This year’s second-installment property-tax bill — the one that normally arrives in early July and comes due August 1 — now has a due date: October 1, 2026, per the Treasurer’s due-date table, 61 days past the statutory August 1. That makes the fourth late second installment in five billing years, and the mildest of the four: due dates of December 30, 2022 (151 days past the normal date), December 1, 2023 (122 days), December 15, 2025 (136 days), and now October 1, 2026 (61 days), with only the 2024 season’s bill arriving on the statutory schedule. Before this stretch, the county had been on time every year since 2012 — and before that, late every year for more than three decades. Every due date on this page is a date the county or its Treasurer published, and every source is linked in the body or the Sources list at the end of this page.
Cook County Treasurer due-date table + Cook County press releases, each read in full · retrieved August 14, 2026; due-date table re-checked August 17, 2026, when the tax year 2025 second-installment row was presentThe ledger of due dates
- 2021 billing season (tax year 2020)late charges waived to Oct 1Aug 2, 2021on schedule
- 2022 billing season (tax year 2021)Dec 30, 2022151 days past Aug 1
- 2023 billing season (tax year 2022)Dec 1, 2023122 days
- 2024 billing season (tax year 2023)Aug 1, 2024on schedule
- 2025 billing season (tax year 2024)Dec 15, 2025136 days
- 2026 billing season (tax year 2025)Oct 1, 202661 days
One reading rule before anything else: Cook County names these bills two different ways, and its own releases use both. The bill due December 15, 2025 is the tax year 2024 second installment — taxes are billed a year in arrears — but a June 2024 county release calls the bill due December 1, 2023 “the 2023 second installment,” naming it by the year it was paid. This page names every bill both ways. The days-behind figures are our arithmetic against August 1 of the billing year; the dates themselves are the county’s, linked under Sources at the end of this page.
What the county says, in its own words
Announcing the December 15, 2025 due date, the county named its cause: “the critical overhaul of the technological backbone of the Cook County property tax system has had an impact on the County’s property tax processes and timelines.” This June’s announcement of the coming delay did not carry a new date — only that the next round of bills “will be delayed by approximately two months.” Measured from August 1, that estimate pointed at early October. At our August 14 retrieval, the Treasurer’s due-date table listed a tax year 2025 first-installment due date — April 1, 2026 — and no second-installment row at all. By the August 17 re-check, the row was there: Tax Year 2025 Second Installment Property Tax Due Date, Thursday, October 1, 2026 — 61 days past August 1, consistent with the county’s two-month phrase.
The delay has a price the county itself budgets for. Alongside the June announcement, the county said it intends to reopen its Property Tax Bridge Fund — up to $300 million in no-interest loans for school districts, park districts, libraries, fire-protection districts and municipalities that run on property-tax revenue and would otherwise wait months for it. The county calls this the third time it has offered the program in response to billing delays; in the last round, by its own account, nearly 20 taxing districts drew over $20 million.
The decade the bills were on time
Late bills are not new here — they are the older normal. When the 2013 bills went out on schedule, the Civic Federation wrote that between at least tax year 1977 and the bills mailed in 2011, second installments went out late every year, by the account of the county’s own elected officials. The 2012 billing season broke that streak, and the county then stayed on schedule for ten straight years, through the 2021 season — whose bill was due August 2, 2021 (August 1 was a Sunday), with late charges pushed to October 1 by ordinance 20-5643 — a two-month late-fee waiver on both of 2021’s installments that the county board passed in November 2020, announced by the Treasurer with both dates stated. The streak ended with the bill due December 30, 2022, and the county has hit the statutory date once since.
What a late bill changes for you
The amount owed is not what moves — the delay shifts when it is owed, and compresses the gap between payments: the bill due December 15, 2025 was followed by the next first installment on April 1, 2026, about three and a half months later. Suburban governments have been reminding residents what the delay does not change: Evanston’s July notice, for one, tells property owners that not receiving a bill does not exempt them from the deadlines once bills issue. What sits behind each bill’s arithmetic — assessments, appeals, and the two-stage review that precedes billing — is measured in our analyses of the county’s own assessment and appeal records, linked below.
Known limits
No dataset backs this page; published pages do — the county’s and the Treasurer’s for every due date, each linked under Sources below, and the Civic Federation’s account for the pre-2012 record. The October 1, 2026 date is the Treasurer’s published date and, like any published date, could be revised; this page was updated August 17, 2026, when the row appeared on the Treasurer’s table, keeping the promise the first version made. The days-behind figures measure against August 1 of the billing year — the date the county’s own 2024 release treats as the statutory schedule — and the on-time decade is stated as the county and the Civic Federation record it, without re-deriving each year’s mailing date. This page reports the county’s stated cause and offers none of its own.
- Sources Cook County Treasurer, Important Dates (retrieved August 14, 2026; re-checked August 17, 2026, when the tax year 2025 second-installment row was present); Cook County news releases: bills delayed, bridge fund reopened (June 2026), tax year 2024 second installment (2025), second installment due December 1 (2023), and return to the timely schedule (June 2024); Civic Federation (July 2013) on the pre-2012 record; Treasurer’s office (November 24, 2020, stating the August 2, 2021 due date and the October 1, 2021 late-charge date under ordinance 20-5643). Each read in full at retrieval.
- Also read City of Evanston, notice on the expected 2026 delay (July 2026).
- Counting Days behind measure the published due date against August 1 of the billing year, by calendar arithmetic. A bill due on the first business day after August 1 counts as on schedule. Tax-year and billing-year names are both given for every bill because the county’s own materials use both.
Compiled by KCM Desk from the county’s published pages, retrieved August 14, 2026 and updated August 17, 2026 with the announced due date. If you spot an error, corrections come first.