Are you trying to make sense of your Naperville property tax bill or what happens to taxes when you buy or sell? You are not alone. Property taxes touch your monthly payment, your closing costs, and your annual budget. In this guide, you will learn how taxes are assessed and billed, how escrow works with your lender, what changes when a home is in DuPage versus Will County, and how tax prorations show up on your closing statement. Let’s dive in.
Property tax basics
Property taxes fund local services that benefit your neighborhood. Your bill combines the levies from several taxing bodies, which often include your school district, the City of Naperville, the county, the library, the fire district, and the Naperville Park District. Each body sets a budget, and the county converts those budgets into a combined tax rate for your property.
Who does what
- Assessor or Supervisor of Assessments: Estimates your home’s assessed value based on its market value as of January 1 for the assessment year.
- County board, clerk, and taxing districts: Approve budgets and levies that drive the tax rate.
- County treasurer: Calculates, mails, and collects tax bills.
- State: Provides statutes and equalization guidance.
- Lender or servicer: Manages your escrow account if your mortgage requires one.
- Title company or closing agent: Prorates taxes at closing based on local custom and your contract.
How your bill is calculated
Your total tax bill is the result of a few steps working together:
- Market value estimate
- The assessor uses a valuation date of January 1 for the assessment year.
- Assessment level
- Residential assessments are calculated as a percentage of market value. The result is the assessed value.
- Exemptions applied
- Common exemptions can reduce your taxable value, such as the General Homestead, senior exemptions, and exemptions for qualifying disabled persons or veterans. Check your county assessor to review programs, eligibility, and deadlines.
- Equalization factor
- A county or state equalization multiplier may be applied to create the Equalized Assessed Value, or EAV.
- Combined tax rate
- The levies of all taxing districts serving your property are converted into a single rate.
- Final bill
- Bill amount is typically EAV multiplied by the combined rate. Some bills show dollars per $100 of EAV for clarity.
Practical tip: The Naperville Park District is one of the taxing bodies that contributes to your combined rate. It is not the only line on your bill, but it is part of the total.
DuPage vs. Will: what changes
Naperville spans two counties. Your property is either in DuPage County or Will County, and that matters because each county runs its own billing timeline and installment structure.
- Mailing dates differ. One county may mail earlier than the other in a given year.
- Installment schedules differ. Due dates, grace periods, and penalties can vary by county and by year.
- Closing impacts differ. Whether a bill has been mailed or paid before your closing affects how taxes get prorated between buyer and seller.
Always confirm the county for your property and check the county treasurer and assessor sites for the current year’s mailing and due date schedules. Do not rely on last year’s dates.
Annual timeline overview
While exact dates change by county and year, the general flow looks like this:
- January 1: Assessment date for the year’s valuation.
- Late winter to spring: Assessment notices go out and appeal windows open.
- Late fall: Taxing bodies adopt budgets and levies for the upcoming bill.
- Winter to spring: Counties prepare and mail tax bills.
- Installments due: Counties set one or more due dates for the bill. Check your county treasurer for the current schedule.
Escrow accounts explained
If you have a mortgage with an escrow requirement, your lender collects money each month to pay taxes and insurance on your behalf.
- Monthly collection: The lender estimates 12 months of taxes, divides by 12, and adds that amount to your payment.
- Initial deposit at closing: Most lenders collect a few months of taxes to start your escrow with a cushion.
- Annual escrow analysis: Each year, the lender compares what was collected to what was paid. If taxes rise, your monthly escrow usually increases. If there is a surplus, you may receive a refund or a lower monthly escrow.
If you buy with cash or have an escrow waiver, you are responsible for paying the county directly by the due dates.
Tax prorations at closing
At closing, taxes are typically split so each party pays for the time they owned the home. The closing agent follows the contract and local custom to calculate credits or debits.
Common methods:
- Bill-based proration: Uses the most recent actual bill, often last year’s, for a simple calculation.
- Accrual or estimated proration: Adjusts last year’s bill to estimate the current year based on known changes, like exemptions or assessment updates.
Typical scenarios:
Scenario A: Bill issued and paid before closing
- You, as the buyer, usually credit the seller for the portion of the year you will own the home after closing. Your lender then sets your escrow based on the latest bill and payment history.
Scenario B: Bill not issued by closing
- The title company often uses last year’s bill or an estimate to prorate. Later, when the bill arrives, your lender pays it from your escrow. The credits you received at closing cover the seller’s share.
Scenario C: Bill issued but unpaid at closing
- Taxes are prorated, and the seller’s share is collected or held back so the bill can be paid promptly. The closing agent will coordinate that process.
Two key reminders:
- Verify county of record. DuPage and Will often mail at different times, which affects whether you see Scenario A, B, or C.
- Confirm the proration method. Ask the title company which method they use and make sure it is noted on your closing statement.
Naperville Park District’s role
The Naperville Park District is a separate taxing body. Its levy helps fund parks, trails, recreation, and community programming. The district’s levy appears as one line item within your overall bill and is combined with the other taxing districts to create your total rate. The specific share can vary year to year based on budgets and assessments.
Exemptions to review
Exemptions reduce the taxable portion of your assessed value. Review them early, especially if you are buying or selling.
- General Homestead Exemption
- Senior exemptions and senior assessment freeze programs where available
- Disabled person or veteran exemptions
Some exemptions follow the owner rather than the property, which means the new owner may need to reapply after a transfer. Check your county assessor for program names, eligibility, and deadlines.
Buyer tips
- Check your county. Confirm whether the property is in DuPage or Will County so you know which billing calendar applies.
- Get the latest tax bill. Ask for the last full-year bill and any proof of payment.
- Review exemptions. Confirm which exemptions are in place and whether they will continue for you.
- Ask your lender about escrow. Clarify the initial escrow deposit and monthly escrow collection, and how upcoming bills will be handled.
- Note special assessments. If the property is in a newer development, ask about any separate assessments or liens that appear on the bill.
Example: If you buy before the county mails the current year’s bill, expect your closing to use the prior year’s bill for prorations, and your lender to pay the new bill later using funds in your escrow.
Seller tips
- Gather documents early. Provide the most recent bill, payment receipts, and a list of current exemptions.
- Confirm your county. DuPage and Will schedules differ, which affects buyer credits and timing of payments.
- Expect prorations. If you paid the current installment, you may receive a credit from the buyer at closing for your prepayment that covers part of their ownership period.
Example: If you already paid a spring installment before closing, the buyer’s closing statement often shows a credit back to you for the buyer’s share of that paid period.
What to verify each year
Because billing dates and rules can change, build in a quick annual check:
- Current year mailing dates and installment due dates from your county treasurer
- Parcel tax history and payment status
- Exemption application requirements and deadlines
- Assessment notices and appeal windows
- Contact details for your county assessor and treasurer for quick questions
Simple timeline
- Jan 1: Assessment date for the tax year.
- Feb to Apr: Assessment notices and appeal periods.
- Nov to Dec: Local taxing bodies adopt levies for the next bill.
- Winter to spring: County treasurer prepares and mails bills. Check your county for exact dates.
- Closings before mailing: Title uses last year’s bill or an estimate to prorate.
- Closings after mailing and payment: Buyer usually credits seller for the buyer’s share of the paid period.
- After closing: Your lender performs an annual escrow analysis and adjusts your monthly payment if needed.
Quick closing checklist
For buyers and sellers, gather these before you sign:
- Last two tax bills and proof of payment
- Parcel number and county of record (DuPage or Will)
- List of current exemptions and any documentation
- Any special assessment disclosures
- Lender escrow estimate and initial deposit details
- Title company’s proration method in writing
If you want a second set of eyes on your documents and a clear plan for prorations, our team can help coordinate with your lender and title company so nothing is missed.
Ready to talk through your situation or plan your next move in Naperville? Reach out to The Jan Mackey Group for local guidance, a smooth closing process, and premium marketing for your sale. Connect with The Jan Mackey Group to Request a Free Home Valuation.
FAQs
Who pays Naperville property taxes at closing?
- Taxes are customarily prorated so each party pays for the time they owned the home, using either the last bill or an estimate depending on whether the current bill has been issued.
How do DuPage and Will County timelines differ?
- Each county sets its own mailing dates, installment schedules, and penalties, so you need to check your specific county’s treasurer each year for the current calendar.
How does escrow for Naperville taxes work with a mortgage?
- Your lender estimates 12 months of taxes, collects monthly deposits, makes payments when bills come due, and completes an annual escrow analysis to adjust your payment if needed.
What happens if the tax bill arrives after I close?
- The title company usually prorates at closing using the last bill or an estimate, and your lender later pays the new bill from your escrow using the credits calculated at closing.
Do exemptions transfer automatically to a new owner?
- Some exemptions are owner-specific and require reapplication after a sale; always confirm requirements and deadlines with the county assessor for your parcel.
How can I confirm if my property is in DuPage or Will County?
- Check your deed or parcel records, ask your title company or agent, or search the parcel number on the appropriate county site to verify county and taxing districts.
