Cook County · Illinois
Proviso Township property tax appeals
A Proviso Township property tax appeal starts with the Cook County Assessor's Office, then the Cook County Board of Review. The next deadline is Oct 27, 2026 for Proviso Township, Cook County Assessor's Office.
- Next deadline
- Oct 27, 2026
- Open now
- Proviso Township · Cook County Assessor's Office
Opens Sep 14, 2026Closes Oct 27, 2026
- Source: Assessment & Appeal Calendar (page last updated 9/22/26) - Cook County Assessor's OfficeLast checked
Check a Proviso Township home for free
Enter the address or parcel number from your notice. We compare the assessment with similar homes and show the numbers, whatever they are. You decide and file yourself.
Part of Cook CountyEvery appeal date in Cook County
- Where to file first
- Cook County Assessor's Office
- Our coverage
- Free check available
- Independent guide — not affiliated with Proviso, Cook County or any government agency.
When and where do I file a Proviso Township property tax appeal?
Who hears a Proviso Township appeal?
The stages in order. We are not affiliated with any of these offices.
Cook County Assessor's Office
Cook County Board of Review
Circuit Court of Cook County (tax objection)
Illinois Property Tax Appeal Board
Which Proviso Township filing windows are coming up?
| Closes | Area | Who hears it | Status |
|---|---|---|---|
| Oct 27, 2026 | Proviso Township | Cook County Assessor's Office | Open now |
When were past Proviso Township deadlines?
| Tax year | Window | Office |
|---|---|---|
| 2023 | Closed October 30, 2023 | Proviso · Cook County Assessor's Office |
When is the Proviso appeal deadline?
Cook County Assessor's Office: Closes October 27, 2026.
- Deadline detailBoard of Review re-review
- Proviso Township, tax year 2025: the Board of Review's decision date was Apr 13, 2026 and the re-review period closed Apr 15, 2026; the Assessor (CCAO) certification date was May 11, 2026.[1]
- Deadline detailNotice mailed
- Proviso Township (2026 reassessment): Reassessment Notices were mailed Sep 14, 2026; appeals were due Oct 27, 2026.[2]
Who can answer questions about my assessment?
Hours: Proviso Township Assessor's office hours: 9:00 A.M. to 4:00 P.M. Office: The Proviso Township Assessor's office is at 4565 Harrison Hillside, IL 60162; phone (708) 449-4304.
What do Proviso Township property taxes and assessments look like?
Figures from public records and the Census, each with its source. They describe the county's homes as a group, not the value of any one home.
How Proviso Township home assessments are spread
Proviso Township compared with other townships
- Hanover$31,000
- Leyden$30,000
- West Chicago$30,000
- Berwyn$25,000
- Proviso$24,000
- Stickney$23,000
- Worth$23,000
- Cicero$22,000
- Rich$20,000
Ranked 28 of 38; showing the 9 nearest in rank.
Median assessed value by township: highest North Chicago ($135,400), lowest Thornton ($12,000).
What happened to Proviso Township appeals in tax year 2025
- Assessor11% lowered of 3,899
- Board of Review44% lowered of 6,233
Assessor: 11% of 3,899 appeals lowered (median cut 6.2%); Board of Review: 44% of 6,233 appeals lowered (median cut 7.7%)
Proviso Township filing windows on a calendar
- Proviso TownshipOct 27, 2026 · Cook County Assessor's Office · Open now
The dashed line marks today.
Proviso Township: Oct 27, 2026
How often is property reassessed in Proviso?
Proviso Township is reassessed every three years with the South and West Suburbs; its scheduled reassessment years are 2026, 2029 and 2032.
- Reassessment cycle
- Proviso Township is reassessed every three years with the South and West Suburbs; its scheduled reassessment years are 2026, 2029 and 2032.[3]
What do home values and property taxes look like in Proviso?
Proviso Township (2026 reassessment): the Assessor's median estimated market value for single-family homes was $286,000 (median 2025 sale price $326,000). Proviso Township (2026 reassessment): condos had a median 2025 sale price of $155,000; the Assessor's median estimate was $172,000.
- Median assessor estimate
- Proviso Township (2026 reassessment): the Assessor's median estimated market value for single-family homes was $286,000 (median 2025 sale price $326,000).[2]
- Median condo price
- Proviso Township (2026 reassessment): condos had a median 2025 sale price of $155,000; the Assessor's median estimate was $172,000.[2]
- Median sale price
- Proviso Township (2023 reassessment): the median sale price of single-family homes in 2022 was $278,000; the Assessor's median market value estimate for the class was $240,000.[4]
- Median small apartment price
- Proviso Township (2026 reassessment): small apartment buildings had a median 2025 sale price of $449,000; the Assessor's median estimate was $379,000.[2]
Other places nearby
- Palos TownshipFree check available
- Rich TownshipFree check available
- River Forest TownshipFree check available
- Orland TownshipFree check available
- Riverside TownshipFree check available
- Oak Park TownshipFree check available
Where do these facts come from?
- [1]Board of Review 2025 Re-Review/Decision Dates (PDF, Rev.6/9/2026) - Cook County Board of ReviewOfficial notice, form, calendar or rules · last checked Oct 1, 2026
- [2]Proviso: Residential Valuations - Cook County Assessor's OfficeOfficial guide or FAQ · last checked Oct 1, 2026
- [3]Township Triennial Reassessment Schedule (PDF) - Cook County Board of ReviewOfficial notice, form, calendar or rules · last checked Oct 1, 2026
- [4]Property Values for Proviso Township Released - Cook County Assessor's Office (press release, October 9, 2023)Official guide or FAQ · last checked Oct 1, 2026
- [5]Cook County Township Assessors - Cook County Assessor's OfficeOfficial guide or FAQ · last checked Oct 1, 2026
- [6]Assessment & Appeal Calendar (page last updated 9/22/26) - Cook County Assessor's OfficeOfficial notice, form, calendar or rules · last checked Sep 24, 2026
- [7]35 ILCS 200/12-55 - Illinois Property Tax Code (ILGA; Wayback capture 2026-01-09)Statute or regulation · last checked Sep 24, 2026
- 8.County open data: cook assessmentsRetrieved Sep 25, 2026; aggregated by us for the charts above.
- 9.County open data: cook parcelsRetrieved Sep 25, 2026; aggregated by us for the charts above.
- 10.County open data: cook parcelsRetrieved Sep 25, 2026; aggregated by us for the charts above.
- 11.County open data: cook parcelsRetrieved Sep 25, 2026; aggregated by us for the charts above.
- 12.County open data: appeal resultsAggregated by us for the appeal-results chart.
- 13.County open data: appeal resultsAggregated by us for the appeal-results chart.
Not affiliated with Proviso Township or any government agency. Not legal advice. Not an appraisal.