Every shop owner on Green Bay Road, every homeowner in Winnetka, and every landlord on Park Avenue in Glencoe will wait two extra months for their second installment property tax bill this year.

Cook County Board President Toni Preckwinkle confirmed in June that second installment bills, normally mailed in July and due Aug. 1, will instead be mailed in September with a due date the county estimated at around Wednesday, Oct. 1. The delay compounds an already painful reality for New Trier Township: these bills will be the first to fully reflect the 39% assessed value increase that Cook County Assessor Fritz Kaegi released in April 2025.

A 39% jump in assessed value does not mean a 39% jump in the tax bill. Final bills depend on the tax rate set by the Cook County Clerk, which has not yet been determined. But for property owners across Glencoe, Winnetka, Wilmette, Kenilworth, and Northfield, the combination of higher assessments and a delayed due date creates a cash-flow crunch that hits in October instead of August.

What it means for North Shore businesses

Commercial property owners along Green Bay Road, Park Avenue in Glencoe, Waukegan Road in Northfield, and the Wilmette business district near the Metra station face compressed planning timelines. Bills reflecting the new assessments will land just weeks before year-end expenses.

To ease the strain on local governments that depend on property tax revenue, Preckwinkle announced $300 million in no-interest bridge loans for school districts, libraries, and park districts. Applications opened July 20. Cook County school districts estimated last year's delays cost them more than $120 million in borrowing and workaround expenses, according to testimony at a Wednesday, June 10 county board hearing.

Why the delay

Last year's second installment was pushed to Dec. 15, 2025, after a botched migration to a new computer system built by Texas-based Tyler Technologies. That system is now functioning, according to multiple county officials who testified at the June 10 hearing, but the cascading effect of last year's problems knocked the entire billing cycle off track.

"On time meaning August 1? Virtually — not, not going to happen," David Byrnes, chief of staff to Cook County Treasurer Maria Pappas, told a county board hearing in April.

At the June 10 hearing, officials could not guarantee even the September mailing deadline. The property tax process was roughly six weeks behind schedule, with data just sent to the Illinois Department of Revenue for a handoff that takes about 60 days before bills are ready to mail.

What residents can do now

Check for missing exemptions. Homeowners who were eligible for a homestead, senior, senior freeze, or disability exemption in tax years 2021 through 2024 but never received it can apply for a Certificate of Error through the Cook County Assessor's Office. Applications are processed in eight to 10 weeks, with refund checks mailed three to four weeks after approval. Apply online at cookcountyassessoril.gov/certificates-error or mail forms to 118 North Clark St., Room 320, Chicago, IL 60602.

Budget with the "Rule of 12s." County officials urge property owners to set aside one-twelfth of their anticipated annual tax bill each month so the money is available whenever the bill arrives. For a North Shore homeowner or small business owner, that monthly discipline matters whether the bill comes in August or October.

Look up your property. Because the final tax rate has not been set, no specific bill amount is available yet. Residents can check their assessed value at cookcountyassessor.com or call 847-448-8168 with questions about assessments, exemptions, or appeals.

Bills are expected to be mailed in September and due around Wednesday, Oct. 1. County officials could not guarantee that timeline as of June 10.