When the sale is held
No single statewide month. In counties with fewer than 3,000,000 inhabitants the collector must apply for judgment and order of sale within 90 days after the second installment due date, and the sale begins on a date within 5 business days after the application date. In Cook County the application is made within 365 days of the second installment due date, and recent Cook sales have been moved by separate statutory deadlines. Check the county collector page for the current cycle.
When taxes go delinquent
Illinois property taxes are billed in two installments. The first installment is delinquent on the later of June 1 or the day after the due date printed on the bill, and the second installment is delinquent on the later of September 1 or the day after its printed due date. Unpaid taxes then carry interest of 1.5 percent per month in counties with fewer than 3,000,000 inhabitants. In Cook County the rate is 1.5 percent per month for tax years before 2023 and 0.75 percent per month for tax year 2023 and after. Property taxes are a prior and first lien on the parcel, superior to all other liens and encumbrances, from January 1 of the levy year until the taxes are paid or the property is sold, which is what makes an Illinois certificate senior collateral.
What happens after the sale
The redemption period expires without redemption and the circuit court finds the certificate holder complied with the notice and payment requirements. The court then enters an order authorizing a judicial tax deed auction, and the property must be offered at public auction within 120 days of that order. This auction route came in with Public Act 104-0553 and applies to tax certificates issued on or after July 10, 2026, so the first judicial tax deed auctions are not expected before 2027. Certificates issued earlier still run under the older process, where the court directs the county clerk to issue the deed to the petitioner without an auction.
Leftover parcels between sales
Illinois has no statewide over-the-counter counter. Every tax lien or certificate offered at the annual sale and not sold for want of bidders is forfeited to the county as trustee for the taxing districts. The county may then sell any property it acquired, or assign any tax certificate to any party, including taxing districts, municipalities, land banks, and non-profit affordable-housing developers. Many counties run that assignment program through a delinquent tax agent, so terms, pricing, and whether private investors are served at all are county decisions rather than statutory rights. An assignee must file notice with the county clerk within 60 days setting a redemption deadline no later than 3 years from the assignment. The older route that let anyone apply to the county clerk to buy forfeited taxes no longer applies to forfeitures occurring on or after January 1, 2024.
These dates are the statewide statutory schedule. The exact auction date, registration deadline, and platform are set county by county, so confirm them on the Illinois county pages before you plan a bid. For the mechanics of the sale itself, see how to buy in Illinois.
Verified Jul 29, 2026 against Illinois statutes.
Tax Sale Atlas publishes educational information about public tax sale processes. This is not legal, financial, or investment advice. Rules, dates, and fees change; confirm with the county office before you bid.