How to Check Your Property Tax Bill for Errors That Cos...

How to Check Your Property Tax Bill for Errors That Cost You Money

About 30% to 60% of property tax assessments contain some type of error. Wrong square footage, a phantom bathroom, an incorrect lot size, or a miscoded property class. These mistakes inflate your assessed value, and you pay extra every single year until someone catches them. That someone has to be you.

TL;DR

Up to 60% of property records contain errors that can inflate your assessment
Common mistakes: wrong square footage, extra bedrooms/bathrooms, incorrect lot size, wrong property class
Check your property record card on your county assessor's website
Errors in property characteristics can add $5,000 to $50,000+ to your assessed value
Many errors can be corrected without filing a formal appeal

Where Errors Hide: Your Property Record Card

Your county assessor maintains a property record card (sometimes called a property data card or property profile) for your home. This document lists everything the assessor uses to calculate your assessed value. You can usually find it on your county assessor's website by searching your address or parcel number.

Here's what to check, line by line:

Square Footage

This is the most common and most expensive error. An extra 200 square feet valued at $150 per square foot adds $30,000 to your assessment. At a 2% tax rate, that's $600 per year in excess taxes.

How to verify: Compare the assessor's square footage against your home's actual measurements. Sources to cross-reference include your purchase appraisal, your home inspection report, your builder's plans, or a measurement you take yourself. Pay attention to whether the assessor is measuring gross living area (GLA) the same way your appraiser did.

Common square footage errors:

Including the garage in living space
Counting a covered porch as finished space
Measuring the exterior footprint instead of interior living area
Including the basement in above-grade square footage

Number of Bedrooms and Bathrooms

An extra bedroom adds $3,000 to $10,000 in value. An extra bathroom can add $5,000 to $20,000. Check that the assessor's count matches reality. A room used as an office shouldn't be counted as a bedroom if it lacks a closet (depending on local definitions).

Basement and Attic

Check whether the assessor lists your basement as "finished" or "unfinished." A finished basement can add $20,000 to $40,000 in value. If your basement is partially finished, make sure it's coded correctly, not as fully finished.

Same goes for attic space. Unfinished attic space should not be counted as living area.

Lot Size

Lot size errors are especially common in rural and suburban areas. A lot recorded as 0.75 acres when it's actually 0.5 acres can make a meaningful difference, particularly in areas where land values are high.

Year Built and Condition

An incorrect year built can affect the depreciation applied to your home. A home built in 1965 gets more depreciation than one built in 1985. If the assessor has the wrong year, you may be under-depreciated.

Condition ratings like "good," "average," or "fair" also affect your value. If your home has deferred maintenance, foundation issues, or aging systems, it shouldn't be rated as "good" or "excellent."

Property Class

Make sure your property is classified correctly. A single-family home taxed as a multi-family or commercial property will be assessed and taxed at a higher rate. This is rare but devastating when it happens.

Features and Amenities

Check for features you don't have:

Swimming pool (not present or removed)
Fireplace (not present)
Central air conditioning (don't have it)
Detached garage or workshop (doesn't exist or was demolished)
Deck or patio (removed or never existed)

How to Check Your Tax Bill for Calculation Errors

Beyond property record errors, your actual tax bill can have mistakes too:

Missing Exemptions

If you applied for a homestead exemption, senior exemption, or veteran exemption, check that it appears on your bill. Sometimes applications get lost or aren't processed in time. Your bill should show the exemption as a line item reducing your taxable value.

Wrong Tax Rate

Your bill should list all the taxing authorities (school district, city, county, special districts) and their individual rates. If you recently annexed into a different city or district, make sure the correct rates are applied.

Expired Special Assessments

Special assessments for things like road improvements or sewer connections are supposed to expire after the project is paid off. Check whether you're still being charged for a special assessment that should have ended.

Math Errors

Multiply your taxable value by the tax rate yourself and compare it to the amount on your bill. It takes 30 seconds and catches more errors than you'd think.

What Each Error Costs You

Error Type	Typical Value Impact	Annual Tax Impact (at 2%)
200 extra sq ft	$20,000 - $40,000	$400 - $800
Extra bathroom	$5,000 - $20,000	$100 - $400
Basement coded as finished (isn't)	$15,000 - $40,000	$300 - $800
Wrong lot size (0.25 acre overstated)	$5,000 - $25,000	$100 - $500
Pool listed (doesn't exist)	$10,000 - $30,000	$200 - $600
Missing homestead exemption	$25,000 - $100,000	$500 - $2,000
Wrong property class	Varies widely	Could be thousands

How to Get Errors Fixed

For Property Record Errors (Wrong Square Footage, Features, etc.)

Document the error. Print or screenshot the property record card showing the incorrect data.
Gather proof. Your purchase appraisal, home inspection report, building plans, or photos showing the actual condition.
Contact the assessor's office. Call or visit and explain the error. Many assessors will correct factual errors without requiring a formal appeal. They may send someone to verify.
Follow up in writing. If the error isn't corrected after your initial contact, send a written request with copies of your evidence. Keep a copy for your records.
File a formal appeal if needed. If the assessor won't correct the error informally, you'll need to file a formal appeal. The evidence for an error correction is straightforward and has a high success rate.

For Tax Bill Errors (Missing Exemptions, Wrong Rates)

Contact the tax collector's office (this may be different from the assessor's office).
Bring your bill and point out the specific error.
If an exemption is missing, bring proof that you applied (your application receipt or confirmation).
Request a corrected bill. Most tax collectors can issue corrections for the current year.

Can You Get a Refund for Past Errors?

In some cases, yes. If you've been overcharged due to an error, many jurisdictions will refund overpaid taxes for one to three prior years. The refund policy varies by state and county. Some states have specific statutes allowing retroactive corrections. Others only fix errors going forward.

It's always worth asking. If you've had the wrong square footage on record for five years, even getting two years of refunds is a significant amount of money.

Prevention: Check Every Year

Make it a habit to review your property record card and tax bill once a year, ideally right after you receive your assessment notice. Catching an error early prevents years of overpaying.

Set a calendar reminder for when assessment notices arrive in your area (typically spring or summer). Take 15 minutes to review the data. It could be the most profitable 15 minutes of your year.

Start With a Free Assessment Check

PropertyTaxFight can help you identify whether your assessment is too high, whether from errors or from an inflated market comparison. Our free assessment check compares your home's assessed value against recent comparable sales in your area.

Check your assessment now and see if your property record matches reality.

Frequently Asked Questions