McHenry County homeowners should start with the property record, then decide whether the assessment is supportable.
The McHenry County Office of Assessments publishes Board of Review rules and points homeowners to county assessment values and property inquiry tools. That is the right starting point because a strong appeal usually begins with the facts already in the county record.
What the Board of Review does
The county Board of Review handles assessment complaints under county rules. Those rules change by assessment year, so homeowners should use the current year's packet and instructions instead of copying an old form from a prior appeal.
The county also provides ways to view submitted complaints and assessor responses. That matters because an appeal is not just what the homeowner says. It is also how the township assessor responds to the evidence.
Talk to the township assessor, but watch the deadline
As with other Illinois counties, the township assessor is usually the first conversation. The assessor may explain the value, correct a property-record issue, or point out what evidence would matter.
But a conversation does not automatically preserve appeal rights. If the Board of Review deadline is approaching, homeowners should not assume an informal discussion extends the filing window.
Evidence that usually matters
McHenry County homeowners should think in three lanes:
- Market value: recent comparable sales, closing statements, or appraisals.
- Uniformity: similar properties assessed differently.
- Property data or condition: photos, repair estimates, permits, or record corrections.
The cleaner the evidence, the easier it is to understand the requested change. A long complaint with weak comparisons is usually less useful than a short complaint with strong comps.
Censum county data snapshot
Censum's Illinois parcel database currently includes **149,981 McHenry County parcel rows**.
That is a meaningful county base for McHenry-specific appeal guidance, comparable selection, and data-backed screening as Censum expands beyond the Cook County launch lane.
Source links
- McHenry County Board of Review
- Illinois Department of Revenue assessment appeal guidance
- Illinois Property Tax Appeal Board service page
Censum note
Censum is building these Illinois county guides so homeowners can understand whether the appeal is a value problem, an evidence problem, or a deadline problem before paying someone a percentage of savings.