How do Illinois tax sales work?

Illinois holds an annual tax sale where counties auction the delinquent taxes (a tax lien) on each parcel. Bidders compete using 'penalty bidding' — bidding down a penalty rate of up to 18% per six-month period; the lowest penalty wins. The investor pays the taxes and earns the penalty when the owner redeems.

What is penalty bidding in Illinois?

Instead of a fixed interest rate, Illinois uses a penalty that accrues per redemption period (up to 18% per six months). Bidders bid the penalty down; the lowest bid (sometimes 0%) wins the lien. The penalty is the investor's return on redemption.

What is the redemption period in Illinois?

Redemption periods are generally 2 to 2.5 years (and can be extended to 3 years by the certificate holder), depending on property type. If the owner does not redeem, the holder can petition the court for a tax deed.

Where are Illinois tax sales listed?

Each county Treasurer/Collector runs the annual tax sale and publishes delinquent lists in local newspapers and online. taxsalesportal.com aggregates Illinois county tax sale listings into a single searchable database.

Illinois Tax Sales — Complete Guide for Investors

Illinois sells tax liens at an annual sale using a distinctive penalty-bidding system. Investors earn a penalty (not simple interest) when the owner redeems, and can ultimately obtain a tax deed by court petition if the property is not redeemed.

The Illinois Tax Sale Process

1. Annual Tax Sale

The county Collector offers the delinquent taxes on each parcel. Bidders bid down the penalty rate (max 18% per six months); the lowest penalty wins.

2. Certificate of Purchase

The winning bidder pays the taxes and receives a certificate of purchase, accruing the penalty per redemption period.

3. Redemption (≈2–3 Years)

The owner redeems by paying taxes plus penalty and costs. The holder may extend the redemption period (up to 3 years) before seeking a deed.

4. Tax Deed Petition

If unredeemed, the holder files a petition for a tax deed and must complete strict statutory notice ("take notice") requirements to obtain title.

Key Illinois Tax Sale Facts

Sale type	Tax lien (penalty bidding)
Max penalty	18% per 6-month period (bid down)
Auction authority	County Treasurer / Collector
Schedule	Annual
Redemption period	~2–3 years
Title	Tax deed by court petition

Due Diligence for Illinois Tax Sales

Notice compliance: The tax deed process has strict notice rules; errors can void your deed. Many investors use counsel.
Subsequent taxes: You can pay later years' taxes and add them to your certificate.
Scavenger sales: Cook County and others hold periodic "scavenger" sales for long-delinquent parcels with different rules.
Parcel research: Verify the parcel's value, condition, and any environmental issues before bidding.

This guide is informational only and not legal advice. Illinois tax sale rules vary by county — always verify details with the county Treasurer/Collector before bidding.