What Is Notice of Assessment?
An official document from the county assessor informing a property owner of their property's assessed value for the upcoming tax year.
Detailed Explanation
How It Varies by State
Mailed when value changes or a new exemption is applied. Includes property details, appraised value, and protest instructions. 30-day protest window.
Shows just value, assessed value, exemptions, and proposed taxes from all taxing authorities. 25-day appeal window.
Published by assessor. Grievance Day allows property owners to file formal challenges.
Mailed when township reassessment occurs. Cook County provides online lookup of assessment changes.
Mailed when the value changes. Starts a 45-day window to appeal, filed with the county Board of Tax Assessors, notably longer than the 25-30 day windows common elsewhere.
Common Misconceptions
Myth:If I did not receive a notice, my value did not change
Reality:Some states only mail notices when values change. Others publish the roll online. Check your county assessor's website annually even if you do not receive a physical notice.
Myth:The notice is the same as my tax bill
Reality:The notice shows the assessed value. The tax bill, which comes later, shows the actual amount you owe after all rates and exemptions are applied.
Myth:The property details on the notice must be accurate
Reality:Data errors are common. Always verify the square footage, lot size, bedroom/bathroom count, and property class listed on your notice against your actual property.
Myth:I can wait until my tax bill arrives to decide whether to appeal
Reality:By the time your tax bill arrives, the appeal window triggered by your notice of assessment has usually already closed. Act on the notice itself, not the bill that follows it months later.
Impact on Your Tax Bill
If your notice shows 2,400 square feet but your home is actually 2,100 square feet, that 300 square feet of error could inflate your value by $30,000 to $60,000 depending on your market. In a state with 2% effective tax rate, that translates to $600 to $1,200 per year in excess taxes from a simple data error.
Frequently Asked Questions
Is the notice of assessment the same as my property tax bill?
What should I check first when I get my notice of assessment?
What if my county never mailed me a notice?
Can I appeal after my tax bill arrives instead of when I get the notice?
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