Delinquent Property Taxes in Illinois: The County Auctions Your Tax Bill, and the Penalty Doubles Every Six Months
Reviewed by DocDraft Legal Team · Illinois · Last updated October 21, 2026
What Illinois sells when property taxes go unpaid is the tax bill, bought at a reverse auction where investors compete by bidding the penalty down from a 9 percent ceiling. Delinquent property taxes are taxes a homeowner failed to pay by the date the state set, after which the county adds interest and can eventually force a sale to collect them. The county collector holds that annual tax sale under a circuit court judgment and order of sale, the bidder offering to pay the amount due for the least penalty percentage wins, and no bid above 9 percent of the tax may be accepted (35 ILCS 200/21-215). The county clerk hands that bidder a tax certificate (35 ILCS 200/21-250). You keep title. Before the sale, interest runs at 1 1/2 percent per month, or portion of a month, in a county with fewer than 3,000,000 inhabitants, and at 0.75 percent a month in a county with 3,000,000 or more for tax year 2023 onward (35 ILCS 200/21-15). Buying the taxes back is not an interest calculation. You owe the certificate amount plus the winning penalty bid, multiplied once for every six month penalty period that has run since the sale, up to six times at 36 months (35 ILCS 200/21-355). All redemption periods shall begin on the date of the tax sale (35 ILCS 200/22-5). For a certificate issued on or after July 10, 2026 that gives you 3 years, or 1 year on vacant, commercial, industrial or larger multi-unit property (35 ILCS 200/21-350). Attorney review is available through DocDraft.
Find out where you stand in Illinois
Where are you with the unpaid property taxes?
DocDraft provides document preparation, not legal advice.
How long do I have to redeem sold taxes in Illinois?
Property sold at a tax sale may be redeemed at any time before the expiration of 3 years from the date of sale, except 1 year where the parcel was vacant non-farm, commercial, industrial, or held a structure with 7 or more residential units on the sale date (35 ILCS 200/21-350).
What is the penalty to redeem delinquent property taxes in Illinois?
Not a rate, a multiplier. You owe the certificate amount times the penalty bid at sale if you redeem within 6 months, twice that bid between 6 and 12 months, and so on by six month steps to six times the bid between 30 and 36 months (35 ILCS 200/21-355).
Where do I pay to redeem delinquent property taxes in Illinois?
The county clerk of the county where the property sits, not the treasurer and not the investor. The deposit must be legal money, a cashier's check, a certified check, or a post office or bank money order, payable to the county clerk (35 ILCS 200/21-355).
When do Illinois property taxes become delinquent each year?
On the later of the statutory date or the date on your bill. The first installment is delinquent on the later of June 1 or the day after the bill's first due date, the second on the later of September 1 or the day after the bill's second due date (35 ILCS 200/21-15).
Illinois delinquent property tax rules at a glance
In Illinois an unpaid property tax bill becomes a debt the county can sell to a stranger, who then holds a lien on your home while the charge to clear it grows in steps. That is what delinquent property taxes mean here: taxes missed past the statutory date, after which the county adds interest and can force a sale to collect. Three features set Illinois apart. The charge is a penalty percentage won by reverse auction, capped at 9 percent of the tax, that multiplies by six month period rather than accruing by the day (35 ILCS 200/21-215, 21-355). The redemption clock runs from the sale date, not from the delinquency (35 ILCS 200/22-5). And since July 10, 2026 the certificate holder cannot simply take your deed: the circuit court orders a public auction and surplus above the judgment amount comes back to you (35 ILCS 200/22-40, 22-42).
A Winnebago County two flat that crosses the twelve month line two days late
Start with a Winnebago County two flat whose owner skipped the second installment, so interest ran at 1 1/2 percent a month under 35 ILCS 200/21-15 and the collector applied for judgment within 90 days after the second installment due date (35 ILCS 200/21-150). At the annual sale a bidder takes the parcel at a 4 percent penalty bid, well under the 9 percent ceiling in 35 ILCS 200/21-215, on a certificate amount near 5,200 dollars. Redeem in month 11 and the penalty line is twice that bid, 8 percent, about 416 dollars. Cross the 12 month mark and it becomes three times the bid, 12 percent, about 624 dollars (35 ILCS 200/21-355). Illustration only. The figure that binds is the county clerk's estimate.
Relevant Laws
35 ILCS 200/21-15 (when taxes go delinquent and the monthly interest rate)
Provides that property on which the first installment remains unpaid on the later of June 1 or the day after the first installment due date on the bill is deemed delinquent and bears interest from that date, with the same rule and a September 1 date for the second installment. Sets the interest at 1 1/2 percent per month or portion thereof in a county with fewer than 3,000,000 inhabitants, and in a county with 3,000,000 or more at 1.5 percent a month for tax years before 2023 and 0.75 percent a month for tax year 2023 and thereafter. Payment received by mail and postmarked on or before the due date is not delinquent.
35 ILCS 200/21-25 (accelerated billing due dates in a county of 3,000,000 or more)
Provides that in a county with 3,000,000 or more inhabitants using the accelerated billing method, the estimated first installment is deemed delinquent and bears interest after March 1, and for all tax years the second installment is deemed delinquent and bears interest after August 1 annually, at 1 1/2 percent a month for tax years before 2023 and 0.75 percent a month for tax year 2023 and after. Sets a 0.75 percent rate after April 1, 2026 for the tax year 2025 first installment.
35 ILCS 200/21-27 (waiver of the delinquency interest penalty)
Lets a county board, on the county treasurer's recommendation, adopt a resolution waiving the interest penalty otherwise imposed under Sections 21-15, 21-20 or 21-25 for a person determined eligible for a grant under the Senior Citizens and Persons with Disabilities Property Tax Relief Act, who requests the waiver in writing on a form approved by the treasurer on or before the first day of the month the installment is due and pays that installment in full on or before the third day of the month. Also provides a brownfield site waiver.
35 ILCS 200/21-110 and 21-115 (published notice of the application for judgment and sale)
Section 21-110 requires the collector, after all taxes have become delinquent, to publish an advertisement giving notice of the intended application for judgment and tax sale, including the PIN of each delinquent property. Section 21-115 requires that advertisement to be published once at least 10 days before judgment is applied for, with the list of delinquent properties, owners' names, total amount due and years due, and requires notice of a date within the next 5 business days on which the properties will be sold to the county or exposed to public tax sale.
35 ILCS 200/21-135 (mailed notice before the application for judgment and sale)
Requires the county collector, not less than 15 days before the date of application for judgment and sale, to mail by registered or certified mail a notice of the forthcoming application to the party in whose name the taxes were last assessed or to the current owner of record, stating the intended dates of application and commencement of the sale and describing the properties, and requires the collector to present proof of mailing to the court with the application. The collector collects 10 dollars from the proceeds of each sale for those costs.
35 ILCS 200/21-150 (when the collector must apply for judgment and order of sale)
Requires that in a county with fewer than 3,000,000 inhabitants all applications for judgment and order of sale be made within 90 days after the second installment due date, and in Cook County within 365 days of the second installment due date. Sets Cook County carve-outs: the 2023 annual tax sale application on or before December 1, 2026 and the 2024 annual tax sale application on or before April 1, 2027, and provides that in Cook County interest shall not accrue between September 2, 2025 and January 1, 2027 on delinquent warrant year 2023 tax balances. The court hears the matter within 30 days and the sale begins within 5 business days.
35 ILCS 200/21-190 (entry of judgment for tax sale and county purchase)
Provides that if judgment is rendered the county collector shall, after publishing notice, proceed to conduct a tax sale pursuant to the judgment. Lets a county board in a county with fewer than 3,000,000 inhabitants submit a list of properties it offers to purchase at the sale. Requires that in a county with 3,000,000 or more inhabitants, for the seventh tax sale conducted after July 10, 2026 and all later ones, the county offer to purchase all properties offered for the total tax amount due, and prohibits it from doing so at the first 6 such sales except under the Section 21-191 pilot.
35 ILCS 200/21-205 (how the annual tax sale is conducted)
Requires the collector to attend on the day and place in the notice and offer for sale, separately and in consecutive order, all property on the list whose taxes, special assessments, interest or costs are unpaid, between 9 a.m. and 4 p.m., or 8 a.m. to 8 p.m. in a county with 3,000,000 or more inhabitants, continuing day to day until all property has been offered. Requires an automated bidding system programmed to accept the lowest redemption price bid, or digital recording of the sale, and a single bidder rule in counties of 275,000 or more inhabitants.
35 ILCS 200/21-215 (penalty bids and the 9 percent ceiling)
Provides that the person at the sale offering to pay the amount due on each property for the least penalty percentage shall be the purchaser of that property, and that no bid shall be accepted for a penalty exceeding 9 percent of the amount of the tax or special assessment on property. Provides that where the county offers to purchase under Section 21-190(b) or (c) the county shall be the purchaser notwithstanding any other offer, and that the penalty bid on such a county purchase shall be 0.75 percent per month, subject to a county clerk payment plan under Section 21-385(d).
35 ILCS 200/21-250 (the tax certificate the winning bidder receives)
Requires the county clerk to make out and deliver to the purchaser of any property sold under Section 21-205 a tax certificate countersigned by the collector, describing the property sold, the date of sale, and the amount of taxes, special assessments, interest and cost for which they were sold, and confirming that the sale price has been paid. Provides that a tax certificate is assignable by endorsement and that an assignment vests in the assignee all the right and title of the original purchaser.
35 ILCS 200/21-260 (the collector's scavenger sale and its separate interest ladder)
Orders long-delinquent properties sold at public sale or electronic automated sale to the highest bidder for cash, even where the bid is less than the full amount of taxes, penalties and costs, with a minimum bid of 250 dollars or one half of the tax where the total liability is under 500 dollars. Subsection (f) provides that in lieu of penalty the person redeeming pays interest on a fixed ladder, for sales on or after September 9, 1993 at 3 percent a month for each of the first 2 months, 12 percent at 2 to 6 months, 24 percent at 6 to 12, 36 percent at 12 to 18, 48 percent at 18 to 24, and after 24 months the 48 percent plus 6 percent per annum.
35 ILCS 200/21-296 (the surplus equity fund and the fee that builds it)
Creates a county surplus equity fund. In counties of less than 3,000,000 inhabitants a purchaser pays the county collector a nonrefundable surplus equity fee set by the collector of not more than 20 dollars for each item purchased, with a like sum for each year subsequent taxes are paid and posted. In counties of 3,000,000 or more the fee is 5 percent of the total taxes, interest and penalties for each certificate, capped at 1,000 dollars, plus 80 dollars for each year subsequent taxes are posted. Amounts paid are included in the amount required to redeem under Section 21-355, except the nonrefundable per-item fee.
35 ILCS 200/21-302 (claiming surplus equity after a tax deed already issued)
Gives a previous owner who sustains loss or damage by reason of the issuance of a tax deed the right to recover surplus equity lost in the property through an award from a county surplus equity fund. For tax deeds recorded in the 2 years before July 10, 2026 the claim must be filed not later than 2 years after that date. For outstanding certificates issued before that date that result in deeds recorded after it, the claim must be filed not later than 2 years from the date of deed recording. The award is limited to the property's value when the deed issued, less mortgages, liens and the amounts the section lists.
35 ILCS 200/21-350 (the period of redemption, 3 years or 1 year)
Provides that property sold at a tax sale may be redeemed at any time before the expiration of 3 years from the date of sale, except that where on the date of sale the property was vacant non-farm property, carried a structure or structures with 7 or more residential units, or was commercial or industrial property, it may be redeemed at any time before the expiration of 1 year from the date of the tax sale. Its applicability clause ties the Public Act 103-555 changes to tax certificates issued on or after January 1, 2024 and the Public Act 104-553 changes to certificates issued on or after July 10, 2026, so the governing period depends on when the certificate issued.
35 ILCS 200/21-355 (what the redemption deposit must cover, and the penalty periods)
Requires the person redeeming to deposit the amount specified with the county clerk of the county where the property sits, in legal money, cashier's check, certified check, post office money order or a money order from a federally insured institution, timely only if received in person before the close of business on or before expiration of the redemption period or mailed with a cancellation mark dated at least one day earlier. The deposit covers the certificate amount, the accrued penalty computed as the certificate amount times the penalty bid once for each six month period to six times between 30 and 36 months, every subsequent year of taxes the holder paid plus 12 percent on each for each year or portion, the county clerk's Section 22-5 fees, circuit clerk and sheriff fees, 35 dollars once a petition is filed, 4 dollars for the Section 22-5 notice, up to 150 dollars for a title search, publication costs, municipal advancements and receivership costs.
35 ILCS 200/21-385 (extending the redemption period, and the county payment plan)
Lets a purchaser or assignee, other than a county as trustee, extend the period of redemption by filing with the county clerk a written notice describing the property, stating the date of sale and specifying the extended period, but only for a period expiring not later than 3 years from the date of sale, and requires the clerk to stamp the date of receipt. Extends county-held certificate redemption by operation of law to the deadline the county sets in its petition for tax deed. Subsection (d) lets a county clerk create and administer a payment plan during the redemption period for county-held certificates and waive interest penalties under it.
35 ILCS 200/22-5 (the take notice, and when the redemption clock starts)
Requires the purchaser or assignee, within 4 months and 15 days after any tax sale, to deliver to the county clerk a take notice in at least 10 point type in the statutory form, which must state the date the right to redeem expires and direct the owner to contact the county clerk for the amount owed, and requires the clerk to mail copies by registered or certified mail within 10 days. States that all redemption periods shall begin on the date of the tax sale. In counties of 3,000,000 or more the notice must carry a provision in Spanish, Polish and Mandarin Chinese.
35 ILCS 200/22-10 (notice of expiration of the period of redemption)
Bars a purchaser or assignee from requesting an order for a judicial tax deed auction and a tax deed unless, not less than 3 months nor more than 6 months before the period of redemption expires, it gives notice of the sale and of the expiration date to owners, occupants, the municipality or county, and interested parties including any mortgagee of record. Prescribes the notice form, which tells the owner redemption can be made by applying to the county clerk and that if there is extra money after taxes and fees the owner may get it.
35 ILCS 200/22-40 (order authorising a judicial tax deed auction, and the judgment amount)
Requires the petitioner to prove the redemption period expired without redemption, that later taxes and sales are paid or redeemed, that the notices required by law were given and municipal advancements paid. On sufficient evidence the court enters an order authorising a judicial tax deed auction, insisting on strict compliance with Sections 22-10 through 22-25. Defines the tax deed judgment amount, including a fee not exceeding 50 percent of the then-allowable Illinois foreclosure attorney fees published by Fannie Mae, accruing interest at 0.75 percent a month. Requires the property to be offered at public auction within 120 days after the order and sold to the highest bidder.
35 ILCS 200/22-42 (the judicial tax deed auction and the owner's surplus claim)
Governs the auction: notice content, mailing to interested parties and to the owner, minimum bid, adjournment, and distribution. Subsection (h) requires the county treasurer, within 60 days following deposit of surplus funds, to notify all parties who received the Section 22-10 take notice that the owner at the time of sale may submit a claim for the surplus to the county treasurer or the circuit court within 3 years of the date on the notice. Subsection (k) sends surplus unclaimed after 3 years to the Revised Uniform Unclaimed Property Act, and subsection (l) gives the claimant the interest earned while the treasurer held it.
35 ILCS 200/22-85 (the holder's own deadline, and when the certificate goes void)
Provides that unless the holder of the certificate purchased at any tax sale takes out the deed in the time provided by law and records it within one year from and after the time for redemption expires, the certificate or deed and the sale on which it is based shall, after that one year period, be absolutely void with no right to reimbursement. Time the holder is prevented from obtaining a deed by a court injunction or order, by a court's refusal or inability to act on the application, or by the clerk's refusal to execute the deed is excluded from the one year.
Illinois Public Act 104-0553, effective July 10, 2026
The Illinois General Assembly's public act page for the enactment that rewrote this chapter, displaying Public Act 104-0553 with Effective Date 7/10/2026. It amended Sections 21-110, 21-115, 21-150, 21-190, 21-205, 21-215, 21-296, 21-302, 21-350, 22-5, 22-10, 22-40 and 22-42 of the Property Tax Code, among others, lengthening the general redemption period in Section 21-350 to 3 years from the date of sale and replacing the direct issuance of a tax deed with a court-ordered judicial tax deed auction that returns surplus proceeds to the former owner.
Cook County Clerk: tax redemption and the estimate of the cost of redemption
The county clerk page for the office that actually takes a redemption payment in Illinois' largest county, confirming that the clerk's office can provide you with an Estimate of the Cost of Redemption. It is cited here for that procedural fact only. Note that the page's description of the residential redemption window reflects the law before Public Act 104-0553, so the statutory period in 35 ILCS 200/21-350 and the expiration date the clerk states for your own certificate control.
Regional Variances
Illinois delinquent property tax rules at a glance
Sale mechanism
Lien first, then a court-ordered deed auction. The county collector sells the delinquent taxes at an annual tax sale under a circuit court judgment and order of sale, and the county clerk issues the winning bidder a tax certificate (35 ILCS 200/21-205, 21-250). Bidding is a reverse auction on the penalty percentage (35 ILCS 200/21-215). Separate routes exist for the collector's scavenger sale (35 ILCS 200/21-260) and for the county taking the certificate as trustee for the taxing districts (35 ILCS 200/21-90).
Delinquency dates
Two installments, and the later of two dates controls. Ordinarily the first installment is delinquent on the later of June 1 or the day after the first due date printed on the bill, the second on the later of September 1 or the day after the second due date (35 ILCS 200/21-15). Under accelerated billing in a county of 3,000,000 or more inhabitants, the estimated first installment is delinquent after March 1 and the second after August 1 (35 ILCS 200/21-25).
Interest before the sale
The delinquency charge is interest, and its rate splits by county size. 1 1/2 percent per month or portion of a month in a county with fewer than 3,000,000 inhabitants; in a county with 3,000,000 or more, 1.5 percent a month for tax years before 2023 and 0.75 percent a month for tax year 2023 and after (35 ILCS 200/21-15). A portion of a month counts as a month, so the charge steps rather than accruing daily. A 10 dollar cost is also collected from a taxpayer who pays after the application notice is mailed (35 ILCS 200/21-135).
Time before the sale
Months, driven by the collector's annual application rather than a fixed wait. In a county with fewer than 3,000,000 inhabitants the application for judgment and order of sale is due within 90 days after the second installment due date; in Cook County within 365 days of it, with the 2023 sale application due by December 1, 2026 and the 2024 sale application by April 1, 2027 (35 ILCS 200/21-150). The sale begins within 5 business days of the application.
Redemption period and clock
The clock starts at the sale. All redemption periods shall begin on the date of the tax sale (35 ILCS 200/22-5). For a certificate issued on or after July 10, 2026 the period is 3 years from the date of sale, except 1 year where the parcel was vacant non-farm, commercial or industrial, or carried a structure with 7 or more residential units on the sale date (35 ILCS 200/21-350). That section's applicability clause ties the length to the certificate's issue date, so ask the county clerk for the expiration date on yours.
Redeemer's charge
A flat penalty percentage that multiplies by six month period, not an annual rate and not a daily accrual. The percentage is bid down at the sale, where the bidder taking the least penalty percentage wins and no bid above 9 percent of the tax may be accepted (35 ILCS 200/21-215). That bid is then multiplied once inside 6 months of the sale, twice to 12 months, three times to 18, four times to 24, five times to 30, and six times to 36 (35 ILCS 200/21-355).
Other redemption costs
The certificate amount, every later year of taxes the holder paid plus 12 percent on each for each year or portion, county clerk fees under Section 22-5, circuit clerk and sheriff fees, 35 dollars once a petition for tax deed is filed, 4 dollars for the take notice, up to 150 dollars per redemption for a title search, publication costs, municipal advancements and receivership costs (35 ILCS 200/21-355). The surplus equity fee paid at purchase is also included (35 ILCS 200/21-296).
Notice to the owner
Four notices in sequence. Published advertisement of the intended application for judgment at least 10 days beforehand (35 ILCS 200/21-110, 21-115); registered or certified mail not less than 15 days before the application, with proof of mailing filed in court (35 ILCS 200/21-135); a take notice delivered to the county clerk within 4 months and 15 days of the sale (35 ILCS 200/22-5); and notice of the expiration of redemption not less than 3 nor more than 6 months before it expires (35 ILCS 200/22-10).
Where to redeem
The county clerk of the county where the property sits, not the county treasurer, not the collector and not the certificate holder. The deposit must be legal money, a cashier's check, a certified check, a post office money order or a money order from a federally insured institution, payable to the county clerk, and received in person before the close of business on or before expiration, or mailed with a cancellation mark dated at least one day earlier (35 ILCS 200/21-355).
Surplus proceeds
Claimable, and this is the newest piece of Illinois law. The circuit court orders a judicial tax deed auction within 120 days of its order (35 ILCS 200/22-40), and within 60 days of the surplus being deposited the county treasurer must notify the take notice recipients that the owner at the time of sale may claim it within 3 years of the date on that notice (35 ILCS 200/22-42). A previous owner whose deed was recorded in the 2 years before July 10, 2026 has a separate surplus equity claim due within 2 years after that date (35 ILCS 200/21-302).
Payment plan
Only where the county holds the certificate. A county clerk may create and administer a payment plan during the redemption period for county-held certificates and may waive interest penalties when payments are made within its parameters (35 ILCS 200/21-385). For a privately held certificate, Section 21-355 requires a single deposit of the full amount. A county board may also waive delinquency interest for a person eligible under the Senior Citizens and Persons with Disabilities Property Tax Relief Act (35 ILCS 200/21-27).
Frequently Asked Questions
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