Why property taxes go up: a fall 2026 bill checklist

Property taxes can go up because the assessed value, an exemption or a tax rate changed. To find out what happened to your bill, compare the current and prior annual property tax bills for the same home. Check the assessed value, exemptions, tax rates and full-year tax totals. More than one field can change in a year, so the amount due alone cannot tell you the cause. The Illinois Department of Revenue recommends comparing consecutive bills; its office names and rules do not apply nationwide.

What changed between the two bills?

Match the same property and consecutive tax years. Compare annual totals with annual totals, not one installment with a full year's tax. If you pay through a mortgage, use the property tax bills for this comparison rather than the monthly mortgage payments. An escrow account can collect money for insurance as well as taxes. The Consumer Financial Protection Bureau explains how escrow works.

Did the value, exemption or rate change?

An assessed value is the value used in calculating property tax; it is not necessarily today's sale price. A property tax exemption can reduce the value subject to tax when the property qualifies. The type and amount depend on local law. Check the fields shown on your bills and assessment notices, since their labels and the offices responsible vary by location. Illinois identifies value, rates and a removed homestead exemption as possible reasons for a higher bill. A Texas notice of appraised value also lists current and prior values and exemptions.

Possible cause	Compare this field	What it could mean and whom to ask
Value changed	Assessed or appraised value on both bills or notices	A higher value may increase the tax calculation. Ask the local assessment office why it changed. In Illinois, that office is the chief county assessment officer; in Texas, the appraisal district determines value.
Exemption changed	Exemption name and amount, plus the value subject to tax	An exemption may have been reduced or removed. Ask the local office that handles property tax exemptions to check your record and eligibility.
Rate changed	Tax rates and the taxing units listed on each bill	A higher rate can raise taxes without a value increase. Ask the office responsible for tax rates or collections which rate changed. In Illinois, the county clerk's office can explain a rate increase.
Different amounts are being compared	Tax year, full-year total, installment amount and payment record	One installment, an unpaid balance or a mortgage payment is not the same as the annual property tax total. Ask the local tax office about the bill or your mortgage servicer about an escrow payment.

Use the Illinois Department of Revenue's bill-comparison guidance and the Texas Comptroller's explanation of appraisal notices as examples of how responsibilities can differ. Neither state's office names establish the rules where you live.

If your assessed value increased and you want to check whether available market data supports it, start with a free TaxSauce assessment. It helps you compare the assessment with property records and nearby sales. The assessment does not determine whether you can file an appeal or extend a deadline.

Why check a bill in fall 2026?

Fall is a useful time to make this comparison in Texas: taxing units start mailing tax bills in October, according to the Texas Comptroller's payment guidance, checked on November 6, 2026. That mailing schedule is not evidence of a nationwide 2026 tax increase or proof that every account is final.

Receiving a bill does not itself reopen an assessment appeal deadline. In Texas, the appraisal notice explains how to protest a value, while the Comptroller's protest guidance describes filing deadlines and limited late-protest situations. Check your own notice and local rules rather than treating the bill's arrival as a new filing window. Keep the appeal deadline separate from the payment deadline printed on your bill.

Could escrow explain a higher mortgage payment?

Yes. An escrow account holds money your mortgage servicer collects toward expenses such as property taxes and homeowners insurance. Compare your escrow statement with the underlying tax and insurance bills. This shows whether taxes changed, insurance changed or you need the servicer to explain an escrow adjustment. A higher mortgage payment alone does not prove that property taxes rose. If the amounts do not match or you suspect a missed payment, contact the servicer. The Consumer Financial Protection Bureau's escrow guidance explains these checks.

Who should you contact, and what should you keep?

Take the field that changed to the office responsible for it: the local assessment or exemption office for a value or exemption question, and the local tax office or rate-setting authority for a bill or rate question. Contact your mortgage servicer about escrow. Keep both annual bills, assessment and exemption notices, escrow statements, insurance bills and payment records so you can show the change you are asking about. Office responsibilities and appeal rules are local.

If the assessed value looks too high, use your county property tax guide to check the local appeal steps and deadline. TaxSauce can help analyze available market data and organize evidence; paid appeal packet preparation helps you put materials together for your review. You decide what to submit and follow the applicable local filing instructions.