Worth and Leyden Property Tax Appeals: 2026 Deadlines

As of September 7, 2026, the Cook County Assessor is accepting assessment appeals for Leyden Township through Wednesday, October 14, and for Worth Township through Thursday, October 15. These are Assessor filing windows for the 2026 assessment year. They are separate from any later Cook County Board of Review period.

Before relying on a date, confirm the township tied to the property’s PIN and check the Younis Law Group Cook County deadline tracker. The tracker identifies the appeal body and links each record to the government source.

What are the Worth and Leyden appeal deadlines?

Leyden Township’s Assessor window opened August 31 and closes October 14, 2026. Worth Township’s window opened September 1 and closes October 15, 2026. The Assessor’s calendar was last updated September 4 and lists both townships as open.

A municipality name is not enough to establish the deadline. Leyden Township includes several communities near O’Hare and the west suburbs, while Worth Township covers a broad southwest-suburban area. Use the Cook County property search and the property’s permanent index number, or PIN, to verify the township before filing.

What must be submitted by the closing date?

The Assessor’s 2026 rules call the township closing date a hard deadline. The appeal and all supporting documentation must be filed by that date. The office says late material will not be accepted except when a documented Assessor system error prevented filing.

A timely form without meaningful evidence may preserve less than an owner expects. The submission should identify the estimated fair market value being requested and explain why the current assessment is unsupported. Useful evidence depends on the property and the theory of the appeal.

What evidence should a homeowner gather?

Start with the reassessment notice, current property record, PIN, recent photographs, and any documents showing that the Assessor’s description is wrong. For an overvaluation argument, a recent arm’s-length sale or well-matched sales may be relevant. For a lack-of-uniformity argument, compare the assessed value of genuinely similar properties rather than simply choosing the lowest assessments nearby.

Keep assessed value separate from the final tax bill. An assessment appeal asks whether the property’s valuation or classification is correct. Exemptions, equalization, local tax rates, and levies also affect the bill, so a lower assessment does not translate into a guaranteed dollar result.

What should a commercial owner prepare?

Commercial and larger multifamily filings often require a property summary, photographs, current income and expense information, rent rolls, vacancy support, sales documents, or an appraisal when warranted. The Assessor’s forms and rules control the required material for each argument. Organize the documents around one supported valuation conclusion instead of uploading disconnected records.

What if the Assessor deadline is missed?

Do not assume the assessment can no longer be reviewed. The Cook County Board of Review uses a separate township calendar and may provide a later opportunity. That later window should be confirmed from the Board’s official schedule; it is not an extension of the Assessor deadline, and its rules and evidence requirements differ.

What is the next step before October 14 or 15?

Confirm the township, identify the valuation issue, and assemble the evidence early enough to correct a filing problem. Owners who want help can review Younis Law Group’s Cook County property tax appeal service and request a case review before the applicable deadline.

Official sources: Cook County Assessor calendar and Assessor’s 2026 appeal rules.

This article provides general information, not legal advice. Filing dates and requirements can change; verify the current Assessor calendar and rules before submitting an appeal.