Some taxpayers choose to prepay the First Installment tax for reasons such as winter travel or to increase their tax write-offs for the current year. Cook County taxpayers may choose to participate in the optional program of prepaying their First Installment taxes during December.

How is the First Installment Calculated?

The First Installment is an estimated bill equal to 55% of the prior year's total tax. A law passed by the Illinois Legislature in 2009 raises the First Installment tax from 50% to 55% of the prior year's total tax (or 55% of the adjusted tax if an assessment certificate of error is certified by the previous Nov. 30).  Second Installment tax amount vary.  For this reason, you cannot prepay the Second Installment, and you should never double the First Installment amount and expect it to be credited to the Second Installment.

If You Wish to Participate in the Prepayment Program

To request a prepayment bill, send a note (or email) separate from any tax payment by early December that includes your mailing address and Property Index Number (PIN) to:

Cook County Treasurer
Attn: Prepayments
118 North Clark Street, Suite 112
Chicago, IL 60602

If your prepayment is received by December 31st, the First Installment tax bill which will be mailed in late January will reflect the prepayment. If the prepayment is received after December 31st,  the regularly mailed bill in January may not reflect the prepayment.

1. Make checks payable to the Cook County Treasurer.
2. Make sure your name, address, PIN, phone number, the word "Prepayment" in the memo line, and, if available, your email address, are all on the face of the check(s).
3. Submit only one check per original payment coupon for the exact amount. Overpayments will be returned, as will any individual check submitted for multiple PINs.
4. Your canceled check(s) will serve as your receipt(s).
5. Prepayments for the upcoming First Installment taxes can be accepted only if the the prior year's taxes have been paid in full. You may verify your payment status by selecting Payment Status.

Sample Check:

Prepaying by Mail

Your payment must be postmarked by December 31st, to be reflected in the regular bills that will be mailed in January. Send the payment with the original tax bill payment coupon to:

Cook County Treasurer
P.O. Box 4468
Carol Stream, IL 60197-4468

Prepaying in Person

You may submit your original payment coupon and payment at any of more than 390 Chase Bank locations throughout Chicagoland.