Property Taxes: How They're Calculated, Billed, and Contested

How Local Governments Calculate Your Tax Bill

Property taxes are determined by two moving parts: the assessed value of your home and the mill rate set by your local taxing authority. Understanding both helps you verify whether your bill is accurate.

The assessed value is assigned by a local assessor — a government official or office responsible for estimating the value of all taxable property in their jurisdiction. Assessors typically use one of three approaches: comparing recent sales of similar homes (the sales comparison approach), estimating what it would cost to rebuild the structure (the cost approach), or analyzing rental income potential (the income approach) for investment properties.

Once assessed value is set, the mill rate is applied. One mill equals $1 of tax for every $1,000 of assessed value. For example, if your home is assessed at $300,000 and the local mill rate is 15 mills, your annual tax bill would be $4,500. Local school boards, county commissions, and municipalities each set their own mill rates, and the totals are combined into your final bill.

It's worth noting that many jurisdictions assess property at a fraction of market value — say 80% or 100% — using what's called an assessment ratio. Always check your local rules to understand the relationship between your home's market value and what's actually being taxed.

When and How Your Tax Bill Arrives

Property tax billing cycles differ by location. Some counties bill annually, others semi-annually or quarterly. In many states, tax bills are mailed in the fall and due before the end of the calendar year, though some jurisdictions split payments across the year.

If you have a mortgage, your lender likely collects a portion of your expected property taxes each month as part of your escrow payment, then pays the bill on your behalf when it comes due. If you own your home outright — or your mortgage doesn't include escrow — you're responsible for tracking deadlines and remitting payment directly. Missing a deadline triggers penalties, and prolonged nonpayment can result in a tax lien. For a broader view of annual homeownership obligations, see our annual property ownership responsibilities checklist.

Keep in mind that property taxes are not the only recurring tax tied to assets you own. In some states, personal property taxes also apply to vehicles. Our explainer on how property taxes on vehicles work covers that distinct system.

Exemptions That Can Reduce What You Owe

Most states and counties offer exemptions that reduce the taxable value of your property or cap how much your assessment can rise. Common programs include:

• Homestead exemption: Reduces taxable value for a primary residence. You typically must apply once, and eligibility requires the home to be your principal place of residence.
• Senior exemptions: Available in many states for homeowners above a certain age, often tied to income limits.
• Veteran and disability exemptions: Offered widely for qualifying veterans or homeowners with documented disabilities.
• Assessment caps: Some states limit how much assessed value can rise year over year, protecting long-term owners from sudden tax spikes driven by rising markets.

Exemptions are rarely applied automatically — you need to apply through your county assessor's or appraiser's office. Check your local government's website to confirm what's available and what documentation is required.

Contesting an Assessment You Believe Is Wrong

If your assessment seems too high, you have the right to appeal. The process is more straightforward than many homeowners expect, and a successful appeal can reduce your tax bill for years, not just one cycle.

Step 1 — Review the assessment notice carefully. Look for factual errors: incorrect square footage, extra bathrooms that don't exist, or a lot size that doesn't match public records. Assessors work at scale and errors do occur.

Step 2 — Gather comparable sales data. Look for homes similar to yours — in size, age, and condition — that sold in your area around the time of the assessment. If those homes sold for less than your assessed value implies, that's meaningful evidence.

Step 3 — File a formal appeal before the deadline. Most jurisdictions give homeowners a narrow window — often 30 to 90 days after the assessment notice is issued — to file. Missing it typically means waiting until the next assessment cycle.

Step 4 — Present your case to the appeals board. Many hearings are informal, and you don't need a lawyer, though property tax consultants or attorneys who specialize in appeals can help for higher-value cases. Some work on a contingency basis.

Ignoring an inflated assessment can compound over time. Our article on neglected homeowner duties that create bigger problems later covers why skipping the appeals process is one of the more costly oversights property owners make.

“The property tax system rewards homeowners who pay attention. Assessors deal with thousands of parcels — errors happen, markets shift, and exemptions go unclaimed. The homeowner who reviews their notice and asks questions is often the one who pays the right amount rather than too much.”

— Lincoln Institute of Land Policy, Nonprofit research organization focused on land and tax policy