How to file a property tax assessment appeal (DIY guide)

Step 1: Understand when you can appeal

Appeals are time-bound. You typically cannot just decide to appeal whenever you'd like — you have a specific window tied to your county's assessment cycle:

• Most counties send an assessment notice (or "notice of valuation") annually, sometimes less often
• The notice starts a 30–60 day appeal window in most states
• Miss the window and you wait until the next notice cycle

A few states work differently (e.g., Texas has a May 15 deadline regardless of when the notice arrives; California uses a July–November window). Look up "[your state] property tax appeal deadline" to confirm.

Step 2: Pull your property record card

Start with your county's online property record (often called a "property record card," "appraisal record," or similar). It's usually free. Check every field:

• Square footage
• Bedroom and bathroom count
• Lot size
• Year built
• Condition rating
• Notable features (garage, basement type, pool, etc.)

If the record is wrong (e.g., says 2,800 sqft when your home is 2,550), that alone can be the basis for a correction — often simpler than a full appeal.

Step 3: Build your comparable sales ("comps")

This is the core of the appeal. You want to show the assessor that homes comparable to yours sold recently for less than your assessed value.

Look for comps that are:

• Within 1 mile of your home (ideally same neighborhood)
• Within ~15% of your square footage
• Similar age, condition, and features
• Sold in the past 6–12 months (closer to the assessor's valuation date is better)

Where to find them:

• Zillow, Redfin, Realtor.com — closed sales (not list prices)
• Your county's sales records (free, public)
• Ask a real estate agent friend to pull MLS comps

Aim for 3–5 strong comps. More isn't necessarily better — a few clean comparisons are more persuasive than a spreadsheet of marginal ones.

Step 4: Document issues specific to your property

Beyond comps, document any condition issues that depress value below the "typical" home of your type:

• Deferred maintenance (photos of aging roof, HVAC, plumbing)
• Functional obsolescence (awkward floor plan, small bedrooms, inadequate parking)
• External negatives (busy road, power lines, commercial use next door, flood zone)
• Recent damage (storm, foundation, water)
• Outdated finishes (original 1970s kitchen/bath, old windows)

Photos, repair estimates, and inspection reports strengthen these points. The goal is to establish that your home is not average for its class.

Step 5: File the formal appeal

Most counties have a specific form ("petition for reassessment," "appeal of valuation," etc.). File it before the deadline — late filings are automatically rejected regardless of the merits.

Include in your filing:

• The value you're arguing for (not just "too high")
• Your comps table (property addresses, sale dates, prices, adjustments)
• Property-specific documentation
• Any record-card corrections

Step 6: Informal review first (if offered)

Many counties offer an informal review before a formal hearing — a phone or in-person meeting with an assessor where they may simply agree to reduce your value. Take this seriously. A significant portion of successful appeals are resolved at this stage.

At the informal review:

• Be brief and professional
• Lead with your strongest comp
• Ask "what value would you accept?" rather than arguing
• Get any agreement in writing before ending the call

Step 7: Formal hearing (if needed)

If the informal review doesn't resolve it, your appeal goes to a formal hearing board (often called a "board of review" or "assessment appeals board"). The hearing typically takes 15–30 minutes.

Hearing tips:

• Bring printed handouts of your comps and evidence (3 copies minimum)
• Present your case in 5–10 minutes max
• Answer board questions directly; don't volunteer extra information
• Stay calm; the burden of proof is generally on you, but the board is not adversarial

Common mistakes that sink appeals

• Arguing your tax bill is too high. The board can't change the tax rate, only the assessed value.
• Using list prices, not sale prices, as comps. Only closed sales count.
• Comps that are too different. A brand-new build is not a comp for a 1985 home.
• No specific counter-value. Always tell the board what value you think is right.
• Emotional arguments. "I can't afford it" doesn't change assessed value.
• Late filings. Deadlines are absolute.

When to hire a pro

Services like Ownwell, Protest Your Appraisal, or a local property tax attorney make sense when:

• Your bill is $10,000+ (higher stakes justify the 30–50% contingency fee)
• You don't have time to pull comps and attend hearings
• Your property is unusual (historic, commercial, mixed-use)
• Prior DIY attempts have failed

For typical residential appeals under $7–8K annual tax, DIY is often more lucrative because you keep 100% of the savings — and the savings compound every year you own the home.

Project what a successful appeal would save with our appeal savings calculator.