Search and Pay LaSalle County Property Taxes

This page helps users handle Property Tax tasks in LaSalle County, Illinois, including checking tax information, paying a bill, understanding deadlines, and finding the right office for questions.

Start with the Illinois Property Tax Public Inquiry for parcel or mobile home tax information, then use the LaSalle County Treasurer payment service when you are ready to pay.

Illinois Property Tax Public Inquiry

Use the Illinois Property Tax Public Inquiry to review LaSalle County parcel or mobile home tax information online. The inquiry site requires users to accept a disclaimer before accessing records.

The LaSalle County Treasurer describes this service as a way to complete a parcel inquiry or mobile home inquiry from home. Before relying on online tax data, verify unclear or important details with county officials.

• Open the public inquiry site and read the disclaimer.
• Accept the terms to continue to the tax inquiry system.
• Use the available parcel or mobile home inquiry tools to find the record you need.
• Contact the Treasurer’s Office if the tax information is unclear or you need help with a parcel number.

Pay LaSalle County property taxes online

The LaSalle County Treasurer online payment portal lets users search for a bill by PIN, name, or address. The portal recommends leaving out punctuation when searching.

• PIN
• Name
• Address

After finding a bill, add the bill to the cart, review the selected items, then create an account or check out as a guest. An account is not required for checkout, but it can be used to view payment history or store payment methods.

• Search for the bill by PIN, name, or address.
• Select the bill or bills to pay and add them to the cart.
• Review the cart before checkout.
• Enter billing and payment information before submitting payment.

Payment options and service fees

LaSalle County property tax payments may be made by check, drop box, online payment, pay-by-phone, or through participating LaSalle County banks and financial institutions through September 9, 2026.

Convenience fees are charged by a third-party processor, not LaSalle County.

2026 due dates and late payment rules

Real estate tax due dates are July 15, 2026, and September 9, 2026. Mobile home taxes are due June 19, 2026.

No payments, including postmarked payments, are accepted after November 9, 2026.

Back taxes and tax sale questions

Prior year taxes are taxes that were not paid during the levy year and were sold at the annual tax sale. The County Clerk collects back taxes.

For back taxes, call (815) 434-8202. If the inquiry system shows that taxes were sold at tax sale, contact the County Clerk for redemption amounts.

Assessments, exemptions, and appeals

Property assessment issues are handled through the LaSalle County Assessment Office and township assessors. The LaSalle County Assessments page explains assessment notices, publications, exemptions, disaster-related reassessment, and assessment questions.

To appeal a tax bill, contact the Supervisor of Assessment office at (815) 434-8233. You may also contact your township assessor to discuss the assessment before filing a complaint.

Exemptions can reduce Equalized Assessed Value for qualifying properties. LaSalle County lists exemptions such as the General Homestead Exemption, Senior Homestead Exemption, Low-Income Senior Citizens Assessment Freeze Homestead Exemption, exemptions for persons with disabilities, veterans exemptions, returning veterans exemption, and homestead improvement exemption.

First-time exemption applications must be notarized and include a photo ID. Originals must be submitted; photocopies, faxes, and email copies are not accepted. The Senior assessment freeze PTAX-340 no longer needs to be notarized.

Property tax forms and address changes

The Treasurer’s Office provides tax and real estate forms for common property tax needs, including a tax bill address change request, FOIA information request form, mobile home affidavit, mobile home registration, bidder registration form, and taxing bodies letter of direction.

Use the LaSalle County Treasurer forms page to find available PDF forms.

LaSalle County property tax contacts

Use these contacts for payment help, assessment questions, appeals, and back taxes.

• LaSalle County Treasurer, 707 East Etna Road, Room 153, Ottawa, IL 61350
  Phone: 815-434-8219 option 4
• LaSalle County Treasurer mailing address, James L. Spelich, LaSalle County Treasurer, PO Box 1560 – 707 E. Etna Road, Ottawa, IL 61350
• LaSalle County Assessment Office, Etna Road Complex, 707 E Etna Road, Ottawa, IL 61350
  Phone: (815) 434-8233
• County Clerk back taxes
  Phone: (815) 434-8202
• Online payment help
  Phone: (877) 932-8478 or (773) 784-0709