Does your Naperville property tax assessment look too high this year? You are not alone, and you have options. With a clear plan and the right evidence, you can challenge your assessed value and potentially lower your future tax burden. This guide walks you through the Naperville process in both DuPage and Will counties, including deadlines, steps, evidence, and official links. Let’s dive in.
Know your county and township
Naperville spans two counties. Parcels north and west of town are generally in DuPage County, while many south and southeast areas fall in Will County. Your exact appeal path depends on your parcel’s county and township.
- DuPage County parcels: Start with your township assessor, then file with the DuPage County Board of Review if needed. Naperville Township’s page explains how to review your Property Record Card and submit an appeal inquiry. See the local guidance on the Naperville Township Assessor appeal page.
- Will County parcels: Follow instructions from the Will County Supervisor of Assessments and Board of Review. Forms and filing details are posted each year on the Will County BOR portal downloads page.
Tip: Find your Parcel ID on your tax bill, then confirm which county and township cover your property before you begin.
Mark your deadlines
Illinois law sets a strict 30-day deadline to file with the County Board of Review after your township’s assessment list is published. Missing it usually means you cannot appeal that year’s assessed value. You can review the statutory rule in 35 ILCS 200/16-55.
- Publication dates vary by township and year. In our area, many notices run in late summer to early fall. The filing window then stays open for about 30 days. Will County publishes the annual window and forms on the official BOR portal.
- Many township assessor offices also offer an earlier, informal review period. Some list July submission targets for assessment review inquiries. Check local instructions on the DuPage Township Assessor assessment review page.
Follow this step-by-step process
- Confirm your county and township
- Verify your parcel’s county and township using your tax bill or local property search. Naperville parcels can be in DuPage or Will, which determines where you file.
- Review your Property Record Card and find comparables
- Look for factual errors, like square footage, bedroom and bathroom counts, or finished basement status. Pull recent, arm’s-length sales that match your home’s style, size, and amenities.
- Try the township’s informal review first
- Many issues are resolved by the assessor before the Board of Review window opens. Follow the submission instructions for an assessment review inquiry. Local guidance and evidence expectations are outlined on the DuPage Township Assessor page.
- File a formal Board of Review complaint if needed
- If informal review does not resolve your concerns, submit a formal complaint within the 30-day window. Will County provides fillable forms and upload instructions on the BOR portal downloads page. DuPage parcels file with the DuPage County Board of Review using county-provided forms.
- Prepare for a hearing or a review on the record
- The Board of Review may hold a brief hearing or decide based on your written evidence if you waive appearance. The Board can lower, raise, or leave your assessment unchanged, as permitted by state statute.
- Consider next steps after the BOR decision
- If you disagree with the Board of Review outcome, you can appeal to the Illinois Property Tax Appeal Board. Petitions are generally due within 30 days of the BOR’s written decision, per Illinois rules discussed on Justia and the PTAB overview.
What evidence works in Naperville
Winning appeals focus on value and uniformity, not the tax bill amount. Build a clear, concise packet.
- Correct the facts: PRC errors on living area, condition, beds and baths, or basement finish are strong grounds for adjustment. Local assessor pages explain how to submit supporting details.
- Overvaluation: Use recent, truly comparable sales near the valuation date. Many assessors rely on a three-year sales window, with values as of January 1 of the assessment year. The DuPage Township Assessor explains typical sales windows and evidence standards.
- Lack of uniformity: Show that similar properties are assessed at a lower level relative to market value using assessment comparables.
Evidence checklist you can use:
- Completed county Board of Review complaint form.
- Photos showing exterior condition and any notable interior issues.
- Recent comparable sales with closing date, price, and addresses.
- Closing Disclosure if you purchased recently and your argument is based on that sale.
- Full appraisal, if available, with a valuation date tied to January 1 of the assessment year.
- A copy of your Property Record Card with any corrections highlighted.
Avoid common mistakes
- Appealing the tax bill instead of the assessed value. Tax rates are set by taxing districts. Focus on market value or uniformity evidence.
- Missing the 30-day Board of Review deadline. This usually ends your chance to contest the current year’s valuation.
- Using weak comparables. Choose properties that match your home’s size, style, age, and features and fall within the assessor’s sales window.
- Skipping instructions for hearings or waivers. Follow the county’s rules for appearance, written submissions, and deadlines.
Where to find forms and portals
- DuPage portion of Naperville: Review the Naperville Township Assessor appeal guidance to check your PRC, evidence expectations, and how to contact the office. DuPage parcels ultimately file with the county Board of Review.
- Will County parcels: Download residential appeal packets and check filing windows on the Will County BOR portal.
- Township informal review: Many townships outline assessment review steps, evidence, and typical timelines on the DuPage Township Assessor page.
When to take it further
If your Board of Review decision still feels off, the next administrative step is the Illinois Property Tax Appeal Board. Learn what PTAB does in this overview and note that petitions are generally due within 30 days after the BOR decision, as discussed on Justia. Complex matters can benefit from professional guidance, but many homeowners manage the process themselves with solid evidence and timely filing.
Ready to talk strategy or sanity-check your comparables? Reach out to Vikes RE for a straightforward conversation about your property goals and next steps.
FAQs
What is the deadline to appeal a Naperville assessment?
- Illinois law generally requires you to file with the County Board of Review within 30 days of your township’s assessment publication date for that tax year.
How do I know if my Naperville home is in DuPage or Will County?
- Check your tax bill for your Parcel ID and county, or use your township’s property search; Naperville spans both DuPage and Will counties, and your appeal path depends on where your parcel sits.
Can my assessment go up if I appeal in Naperville?
- Yes, the Board of Review can lower, raise, or leave your assessment unchanged, so present accurate comparables and correct any factual errors.
What evidence helps most in a Naperville appeal?
- Strong comparables, a recent arms-length purchase with a Closing Disclosure, a credible appraisal with the correct as-of date, clear photos, and corrections to your Property Record Card.
What happens if I miss the 30-day Board of Review deadline?
- You generally lose the chance to challenge that assessment year’s value at the BOR or PTAB, so mark your calendar and file on time.