Is Your Assessment Too High? How to Tell Before Appealing

Read the notice before reacting to the tax amount

Before you react to a larger bill, understand what the notice is telling you. An assessment notice is usually about the assessment (the value your county assigns to your property for tax purposes), while the tax bill is usually built from that assessed value, the tax rate, any exemptions, and local charges. A higher bill can come from more than one of those sources, so your first task is to separate the value from the tax rate and the exemptions.

Read the notice closely and locate each of these items:

• Property address
• Parcel number
• Assessment year
• Fair market value or appraised value (what the property would sell for)
• Assessed value
• Land value
• Improvement value (the value of the building, not the land)
• Exemption status
• Appeal deadline
• Filing instructions

Some offices only let you appeal the assessed value, not the estimated tax. Fulton County, for example, explains that the appeal is about assessed value and that the deadline is printed on the notice. That is the kind of rule you have to confirm locally before you file.

Find the deadline and save proof

Write down the appeal deadline exactly as it appears on the notice, and save a copy of the notice itself. Keep the envelope if the mailing date could matter, and if the website lists a different deadline than the notice, save that page as a PDF or a screenshot so you have a record of both.

Deadlines vary by location, which is why a single national deadline would not be safe to rely on. Fulton County says a property owner may appeal within 45 days of the Notice of Assessment date. Cook County uses township-based reassessment and appeal windows. New Jersey lists a general April 1 filing deadline, with different dates for some reassessment situations and counties.

If the deadline is close, file the basic appeal on time and keep organizing your records afterward. Many local systems let you upload or present evidence after the appeal starts, but the filing deadline is what controls your access to the process, so confirm the local rule before you decide to wait.

Pull the property record

The property record is the official description of your property held in the assessment system. It may list the living area, the lot size, the bedrooms, the bathrooms, the basement, the garage, the year built, the construction type, the condition, and other facts that affect value.

Compare the record against your actual property and look for errors such as these:

• Wrong square footage
• Finished space listed as unfinished, or unfinished space listed as finished
• Wrong bathroom count
• Wrong basement details
• Wrong garage count
• Wrong lot size
• Wrong property class
• An exemption that disappeared

Some offices separate corrections to property characteristics from formal value appeals. Cook County, for example, has a filing type for correcting property characteristics year-round that is separate from an appeal filing. That distinction matters, because fixing a factual error can be a different process than arguing about market value (what your property would sell for).

Compare the property to similar homes

Comparable sales (recent sales of similar properties nearby) help you test whether the assessed value is reasonable. A strong comparable sale is close to your property in location, property type, size, age, condition, lot size, and sale timing. A weak one is too different, too far away, too old, or missing the basic details of the sale.

The California State Board of Equalization says comparable sales are strong documentation for residential property, and that sales closest in time to the valuation date (the date the assessor set the value) are usually the better indicators. It also notes that an appeals board may not consider comparable sales more than 90 days after the county assessor's value date. That timing rule is specific to California, but it shows why the valuation date matters everywhere.

Begin with three to five possible comparable sales, and for each one record the following:

• Address
• Sale date
• Sale price
• Living area
• Bedrooms and bathrooms
• Lot size
• Condition notes
• Distance from your property

Once you have those details, compare each sale against the assessed value shown on your notice.

Check exemptions before filing the value argument

An exemption (a reduction the law allows for people who qualify) can lower your taxable value or your tax bill, depending on local law. As a homeowner, you may qualify for a homestead exemption, a senior exemption, a disability exemption, a veteran exemption, or another local relief program, though eligibility and deadlines vary.

Georgia, for example, says a homeowner is generally entitled to a homestead exemption when the home is owned and used as the legal residence as of January 1, and that counties may offer exemptions more beneficial than the state amount. That is one example, and the exact rule depends on your state and county.

If an exemption is missing or has been removed, that may be a separate issue from the value appeal. Save the records that support it:

• The prior bill
• The current notice
• The exemption application
• The approval letter or denial letter
• Any proof of residence, age, income, disability, or veteran status the local office requires

Build a clean appeal file

A clean appeal file makes your argument easier to review. Keep everything in one folder:

• The assessment notice
• The property record
• Photos
• Comparable sales
• Exemption records
• Prior tax bills
• Emails with the assessor
• Your filing confirmation

As you organize, label each photo with the date and what it shows, put your comparable sales into a table, and for each property record error mark the exact field and write the corrected fact beside it.

The goal is not to hand over a messy pile of documents. It is to show the assessor or the appeal board the assessed value, the specific issue, and the evidence that supports the correction you are requesting.