We Have Moved! New Location: 505 W Lynn Blvd., Sterling, IL

Assessor Office

Hours of Operation:

Monday – Friday 8:30am-3:00pm

Contact Info:

township assessor sign


  • Our Office is available for assistance with Senior Exemption and Senior Freeze forms. Your welcome to walk in or call us for an appointment.
  • Senior Exemption and Freeze forms are due July 1st. You may also submit renewals to our office.
  • Landlord Tenant Agreements are due at the county by July 1st.

Property Tax Process Overview

It is important to note that assessment of property is just the beginning of the property tax process. The Assessor’s Office has the responsibility to value property based on market value and equity. Once the Assessor’s books are closed, those values are used by taxing bodies to actually formulate your tax bill. The Assessor’s work follows the assessment process each year and concludes with the closing of the books in the fall. Once the figures are factored by the Supervisor of Assessments and finalized by the Board of Review, the various taxing bodies begin the work of levying for their budgetary needs. Each taxing body sets its levy against the total assessed valuations within its taxing district. The funds from the levy form the budget of the taxing body for the upcoming year. Taxing district lines often cross each other and overlap; your tax bill lists the taxing bodies that collectively provide services for your area of the Township. These taxing bodies include school districts, park districts, municipalities (for incorporated areas), county (for unincorporated areas), and many others. Once each taxing body determines its budget and sets its levy, they file for their tax extension with the County Clerk. The County Clerk must calculate each taxing body’s levy against its total Equalized Assessed Valuation (EAV) to derive the tax rate. The individual tax rates for each taxing body that serves your area form your overall tax rate; you can see the elements of your tax rate listed on your tax bill. Once tax rates are set, the Treasurer begins the collection process. In Whiteside County, tax bills are usually mailed in May and are paid in two installments. The first is due sometime in June; the second is due the first part of September. The above represents a brief overview of the property tax process. The Assessor’s work provides the valuation information that serves as the basis for the process, but the Assessor has no role in the setting of tax rates or the collection of tax payments.

Tax Bills & Collection

Taxes are paid in two installments in Whiteside County, with the first due sometime in June unless the date is extended because of late billing. The second installment is then due the first part of September. The Whiteside County Collector mails the tax bill to the taxpayers at least 30 days before the first installment is due. The tax bill may be paid at the Collector’s Office at the Whiteside County Courthouse in Morrison or any designated bank in Whiteside County or online (contact the Collector’s Office for this information 1-815-772-5196). It is the taxpayers’ responsibility to keep their address current with the Collector. If taxpayers do not receive a bill, they should inquire with the Collector.

Where Do My Taxes Go?

When reassessment notices are mailed in the fall we start getting calls from property owners whose first words are “My taxes are too high!” or “Why did you raise my taxes!” The Township Assessor does not raise your taxes. The job of the assessor is to come up with a fair market value of all the property in the township. From that fair market value, the assessment is computed as 33.33% of that value. All of the assessment’s are given to the supervisor of assessments in the county seat for equalization and then to the County Clerk. The County Clerk has been provided with all the levies from the taxing bodies and the tax rate is determined by dividing the total levy by the Equalized Assessed Value. Finally the tax rate is applied to each individual assessment to come up with individual tax bills.

Frequently Asked Questions

The Sterling Township Assessor Office can help with the Senior Renewal Exemption and the Senior Freeze, and these exemptions must be submitted yearly. Application forms are not necessary for the Home Improvement Exemption. All other exemptions, including the first time Senior Exemption, must be completed in Morrison at the Courthouse in the Office of Supervisor of Assessments. The Sterling Township Assessor’s office is available to assist with and notarize Senior Renewal Exemption forms and Senior Freezes Monday through Friday 8:30 a.m. – 3 p.m. and/or will get the forms to Morrison; they are due July 1. The Sterling Township Assessor’s office staff is also present on Mondays at the Senior Center in Sterling from 9 a.m. – 2 p.m. to assist with Senior Renewal Exemption forms and Senior Freezes. Homeowners can get permits from the City or County when improving or demolishing a property. A permit prompts the City or County to notify the Assessors office which initiates a field inspection to verify the details of the demolition or new construction. To qualify for the Home Improvement Exemption the property must be owned and used exclusively for a residential purpose and be your permanent full time residence. Assessed Values are modified to account for demolition and/or any new construction to your property that increases its market value. If there is new construction, the Home Improvement Exemption is then processed. Submission of forms for the Home Improvement Exemption is not necessary.

Property taxes are levied, collected, and spent locally to finance a major part of the services that units of local government provide to their residents.

Services provided by the property tax:

  • Education
  • Municipalities
  • Counties
  • Parks
  • Sanitary Districts
  • Township Governments
  • Other Special Districts
  • Local government units (e.g., municipalities, townships, counties, schools, park districts) use property tax to finance the majority of services that they provide to their citizens.
  • The largest share of local property tax (62 percent) goes to school districts for education.
  • Other public services include police and fire protection, street maintenance, and recreation.

Even in a down market, assessments can rise for the following reasons: By state law, assessments reflect the past three year’s sales and are based on a valuation day of January 1st of the current year. Therefore, they would not reflect the current market conditions. If you had a recent addition or improvement to your property, the assessment will change accordingly. On homestead property a home improvement exemption will be granted for 4 years, this reduction will be reflected on your tax bill

The first step is to determine if your assessment is out of line with the market by using an appraisal, or reviewing sales of comparable homes. Remember that these sales should have occurred within the prior three years. If your assessment reflects a value higher than the market, contact the Whiteside County Supervisor of Assessments office.

All complaints (appeals) to the Board of Review must be submitted in writing within 30 days of township publications which is typically September or October.

Typically, your assessment will not be increased simply based on a recent sale. Assessments generated for taxation purposes are to be valued using mass appraisal techniques, not on an individual property basis. This means we are required to look at trends in the market of similar homes. An individual sale may have unique influences that do not apply to other homes.

It is important that you compare assessed values instead of tax bills. 1) There are different exemptions available and they do not apply to all taxpayers. Your neighbor’s taxes may be lowered due to an exemption that you are ineligible to receive. 2) Newly constructed homes are assessed based on a completion date. If the house was completed in the middle of a calendar year, the home will be assessed on a prorated basis for that first tax billing cycle. 3) Even if you have the same model of home as someone else, the property’s value can vary due to location and amenities. Developers often make upgrades/options available to their base homes. We need to account for these differences.

Any new construction to your property that increases its market value must be reflected in your assessed value. This may include decks, patios, sun rooms, finished basements, expanding living space, etc. Our office receives copies of building permits which initiates a field inspection to verify the details of the new construction. To qualify for the Home Improvement Exemption the property must be owned and used exclusively for a residential purpose and be your permanent full time residence. The State of Illinois allows for an exemption on these improvements for a term of 4 years. The adjustment for this exemption will be applied on your tax bill. There is a $25,000 cap in assessed value (or $75,000 if full value) on the amount of value to be exempted.

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