How to Appeal Your Property Tax in Colorado: Step-by-Step Guide

Colorado property taxes hit differently than most states. The state reassesses property values every two years, and thanks to a hot real estate market, many homeowners have watched their tax bills jump 30% or more in a single cycle. But here’s what most people don’t realize: you have every right to push back, and the process is more straightforward than you’d expect. County assessors make mistakes — they work with mass appraisal models that can’t account for your specific property’s quirks, like a busy road out front, foundation issues, or a dated kitchen. In Colorado, roughly 40% of property tax appeals result in some reduction. That’s a coin flip worth taking. This guide walks you through the full appeal process, from pulling your assessment notice to showing up at the county Board of Equalization. Whether your home is in Denver, Colorado Springs, or a mountain town, the steps are the same statewide. The whole thing costs nothing but your time, and the potential savings can run into thousands of dollars every year until the next reassessment.

What You Need to Know Before Starting

Colorado’s property tax system works differently from most states, and understanding the basics will make your appeal much stronger. The state uses a two-year reassessment cycle — odd-numbered years bring new valuations based on an 18-month data collection period. Your county assessor determines your property’s “actual value” (what it would sell for on the open market), then applies the residential assessment rate to calculate the assessed value. For 2025-2026, that residential rate is 6.95%.

TABOR — the Taxpayer’s Bill of Rights — adds another layer. This constitutional amendment limits how much revenue governments can collect, which indirectly affects mill levies. But TABOR won’t save you from an inflated assessment. That’s on you to challenge.

The critical number on your assessment notice is the actual value. If your assessor says your home is worth $650,000 and you believe it’s closer to $580,000, that $70,000 difference could mean $400-500 per year in overpaid taxes. Over a two-year cycle, that adds up fast. For a deeper breakdown of how Colorado calculates property taxes, check out our Colorado property tax explainer.

You should also know that filing an appeal is free and carries zero risk. Your assessed value cannot go up as a result of an appeal — it can only stay the same or decrease. There’s literally no downside.

Step 1: Review Your Assessment Notice Carefully

Every Colorado property owner receives a Notice of Valuation by May 1 of reassessment years. This document lists your property’s actual value, the prior value, and basic property details. Don’t just glance at the bottom line — read every field.

Start with the physical description. Check the square footage, lot size, number of bedrooms and bathrooms, year built, and any noted improvements. Assessors pull data from building permits and MLS records, and errors are surprisingly common. A finished basement recorded as unfinished, an extra bathroom that doesn’t exist, or wrong square footage can inflate your value by tens of thousands.

Next, look at the actual value. The assessor arrived at this number using comparable sales from the 18-month study period. If you think the number is too high, you’ll need evidence — which brings us to the next step. Pull up your county assessor’s website and look at the property record card. This is the detailed file the assessor maintains, and it often contains information not shown on the notice itself. In many Colorado counties, you can access this online for free.

Mark the date you received the notice. You have a strict window to file your protest, and missing it means waiting another two years.

Step 2: Gather Comparable Sales Data

Your appeal will live or die on comparable sales — recent transactions of similar properties near yours that sold for less than your assessed value. The assessor used comps to set your value, and you’ll beat them by finding better ones.

Look for sales that occurred during the same 18-month study period the assessor used. For 2025 valuations, that window typically covers July 2022 through December 2023. Properties should be within a half-mile of yours (closer is better), similar in size, age, and style, and in the same neighborhood or subdivision.

Where to find comps:

• Your county assessor’s website — most have a sales search tool
• Zillow, Redfin, or Realtor.com sold listings
• Ask a real estate agent for MLS data (many will pull comps as a favor)
• The county clerk and recorder’s office for deed transfer records

Aim for 3-5 strong comps that support a lower value. If your home has specific issues — like backing up to a highway, sitting on a steep lot, or having deferred maintenance — document those too. The assessor’s model may not have accounted for negative features that reduce your home’s actual market value.

If you’re buying a home and want to understand what your taxes might look like, our homebuyer guide covers what to expect at closing and beyond.

Step 3: File Your Protest with the County Assessor

You must file your protest by June 1 (or the next business day if June 1 falls on a weekend). This deadline is firm — no exceptions, no extensions. Don’t wait until the last day. Submit early so you have time to fix any issues.

Most Colorado counties accept protests three ways:

• Online — Many counties now have electronic filing through their assessor’s website. Denver, Arapahoe, Jefferson, El Paso, and most Front Range counties offer this.
• Mail — Send a written protest to your county assessor’s office. Include your property schedule number, your opinion of value, and your supporting evidence.
• In person — Walk into the assessor’s office and file on the spot. Some offices let you discuss your case informally at this stage.

Your protest should include: your name and contact info, the property address and schedule number, the assessor’s value and your proposed value, and a clear explanation of why you believe the assessed value is too high. Attach your comparable sales data, photos of any property deficiencies, and any other supporting documentation.

Keep it factual and professional. “My taxes are too high” isn’t a valid argument. “Three comparable homes within 0.3 miles sold for $560,000-$590,000 during the study period, while my home was assessed at $650,000” — that works.

Step 4: Present Your Case at the Assessor Hearing

After you file, the assessor’s office will schedule an informal hearing — usually a phone call or in-person meeting. This is your first real shot at getting a reduction, and many appeals are resolved right here without going further.

The hearing is typically with an appraiser from the assessor’s staff, not the county assessor personally. Come prepared with your evidence organized clearly. Lead with your strongest comps and explain the adjustments you’ve made for differences between those properties and yours.

Tips for the hearing:

• Be polite and professional — the appraiser isn’t your enemy
• Stick to market data, not emotional arguments
• If the appraiser shares their comps, take notes and ask questions
• If they offer a partial reduction, you can accept it or continue appealing
• Ask for the decision in writing

If you reach an agreement, the assessor will adjust your value and you’re done. If you disagree with the outcome, you have the right to escalate — and you should, because the next level often produces results when the first hearing doesn’t.

Step 5: Appeal to the County Board of Equalization

If the assessor’s office doesn’t give you a satisfactory result, your next stop is the county Board of Equalization (CBOE). You must file this appeal by July 15. The board is an independent panel — usually three appointed citizens — that reviews disputed valuations.

The CBOE hearing is more formal than the assessor meeting. You’ll present your case, the assessor’s office will present theirs, and the board will make a decision. You can bring new evidence at this stage, so if you’ve found additional comps or documentation since your initial protest, include them.

Prepare a one-page summary of your argument, copies of all your evidence for each board member, and a brief verbal presentation — aim for 10-15 minutes. Boards see dozens of appeals in a day, so being concise and organized will work in your favor.

The board will typically mail their decision within a few days. If you still disagree, you have further options: the state Board of Assessment Appeals (BAA), binding arbitration (for residential properties valued under $5 million), or district court. Most homeowners find resolution by the CBOE stage, but it’s good to know the path continues if needed.

Step 6: Track Your Results and Plan for Next Cycle

Once your appeal is resolved, verify that your property record reflects the corrected value. Check your tax bill when it arrives in January to confirm the reduction carried through. If something looks wrong, contact the assessor’s office immediately.

Keep all your evidence and correspondence. In two years, when the next reassessment hits, you’ll have a baseline to work from. If the market has continued rising, you may need to appeal again — and having your prior case documented makes the process faster the second time.

Set a calendar reminder for late April of the next odd-numbered year so you don’t miss the Notice of Valuation. Many homeowners win one appeal, then forget to check two years later and end up overpaying again.

If you’re also dealing with home maintenance and improvement costs, factor those into your property value assessment. A home that needs a new roof or has aging HVAC is worth less than a fully updated comp down the street.

Common Mistakes to Avoid

The most frequent error is simply missing the deadline. June 1 is firm, and no amount of good evidence will help if you file on June 2. Set reminders, file early, and get confirmation that your protest was received.

Another common mistake is using the wrong comps. Properties outside the study period, in different neighborhoods, or with significant differences in size and condition will weaken your case. Quality matters more than quantity — three strong comps beat ten mediocre ones.

Don’t argue about tax rates or mill levies during your appeal. The assessor only controls the valuation. Tax rates are set by the various taxing districts (school, city, county, fire, water, metro districts), and those are separate battles. If you’re in an area with metro district taxes on top of HOA fees, you might feel the double taxation sting, but the property tax appeal process only addresses assessed value.

Don’t hire a property tax consultant without checking their fee structure first. Some charge a flat fee, others take a percentage of your savings. A percentage deal might sound good, but if they negotiate a $5,000 reduction and take 40%, you’d have been better off spending a Saturday doing it yourself.

Finally, don’t skip the informal hearing and go straight to the CBOE. The assessor’s office resolves many cases at the first stage, and you’ll be better prepared for the board if you’ve already been through the initial review.

Cost and Timeline

From the moment you receive your notice to a final CBOE decision, the process runs about 3-4 months. Most homeowners spend 5-10 hours total on research, filing, and hearings. For a potential savings of $500-2,000+ per year over a two-year cycle, that’s an excellent hourly return.

Frequently Asked Questions

Can my property tax go up if I appeal?

No. Colorado law prohibits your assessed value from increasing as a result of a protest or appeal. The worst outcome is that your value stays the same. There is zero financial risk to filing an appeal, which is why you should always challenge an assessment you believe is too high.

What is the residential assessment rate in Colorado?

For the 2025-2026 tax years, the residential assessment rate is 6.95%. This means your assessed value (what you pay taxes on) equals 6.95% of your property’s actual value. So a home with an actual value of $500,000 has an assessed value of $34,750. Mill levies from various taxing districts are then applied to that assessed value. For full details, see our Colorado property tax guide.

Do I need a lawyer or appraiser to appeal?

No. The vast majority of residential appeals are handled successfully by homeowners themselves. The process is designed to be accessible without professional help. That said, if your property is worth over $1 million or has unique characteristics that make it hard to find comps, a professional appraisal ($300-500) can strengthen your case significantly.

What if I just bought my house — can I still appeal?

Absolutely, and you may have the strongest case of all. If you purchased your home during the study period for less than the assessed value, your purchase price is powerful evidence of actual market value. Bring your closing statement to the hearing. The assessor will have a hard time arguing your home is worth more than what a willing buyer actually paid. Check closing cost breakdowns to understand the full picture of what you paid.

How does TABOR affect my property taxes?

TABOR (Taxpayer’s Bill of Rights) limits how much revenue Colorado governments can collect, which creates downward pressure on mill levies when property values rise sharply. However, TABOR doesn’t prevent your individual assessment from being too high. Even with TABOR protections, an inflated valuation means you’re paying a disproportionate share of the tax burden compared to your neighbors. Appeal the assessment to make sure your share is fair.

What happens if I miss the June 1 deadline?

Unfortunately, you’re stuck with the assessed value for the entire two-year cycle. There is no late filing option and no appeals process outside the statutory deadlines. The only exception would be if the assessor made a factual error (like wrong square footage), which some counties will correct outside the normal appeal window. Set calendar alerts for April of every odd-numbered year so you’re ready when the next notice arrives.

Are metro district taxes included in the property tax appeal?

No. Your appeal addresses only the assessed value set by the county assessor. Metro district mill levies, like all other taxing district rates, are set separately and aren’t part of the appeal process. However, a lower assessed value will reduce the taxes charged by every taxing district, including metro districts. If you’re buying in a metro district area, understand that these additional taxes are permanent and can add $2,000-5,000+ per year on top of regular property taxes.

Can I appeal every reassessment cycle?

Yes. There’s no limit on how many times you can appeal. Many Colorado homeowners file protests every two years as a standard practice, especially in fast-appreciating markets along the Front Range. Even if you won a reduction last cycle, the assessor starts fresh with new data each reassessment period, so your value could jump again.