Second Installment Property Tax Bills Will Be Mailed Late

Lemont Township Assessor's Office 630-257-2522

When Cook County's second installment property tax bills are sent on time, tax bills hit mailboxes in late June and are due around August 1. This year, however, the mailing and due dates for tax bills will be delayed by at least one month, according to the Lemont Township Assessor’s Office. This means that the second installment tax bills will be due no earlier than September 1, and the due date could be later.
For decades, the county agencies involved in preparing property tax bills have been using a 1980’s-era mainframe computer system. The county has been phasing out the old mainframe for the last few years, but 2025 marks the first year in which the old system will phased out completely. This year’s tax bills will be calculated in their entirety under the new system. It appears the problems associated with the final transition to the new system are the reason for the delay in this year’s tax bills.

Release date: June 27, 2025