Cook County, IL tax sales
How tax lien certificate and tax deed sales work in Cook County, seat of Chicago: sale calendar, auction platform, over-the-counter lists, and the offices that run each sale.
Verified Jul 30, 2026 against official county and state sources.
New here? Read how Illinois tax sales work, the difference between a lien and a deed, and redemption periods.
How Cook County sells delinquent taxes
Tax certificate sale (lien)
- Run by
- Cook County Treasurer's Office
- Frequency
- annual
- Typical timing
- The Treasurer's page states: "The Treasurer's Office anticipates holding the next Annual Tax Sale in December 2026." The same page adds that the sale "was originally set to be held in August 2025" and that "a new law enacted in February 2026 (Public Act 104-0460) has allowed us to delay this sale for several months." The most recent completed sale, for tax year 2022, ran December 10 through December 16, 2024, spread across five days by township volume. Cook County's annual sale schedule has slipped repeatedly, so confirm dates with the Treasurer before planning a bid.
Registration and deposit
Registration is completed online at cooktaxsale.com. The Treasurer requires bidders to review the sale rules and regulations, complete online registration, and post collateral or a bond. For the tax year 2022 sale, registration opened November 8, 2024, and both the online registration and the collateral deposit had to reach the Treasurer's Office by 5:00 p.m. Chicago time on November 27, 2024, roughly two weeks before bidding began. The full rules and regulations are posted on cooktaxsale.com when registration opens.
Cook runs a hybrid sale. Registration, collateral deposits, bid staging, and payment for certificates of purchase are all done online, but the Treasurer states that final placement of bids can only be made from computers in the Cook County Treasurer's Sale Room, Room 112 at 118 N. Clark Street (Randolph Street entrance), Chicago. Public computers are available in the Sale Room during business hours for bidders without their own machine. The list of properties eligible for sale is published in community newspapers by township ahead of the sale, and electronic delinquency lists are sold on cooktaxsale.com by ACH debit: $250 for the delinquent general real estate tax list, $250 for the delinquent special assessment list, and $100 for weekly updated lists of removals. Between sales cooktaxsale.com shows a site offline message, so the bidding site is only usable during a live sale cycle. Cook also has a separate Scavenger Sale under 35 ILCS 200/21-260 for parcels with three or more delinquent tax years, sold for cash to the highest bidder with a minimum opening bid of $250 or one half of total taxes due if that is under $500. Illinois made the Scavenger Sale optional in 2023, and the Treasurer says it now happens only at the direction of the Cook County Board. The last one completed on March 2, 2022. Redemption and certificate payouts run through the Cook County Clerk, not the Treasurer: redeemed certificates of purchase and turn in sheets go to the Clerk's Real Estate and Tax Services office at 118 N. Clark Street, Room 434, Chicago, IL 60602. As of this research the Clerk's online Delinquent Property Tax Search was temporarily unavailable during a county property tax database upgrade, though the downloadable delinquent property file was still linked from that page.
Register on RealAuctionTax deed sale
- Run by
- Sheriff or a court-appointed private selling officer, under an order of the circuit court. A county acting as trustee runs its own tax deed auctions.
- Frequency
- as ordered by the circuit court
- Typical timing
- Within 120 days after the court order authorizing the auction. Public Act 104-0553 created this route for tax certificates issued on or after July 10, 2026, so the earliest Illinois judicial tax deed auctions fall in 2027, after the 1 year short redemption track runs.
Registration and deposit
Terms of a judicial tax deed auction, including whether it runs online, in person, or both, and what deposit is required, are set in the court's order and published in the notice of tax deed auction. That notice runs once a week for 3 consecutive weeks, starting no more than 45 days and ending no less than 7 days before the auction. Read the notice for each parcel; there is no statewide platform or standing bidder registration.
Bidding opens at the tax deed judgment amount plus 0.75 percent per month since judgment, plus publication and selling officer costs. The petitioning certificate holder is entered as a credit bidder at that minimum. Surplus above the minimum goes to the county treasurer for the former owner to claim.
Over-the-counter (leftover) purchases
Certificates nobody bids on at the annual sale are forfeited to the county as trustee for the taxing districts. The county may then assign a forfeited certificate to any party or sell property it has acquired, which many counties handle through a delinquent tax agent rather than a public counter. Counties may also offer county-held certificates at a scavenger sale with a minimum bid of $250, or half the tax when total liability is under $500. Ask the county collector and the county clerk which program the county runs and who may buy.
New to this path? Read how over-the-counter certificates work.
County offices
Tax Collector (runs the certificate sale)
Notes for Cook County
- Cook County is the only Illinois county with its own statutory Scavenger Sale track (35 ILCS 200/21-260) in addition to the required Annual Tax Sale.
- The Annual Tax Sale sells the prior year's delinquent taxes as a lien, not the property. The Treasurer describes it as investors bidding on the right to pay the overdue taxes and winning a lien.
- Bidding is online through Realauction's cooktaxsale.com, but the Treasurer restricts final bid placement to computers inside its Sale Room at 118 N. Clark Street, so out of state buyers need someone physically present or must use the county's in room machines.
- Redemption periods quoted by the Treasurer for Scavenger Sale purchases are about 2.5 years for owner occupied residential property and about six months for commercial property and vacant lots, after which the buyer petitions the Circuit Court of Cook County for a deed.
- Cook's sale calendar has been repeatedly postponed by legislation, most recently by Public Act 104-0460, so treat any published date as provisional until the Treasurer posts the current year's sale page.
- All sales are final and properties are sold as is. The Treasurer disclaims accuracy of street addresses and property classifications, which are keyed only to the Property Index Number.
Illinois statewide rules
- Redemption
- Property sold at an Illinois tax sale may be redeemed at any time before the redemption period expires. Public Act 104-0553 set the standard period at 3 years from the date of sale for tax certificates issued on or after July 10, 2026. Certificates issued between January 1, 2024 and July 9, 2026 run on the earlier 2.5 year (30 month) track, and on that track the certificate holder could file a written notice with the county clerk extending redemption to a date no later than 3 years from the sale. A short 1 year period applies when the parcel was, on the date of sale, vacant non-farm property, commercial or industrial property, or improved with a structure holding 7 or more residential units. Certificates the county holds or assigns as trustee run on their own schedule under Section 21-385, and an assignee must file notice within 60 days of assignment setting a redemption deadline no later than 3 years from the assignment.
- Deed deposit
- Illinois does not fix a statutory deposit percentage. Deposit and payment terms are set in the court's order authorizing the auction and by the selling officer, so read the notice of tax deed auction for each sale. A purchaser who fails to complete the sale forfeits any deposit already made to the county surplus equity fund, and the court orders a new auction of the property.
- Surplus proceeds
- Any amount by which the winning bid exceeds the minimum bid is surplus. Within 30 days after the court confirms the sale the selling officer deposits the surplus with the county treasurer, who notifies everyone who received the Section 22-10 take notice that the owner at the time of the sale may file a claim for it. A county running its own tax deed auction deposits surplus with the treasurer within 30 days of the sale and notifies interested parties within 60 days. Separately, a previous owner who lost equity through a tax deed can claim an award from the county surplus equity fund, capped at the value of the property when the deed issued less mortgages, liens, and the taxes the purchaser paid.
A tax deed does not convey marketable title. Most buyers file a quiet title action before they can resell or insure the property. See the due diligence guide.
Frequently asked questions
Does Cook County, Illinois sell tax liens or tax deeds?
- Cook County follows Illinois's tax lien state system.
When is the Cook County tax certificate sale?
- The Treasurer's page states: "The Treasurer's Office anticipates holding the next Annual Tax Sale in December 2026." The same page adds that the sale "was originally set to be held in August 2025" and that "a new law enacted in February 2026 (Public Act 104-0460) has allowed us to delay this sale for several months." The most recent completed sale, for tax year 2022, ran December 10 through December 16, 2024, spread across five days by township volume. Cook County's annual sale schedule has slipped repeatedly, so confirm dates with the Treasurer before planning a bid.. Registration and bidding happen on the county's online platform. Always confirm the exact date with the Tax Collector before the sale.
How often does Cook County hold tax deed sales?
- as ordered by the circuit court. Each sale is scheduled and advertised in advance, so check the county's tax deed calendar for the next posted date.
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.
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