How to Tell If Your Property Assessment Is Too High

Quick answer: An assessment may be too high when the value implied by the assessment is above what similar properties were actually selling for on the applicable valuation date, or when the assessor’s property data overstates your home.

The number on an assessment notice is not automatically the same as market value. Many jurisdictions assess property at a percentage of market value, while others use additional taxable-value rules. Before deciding that your assessment is wrong, identify what the assessment number is supposed to represent.

Step 1: Calculate the implied market value

Read the notice and local instructions to determine whether the assessed value represents full market value or a stated percentage of it. If your jurisdiction assesses at a fraction of market value, convert the assessment back into an implied market value. That gives you a number you can compare with sales.

Step 2: Check the property record card

Review the assessor’s description of your property line by line. Confirm living area, parcel size, bedrooms, bathrooms, basement finish, garage, exterior features, year built, condition, and improvements. Photograph discrepancies and save supporting documents.

Step 3: Find the best comparable sales

Look for closed sales that resemble your property. Geography matters, but similarity matters too. A home a mile away with the same design, size, school district, condition, and amenities may be more informative than the house next door if that neighboring home is substantially different.

Try to use several comparables rather than one. Note meaningful differences such as renovated kitchens, finished basements, extra garages, waterfront access, larger lots, or major deferred maintenance.

Step 4: Account for condition and defects

An assessor’s model may not fully capture a failing roof, foundation issue, water damage, outdated interior, environmental concern, or other condition problem. Photos, contractor estimates, inspection reports, and appraisals can help explain why your property should not be valued like a renovated comparable.

Step 5: Build a simple value conclusion

Your argument should be easy to follow: this is the assessor’s value; these are the most comparable sales; these are the important differences; and this is the value the evidence supports. Avoid turning the appeal into a complaint about taxes generally. Keep the focus on the valuation issue the decision-maker can actually address.

Build a cleaner property tax case.
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Frequently asked questions

Property tax FAQ

How do I know whether my assessment is too high?

Convert the assessment into the assessor’s implied market value, then compare that value with recent sales of similar properties and verify the property record for factual errors.

Is my neighbor’s lower assessment enough to prove mine is wrong?

Usually not by itself. Neighbor comparisons can be useful, but sales evidence and accurate property characteristics are often stronger indicators of market value.

Should I use asking prices or closed sales?

Closed arm’s-length sales are generally stronger evidence of market value than asking prices because they show what buyers actually paid.

Property Tax Book

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Lowering Your Property Tax in America gives property owners a practical framework for reviewing an assessment, gathering evidence, preparing a filing, and presenting a focused case.

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