office and Complaint Window, https://rockislandcountyil.gov/175/Board-of-Review-Office. Reviewed 2026-07-16.
Source: Rock Island County Government, Appealing an Assessment: Seven Steps, https://www.rockislandcountyil.gov/180/Appealing-an-Assessment. Reviewed 2026-07-16.
Source: Rock Island County Government, Rock Island County Board of Review Rules, https://www.rockislandcountyil.gov/181/Board-of-Review-Rules-PDF. Reviewed 2026-07-16.
Source: Illinois Department of Revenue, Assessment Appeals - Property Tax, https://tax.illinois.gov/localgovernments/property/appeals.html. Reviewed 2026-07-16.