The text
Texas Tax Code § 6.17
Sec. 6.17. INTERNET WEBSITE REQUIRED FOR POPULOUS DISTRICTS. An appraisal district established in a county with a population of 120,000 or more shall maintain an Internet website.Added by Acts 2025, 89th Leg., R.S., H.B. 1533, § 4. Effective September 1, 2025.
That is the whole section. It says nothing about what the site contains, how it looks, or how often it changes.
Read it with § 25.01(d)
On its own, § 6.17 could be satisfied by a page with an address and a phone number. Arguably true, and misleading, because the same bill added § 25.01(d) at the identical threshold. That subsection requires the chief appraiser to post the district's completed appraisal records and refresh them weekly.
The two were enacted together and work together. § 6.17 says the site has to exist. § 25.01(d) says it has to carry live data.
Which districts are covered
The test is the population of the county, not the size of the district's staff, budget, or parcel count. A four person office in a county over the line is covered on the same terms as Harris.
The number comes from the most recent federal decennial census, under Government Code § 311.005(3). That means 2020, and it stays 2020 until the 2030 count is certified. Annual estimates and ACS figures do not move the bracket, so a county that has grown past 120,000 since the last census has not picked up a § 6.17 duty in the meantime. Check your county's 2020 decennial number, not its current estimate.
Under the threshold
§ 6.17 does not apply, and neither does § 25.01(d). Running a site voluntarily still puts you inside the other rules. § 26.17 reaches every district's chief appraiser. §§ 25.025 through 25.027 govern what you may post whether or not you had to post anything. ADA Title II reaches any public entity running a site, on a federal clock unrelated to any Tax Code number.
What it means if you are shopping
A district newly covered by § 6.17 is usually not in the market for a brochure site. The binding constraint is the weekly refresh sitting next door in § 25.01(d), and that is a data problem wearing a website costume.
A platform that treats appraisal records as content to be retyped hands you a recurring weekly task that will eventually get missed. One that treats them as data turns the duty into keeping a feed current. Worth putting to any vendor directly. The buyer's guide has the rest of the questions.