The Cook County Treasurer will soon release 1st installment 2010 property tax bills with an extended due date of April 1, 2011.
The extended due date is a one time change due to recent legislation passed by the Illinois Legislature and by law will revert back to the March 1 due date for subsequent years.
The 1st installment tax bill is an estimated tax bill. The amount due will be 55% of the prior year's total tax. Any change in the 2010 tax bill (due to changes in exemptions, assessment value, tax rate or equalization factor) will be reflected on the 2nd installment bill issued in the fall.