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Is Cook County over-assessing your home?

See where your assessed value lands against comparable nearby homes.

Plain math on Cook County's own public records — no signup, no credit card. If you're fairly assessed, we'll tell you.

  • ✓Estimated annual + 3-year overpayment in dollars
  • ✓Your assessed value vs. 3 nearby comps
  • ✓Your assessment level vs. similar nearby homes and Cook County's 10% residential target
  • ✓Your township's appeal window status
What your check returnsSample
1234 S Sample Ave · Lyons Township · synthetic sample
Estimated annual overpayment
$1,420/yr
Your assessed value$42,500
Avg of 3 nearby comps$35,100
Assessment gap+$7,400 (21%)
Assessment level12.1% vs. 10% residential target
Illustrative figures. Your real check runs against Cook County public records — no signup, no card. We do not guarantee a reduction.
Free Check · No signup
Start your free check
Real Cook County public-record lookup·No signup · no credit card
If you're fairly assessed, we'll tell you. No upsell.
○Procedural refund policy if your township denies the filing on procedural grounds
Cook County · 2024–2026 cycle

Cook County residential assessments are tested against a 10% level — and uniformity with comparable homes.

For class 2 residential property, assessed value is generally targeted at 10% of market value. Appeals also depend on uniformity: whether comparable homes are assessed lower than yours.

10% target6%8%10%12%14%Assessment level across Cook County properties
Illustrative distribution based on public Cook County assessment records. Treat this as methodology context, not a claim about your property or a guaranteed appeal outcome.
What you'll get

A one-page report — the only thing the Board of Review actually reads.

Your assessed value, three nearby comps, your assessment level against Cook County's 10% residential target, and the uniformity gap vs. similar homes. Every number is sourced from public CCAO records you can verify yourself.

  • Estimated annual + 3-year overpayment in dollars
  • 3 nearby comps, picked from your neighborhood code
  • Assessment level + uniformity gap vs. Cook County's 10% residential target and nearby comps
  • Township appeal window with the close date
SampleLyons Twp
Your free check · sample
1234 S Sample Ave, La Grange IL 60526
Synthetic sample PIN · Lyons Township
Estimated annual overpayment
$1,420/yr
≈ $4,260 over the 3-year cycle
Your assessed value
$42,500
123 Sample Ave
$36,400
127 Sample Ave
$34,800
131 Sample Ave
$34,100
Assessment level12.1%
Target 10.0%
Over-assessed by 2.1 percentage points
Lyons Township appeal window open through Jun 9, 2026
Data
Cook County Assessor + Board of Review public records, checked regularly
Method
We compare residential assessment level and comp uniformity, not black-box averages
Scope
All 38 Cook County townships · schedule links are public-record backed
How we estimate your overpayment

Plain math on public records — not a black box.

Cook County publishes every assessment, every comparable, and every appeal outcome. We use that data — the same data the Board of Review uses — to tell you whether your number is out of line.

  1. 01

    Pull your record

    Your PIN returns your assessed value, market value, square footage, year built, and property class — straight from CCAO records.

  2. 02

    Find three comparables

    We search your neighborhood code for properties of similar size, age, and class — the same logic the Board of Review applies to comparable-sales appeals.

  3. 03

    Check level and uniformity

    For class 2 residential property, Cook County targets an assessed value near 10% of market value. We separately compare your assessment level with similar nearby homes so the appeal argument is about both statutory level and uniformity.

  4. 04

    Estimate the overpayment

    Gap × your township's effective tax rate × the 3-year triennial window. The arithmetic is shown on your result page — copy it into your appeal verbatim.

We don't publish countywide savings averages or success-rate claims until we have verified, named Cook County outcomes. Our first customer wins are being filed in the 2026 cycle — we'll show them here, by name and township, when the Board of Review rules.
Outcomes

Verified Cook County outcomes will publish after 2026 Board decisions.

We don't publish testimonials or savings averages we haven't verified. Until the first 2026 decisions come back, review the actual deliverable instead: a Cook County-ready appeal packet with comps, assessment-level analysis, filing instructions, and deadline tracking.

See what the packet includes →View sample report
Three ways to file

Same outcome. Pick flat-fee help or contingency review.

Recommended
DIY Appeal Packet
$69one-time · keep 100% of your savings

Everything you need to file the appeal yourself in your township.

  • ✓Pre-written appeal argumentTailored to assessment level + comp uniformity
  • ✓3 nearby comparablesFormatted for Board of Review
  • ✓Step-by-step filing instructionsSpecific to your township
  • ✓Deadline reminders2026 window + 2027 second pass
  • —We submit on your behalfYou file yourself (~15 min)
Get the DIY Packet→
Done-For-You
$97one-time · we file and follow up

We prepare and submit the appeal — you just sign the authorization.

  • ✓Pre-written appeal argumentTailored to assessment level + comp uniformity
  • ✓3 nearby comparablesFormatted for Board of Review
  • ✓Step-by-step filing instructionsOr skip — we file for you
  • ✓Deadline reminders2026 window + 2027 second pass
  • ✓We submit on your behalfTracked through BoR decision
Choose Done-For-You→
No upfront fee
Contingency
22%of first-year savings · only if granted

For larger potential reductions: no upfront service fee, reviewed before acceptance.

  • ✓Pre-written appeal argumentBuilt after case review
  • ✓3 nearby comparablesFormatted for Board of Review
  • —Step-by-step filing instructionsWe handle accepted cases
  • ✓Deadline remindersTracked through decision
  • ✓We submit on your behalfAfter explicit authorization
Request contingency review→
○Procedural refund policy if your township denies the filing on procedural grounds
HOA & condo associations

Managing many PINs? We'll build a bulk packet for your association.

Condo boards and HOA managers in Cook County can use the same comparable-property + assessment-level packet, run across every PIN in the association. No legal-representation claim, no per-unit upsell. Drop your email and one OverTaxed IL contact will reply within 2 business days with the next-step plan.

OverTaxed IL is not a law firm and does not provide legal advice. We do not guarantee a reduction — county decisions are final.

Common questions

Frequently asked questions.

  • Each Cook County township has its own appeal window. The county runs on a rolling 3-year triennial cycle, and only about a third of townships are open at any given time. Once you enter your address, we show your specific township's window and exact close date. The 2026 triennial covers the South and West Suburbs first; North Suburbs and the City of Chicago follow in 2027 and 2028.

  • You'll see your full report on the next screen — assessed value vs. comparable properties, assessment-level gap, estimated annual and 3-year overpayment, and your township's appeal window status. No signup, no credit card. If your check shows over-assessment, you can pick the DIY Appeal Packet ($69), Done-For-You ($97), or request contingency review for larger cases. If your numbers don't suggest an appeal, we'll tell you that too.

  • Cook County Assessor and Board of Review public records. We check township schedules regularly and avoid publishing outcome claims until they are verified. It's the same public-record base the Board of Review uses to decide appeals.

  • Cook County doesn't penalize you for filing — you keep the assessed value on file. The $69 DIY packet is a flat service fee for preparing your appeal materials and is paid regardless of outcome. A refund applies only if an OverTaxed IL procedural error causes the county to reject the filing.

  • Most homeowners pick the $69 DIY Appeal Packet when they want us to build the comp package and they are comfortable filing it themselves. Done-For-You at $97 is for homeowners who want us to submit after they sign explicit filing authorization.

  • No. OverTaxed IL is not a law firm and does not provide legal advice. We help you organize public records into the format the Board of Review accepts.

● OverTaxed IL
Cook County property tax appeals, built for homeowners.
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OverTaxed IL is not a law firm and does not provide legal advice. Estimates are based on public Cook County Assessor records and may vary from final Board of Review outcomes.

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