How Do I Check If Collin CAD Has My McKinney Home's Square Footage Wrong Before My Next Tax Bill Shows Up?
How do I check if Collin CAD has my McKinney home's square footage wrong before my next tax bill shows up? Pull your property record online at collincad.org, compare the listed square footage to your builder plans or a recent appraisal, and file a correction request if the numbers don't match.
Property taxes in McKinney and across Collin County are calculated using the square footage on file with the Collin Central Appraisal District, not necessarily the square footage you think your home actually has. If that number is inflated, even by a few hundred square feet, you could be overpaying every single year without ever knowing it. This kind of error is more common than most homeowners realize. It can happen when a builder submits early plans that later get revised, when an addition or converted garage gets recorded incorrectly, or when a data entry mistake during a mass reappraisal simply never gets caught. Because Collin CAD reassesses values annually and property owners have a limited window each spring to formally protest, waiting until your tax bill lands in the mail is often too late to fix the current year's assessment. Checking now, well before notices go out, gives you the time you need to gather documentation, request a correction, and potentially lower your taxable value before it's locked in. This is especially worth doing if you've never personally compared your recorded square footage to your actual floor plan, or if you bought a resale home in an established McKinney neighborhood where records may not have been updated in years. Below, we'll walk through exactly where to look, what discrepancies actually matter, and what to do if you find one.
Start With Your Collin CAD Property Record
Every home in McKinney and the rest of Collin County has a public record on the Collin Central Appraisal District website. Search by your address or CCAD property ID to pull up your official record, which lists the appraised value, lot size, year built, and the recorded living area square footage the county uses to calculate your tax bill.
Write down that square footage figure exactly as it appears. This is the number that matters for tax purposes, regardless of what your listing photos, mortgage documents, or memory tell you.
Compare It To Your Actual Floor Plan
Next, line up that CCAD number against a real source of truth for your home's actual size. Good sources include:
- Your builder's original floor plan, if you bought new construction in a neighborhood like Trinity Falls or Painted Tree
- The square footage listed on your closing documents or original appraisal
- A measurement from a licensed appraiser if you've had one out recently
- Your own measurements using the ANSI standard method, measuring exterior walls room by room
If you live in an established neighborhood such as Stonebridge Ranch or Craig Ranch and purchased a resale home, don't assume the CCAD figure was ever verified against the physical structure. These records get carried forward from prior owners and prior appraisal cycles, and errors can persist for years without anyone catching them.
What Kind Of Discrepancy Actually Matters
A difference of 10 to 20 square feet is usually just rounding or measurement method and isn't worth pursuing. But if your CCAD record shows meaningfully more square footage than your home actually has, that's a real problem, because Collin County calculates your appraised value in part using price per square foot for your area.
This is exactly why price per square foot varies so much between McKinney neighborhoods — the county is applying a rate to whatever square footage is on file, so an inflated number gets multiplied into a real dollar overpayment on your tax bill every year it goes uncorrected.
Common Causes Of Square Footage Errors
- A garage conversion or bonus room that was counted as living space but isn't heated/cooled
- Builder plan revisions that were submitted to the county before final construction changes
- Second-story bonus rooms or flex spaces recorded inconsistently
- Simple data entry mistakes during mass appraisal updates
How To File A Correction With Collin CAD
If you find a discrepancy, contact Collin CAD directly and request a correction to your property record. You'll typically need to provide documentation, such as a copy of your floor plan, a recent appraisal, or photos and measurements showing the actual layout.
Because this can affect your appraised value, it's worth doing before the annual protest deadline each spring, not after you've already received a tax bill based on the incorrect figure. If you're also watching your overall tax exposure, especially in newer developments, it's worth reviewing how MUD and PID tax rates factor into your total bill, since square footage errors and district tax rates can compound into a bigger overpayment than either issue alone.
Why This Matters Beyond Just Taxes
An incorrect square footage figure doesn't just affect your annual tax bill. It can also show up in county records that title companies, appraisers, and even future buyers reference during a sale. Catching and correcting it now protects both your current tax liability and the accuracy of your home's public record long-term, whether you're staying put in McKinney for years or planning to sell.
Frequently Asked Questions
Does a square footage error automatically lower my property taxes if corrected?
Not automatically, but if your recorded square footage is reduced, it typically lowers your appraised value, which can reduce your tax bill. Collin CAD will reassess the value based on the corrected data.
How often does Collin CAD update square footage records?
Records are generally only updated when a permit is filed, a new construction is added to the tax roll, or a homeowner requests a correction. Routine annual reappraisals usually adjust value, not the underlying square footage figure, unless someone flags an error.
What if I don't have my original floor plan?
You can request a copy from your builder, check your closing or appraisal documents, or measure the home yourself using exterior wall measurements. A licensed appraiser can also provide a documented measurement if needed.
If you're not sure where to start, send me your CCAD property ID and I'll pull your recorded square footage against your actual floor plan for free. I'm Jane Clark with Keller Williams McKinney, and I help homeowners across McKinney and Collin County catch exactly these kinds of tax record issues before they turn into an overpayment.
