Property Tax Appeal Deadlines: Cook County 2025 and Texas 2026
Missing a property tax appeal deadline — called a "protest" deadline in Texas — means losing your chance to lower your bill for that entire year. This page covers the Cook County appeal window for 2025 and the Texas protest deadline for 2026. Always verify the exact current date with your county assessor or appraisal district before filing. If you're unsure whether appealing makes sense for your situation, see Should I Appeal Property Tax Assessment.
Cook County Property Tax Appeal Deadline 2025
Cook County, Illinois uses a triennial reassessment schedule — every parcel in the county is reassessed once every three years, on a township-by-township rotation. That matters for deadlines: your appeal window opens when your township's assessment notices are mailed, and it closes roughly 30 days later. If your township was not reassessed this cycle, your window may already be closed for 2025.
The appeal goes first to the Cook County Assessor's Office/CCAO, and if you want a second bite, you can then appeal to the Cook County Board of Review — a separate body with its own filing window, which typically opens after the Assessor closes its period. Townships rotate through the calendar year, so a neighbor in a different township may have a different deadline than you.
To find your current window: look up your township name on your assessment notice, then check the Cook County Assessor's website or the Board of Review's calendar for that township's open dates. Do not rely on a date you read anywhere other than those two official sources — the schedule shifts year to year.
What You Need to File in Cook County
Cook County accepts appeals based on comparable sales (comps), an independent appraisal, or a uniformity argument — meaning similar homes in your area are assessed lower than yours. You'll submit your evidence through the Assessor's online portal or the Board of Review's separate system. Comps should be sales from the same neighborhood, similar square footage, age, and condition, closed within roughly 12 months of the assessment date. The stronger the gap between your assessed value and what the comps suggest, the better your position.
Texas Property Tax Protest Deadline 2026
Texas uses a different system entirely. Your local appraisal district sets your property value each year, and you protest that value before your county's Appraisal Review Board/ARB. The protest deadline in most Texas counties falls on May 15, or 30 days after the appraisal district mailed your Notice of Appraised Value — whichever is later. For the 2026 tax year, watch for your notice in spring 2026 and act quickly once it arrives.
A few Texas counties have slightly different administrative timelines, so treat May 15 as a starting point. Confirm the exact deadline with your appraisal district as soon as your notice arrives — filing late almost always forfeits your right to protest for that year.
How the Texas ARB Process Works
Once you file your protest, the appraisal district typically offers an informal meeting first — a chance to present evidence and reach an agreement before a formal ARB hearing. If no settlement is reached, the ARB hears both sides and rules. Strong comparable sales data gives you the best shot at a reduction, though outcomes vary by county and evidence quality.
Don't Skip the Decision Before the Deadline
Before you file, check whether your assessed value is actually out of line with recent comparable sales. If it already tracks those sales, filing probably won't move the needle. See Should I Appeal Property Tax Assessment for a quick pre-deadline evaluation.
Key Reminders for Both Jurisdictions
- Deadlines are firm. Missing the window almost always ends your appeal or protest right for that tax year.
- Always verify with the official source — the Cook County Assessor, Board of Review, or your Texas appraisal district — not a third-party site.
- In Cook County, your township determines your window; in Texas, your notice date determines yours.
- Filing is free in both jurisdictions when you do it yourself. No company or consultant is required.
- Evidence matters more than paperwork. Strong comps — recent, nearby, similar homes — are the foundation of a successful appeal or protest.
To see where Illinois and Texas rank nationally on property tax burden, visit States With Lower Property Taxes.