Grundy County property tax bills for 2025 are now in the mail. The first installment is due June 26; the second is due September 4.

Residents can view their bills, assessed values, and payment options online at www.grundycountyil.gov/treasurer.

Payments can be made online, by phone (815-324-6390), by mail, at the Treasurer’s office in the Grundy County Courthouse, at the drop box outside the Sheriff’s Department, or at any of 11 participating local banks.

Participating banks: OSB Community Bank, Grundy Bank, American Commercial Bank and Trust/First National Bank, Busey Bank, Morris Building & Loan, Old National, First Federal Savings, Midland, Heartland, and Bank of Pontiac.

Credit cards and e-checks have deadlines.

Major credit cards (Visa, Mastercard, American Express, Discover) are accepted through October 31.

Electronic checks are accepted through October 15. Both carry processing fees: 2.5% for credit cards (minimum $3) and $1.50 flat for e-checks.

After October 1, only cash, cashier’s checks, credit cards, or money orders will be accepted. Personal and business checks are no longer accepted after that date.

Late payments incur a 1.5% monthly penalty, mandated by Illinois state law.