Understanding Property Taxes in Williamson County: Rates, Authorities, and Exemptions Explained

Property taxes are one of the most significant recurring costs of homeownership in Texas—and Williamson County is no exception. Whether you're a first-time buyer or long-time homeowner, understanding how these taxes are calculated, who sets them, and what exemptions you may qualify for can make a major impact on your bottom line.

Let’s break down how property taxes work in Williamson County, including who collects them, how much you can expect to pay, and how to reduce your tax bill.

Who Collects Property Taxes in Williamson County?

Property taxes are assessed and collected by multiple taxing authorities, each responsible for a portion of the services you receive. The amount you pay is based on the combined tax rate of all these entities, multiplied by your home’s assessed value (minus any exemptions).

In Williamson County, your total property tax bill could include taxes from:

• Williamson County (general government and road & bridge fund)

• City (if your home is within a city’s limits)

• School District (ISD, a major portion of your tax bill)

• Special Districts like:

  • MUDs (Municipal Utility Districts)

  • WCIDs (Water Control & Improvement Districts)

  • ESDs (Emergency Services Districts)

  • Drainage or Road Districts

Each entity sets its own tax rate, typically expressed as a percentage or dollar amount per $100 of assessed value.

What Are the Current Property Tax Rates?

As of 2024–2025, the base Williamson County property tax rate is:

• County General Rate: 0.333116

• Road & Bridge Rate: 0.044329

• Combined County Rate: 0.377445 per $100 of valuation

That means on a $400,000 home (with no exemptions), the county portion of your tax bill alone would be about $1,509 annually.

But that’s just the starting point. Once you add in school districts (often around 1.0%–1.2%), city taxes (0.4%–0.6%), and any special districts, the total rate can rise significantly.

Typical Total Tax Rates:

• Round Rock ISD (no MUD): 1.9%–2.1%

• Georgetown or Leander city limits: 2.0%–2.3%

• Liberty Hill ISD + MUD: up to 2.5%

• Unincorporated areas with minimal services: 1.4%–1.6%

• Sun City (Georgetown): ~1.7%–1.8%

That range means a difference of $4,000–$10,000 per year on a $500,000 home depending on location.

Areas with the Lowest Property Taxes

If you're looking to reduce your ongoing housing costs, some parts of Williamson County offer significantly lower combined tax rates—especially unincorporated areas that fall outside of city limits and avoid MUD or ESD fees.

For example, the City of Thorndale currently has one of the lowest combined rates in the county, at around 0.50%, due to limited overlapping jurisdictions. Some rural areas and older communities, like parts of Sun City in Georgetown, also benefit from low rates because infrastructure is already in place and paid off—meaning no added MUD or WCID tax.

While these low-tax areas may save you money, they often have fewer services or amenities compared to homes within cities or new developments.

Understanding the Appraisal Process

Property values in Texas are assessed annually by the county appraisal district (in this case, WCAD – Williamson Central Appraisal District). They determine your home’s market value, which is then used to calculate taxes. If you believe the appraised value is too high, you can file a protest.

The taxable value is calculated as:

Assessed Market Value – Exemptions = Taxable Value

That number is then multiplied by the combined tax rate to determine your bill.

Common Property Tax Exemptions

Thankfully, there are several exemptions that can lower your taxable value—and ultimately, your tax bill. Some of the most common in Williamson County include:

1. Homestead Exemption

Reduces your taxable value on a primary residence.

• County Homestead: $5,000 minimum (often higher)

• School District Homestead: $100,000 (as of 2023 reform)
  You must own and occupy the home as your primary residence by January 1 of the tax year.

2. Over-65 Exemption

Homeowners aged 65+ can receive additional reductions on school and county taxes—and freeze school taxes altogether. This is in addition to the standard homestead exemption.

3. Disabled Person Exemption

Available to those with disabilities certified by the Social Security Administration or VA.

4. Veteran or Surviving Spouse Exemptions

Veterans with a disability rating may receive a partial or full exemption, depending on rating. A 100% disabled veteran is typically fully exempt from property taxes in Texas.

You can apply for these exemptions through the WCAD website at wcad.org.

Final Thoughts

Property taxes in Williamson County can vary significantly depending on where you live, what taxing entities apply, and whether you qualify for exemptions. While the base county rate is fairly modest, overlapping jurisdictions—especially MUDs and school districts—can push your total tax burden well above 2% in many areas.

Before buying a home, it’s essential to research the total tax rate for the specific address, not just the city or zip code. And if you're already a homeowner, make sure you're not missing out on valuable exemptions that could save you hundreds—or even thousands—every year.

Have questions about how property taxes could affect your purchase or sale? I’m happy to run the numbers and help you make a smart, tax-savvy decision.