Texas emissions testing is required in 31 counties, mostly around Dallas, Houston, Austin, and San Antonio

Not all of Texas requires emissions testing to register your vehicle. The state divides into nonattainment areas — regions where air quality doesn't meet federal standards — and the rest of the state. If you live in one of the 31 counties that fall into a nonattainment area, you must pass an emissions test before you can renew your registration. If you live outside those counties, you don't need one.

The counties that require testing are concentrated in four metropolitan areas. The Dallas-Fort Worth region includes Collin, Dallas, Denton, Ellis, Johnson, Kaufman, Parker, Rockwall, and Tarrant counties. The Houston area includes Brazoria, Chambers, Fort Bend, Galveston, Harris, Liberty, Montgomery, and Waller counties. The Austin area includes Bastrop, Caldwell, Hays, Travis, and Williamson counties. The San Antonio area includes Bexar, Comal, Guadalupe, and Wilson counties. Additionally, El Paso, Jefferson, and Nueces counties require testing.

Key Takeaways

  • Emissions testing is required only in 31 Texas counties, all located in or near Dallas-Fort Worth, Houston, Austin, San Antonio, El Paso, Beaumont, and Corpus Christi.
  • You must pass an emissions test before your registration renewal is processed, and the test is valid for two years from the date you take it.
  • Testing facilities are operated by private vendors under contract with the state, and you can find one near you through the Texas Commission on Environmental Quality website.
  • If your vehicle fails the test, you have 60 days to repair it and retest at no additional charge before your registration expires.
  • Vehicles newer than the current year minus 30 years, diesel vehicles over 14,000 pounds, and certain other categories are exempt from testing.

How to learn about your county requires testing

The easiest way is to check the Texas Commission on Environmental Quality (TCEQ) website, which lists all 31 counties by name. You can also call your county tax assessor-collector's office — the same office that handles registration renewal — and they will tell you when ready whether your vehicle needs testing before renewal.

If you're moving to Texas or registering a vehicle for the first time, knowing whether your new county requires testing matters because it affects your renewal timeline. You cannot complete registration renewal without a passing test result if your county is on the list. The test itself takes about 10 to 15 minutes once you arrive at a testing facility.

What vehicles are exempt from emissions testing

Not every vehicle in a nonattainment county has to be tested. Vehicles manufactured in the current year or any of the previous 30 model years are exempt — so a 1995 vehicle tested in 2025 would be exempt, but a 1994 would not. Diesel vehicles that weigh more than 14,000 pounds are exempt. Motorcycles, mopeds, and vehicles with a model year before 1968 are also exempt.

Vehicles registered as antiques, classic cars, or for off-road use only do not need testing. If your vehicle has a salvage title or is registered as non-operational, it is exempt. Check with your county tax assessor-collector if you're unsure whether your specific vehicle falls into an exempt category, because the rules can depend on how your vehicle is titled and registered.

Where to get your vehicle tested

Testing stations are run by private companies under contract with TCEQ. You can find a list of stations in your county on the TCEQ website by entering your county name or ZIP code. The site shows each station's address, phone number, and hours. You do not need an appointment at most stations — you can straightforward drive in during business hours.

Bring your vehicle registration and a valid photo ID. The technician will connect your vehicle to a computer that reads emissions data from your engine. The test measures nitrogen oxides, particulate matter, and other pollutants. The whole process usually takes 10 to 15 minutes. Once you pass, the test result is sent electronically to TCEQ and is available to your county tax assessor-collector when ready.

What happens if your vehicle fails the test

A failed test does not prevent you from registering your vehicle when ready. Instead, you have 60 days from the test date to repair your vehicle and retest at no additional charge. During those 60 days, you can still renew your registration — you just need to show proof that you've scheduled a retest or that you've already retested.

Common reasons for failure include a faulty oxygen sensor, a malfunctioning catalytic converter, a loose or missing gas cap, or an engine light that is on. Many of these repairs are relatively inexpensive. If you're unsure what's wrong, a mechanic can read your engine codes and tell you what needs fixing. Once you repair the problem and retest, the new passing result replaces the failed one in the system.

How long a test result is valid

An emissions test result is valid for two years from the date you take it. This means if you test in January 2025, that result covers you through January 2027. Your registration renewal is tied to your vehicle's birthday — the month and year it was first registered — so your test result must be current on the date you renew.

If your test result expires before your registration renewal date, you will need to retest before you can renew. Plan ahead if your test is approaching its two-year expiration date. You can retest early if you want to — there's no penalty for testing before your current result expires.

Cost of emissions testing

Testing fees vary by county and by testing facility, but typically range from about $15 to $35 per test. Some counties set a maximum fee; others allow facilities to set their own prices. Call ahead or check the facility's website if cost is a concern. The fee is the same whether you pass or fail on your first attempt, and retests within 60 days of a failure are free.

This fee is separate from your registration renewal fee, which your county tax assessor-collector charges. Budget for both when you renew your registration in a nonattainment county.

Frequently Asked Questions

What if I just moved to a nonattainment county and my registration is about to expire?

You must get an emissions test before you renew. Contact your county tax assessor-collector to find out your exact renewal important date, then locate a testing station and schedule a test if needed. Once you have a passing result, you can complete your renewal.

Can I test my vehicle in a different county than where I live?

Yes. You can test at any facility in any nonattainment county. This is useful if you live near a county line or if a facility closer to your work is more convenient. The test result is valid for registration renewal in your home county.

Do I need to test if I'm renewing my registration by mail or online?

Yes. Even if you renew by mail or online, you must have a current passing emissions test result on file before the county will process your renewal. The test must be completed first, then you can renew through whatever method your county offers.

What if my vehicle is too old to test but still runs?

Vehicles older than 30 model years from the current year are exempt from testing. If your vehicle is exempt, you do not need a test to renew your registration, even if you live in a nonattainment county. Your county tax assessor-collector can confirm whether your vehicle qualifies for the exemption.

Can I drive to a testing station if my registration is expired?

Yes. You can drive to a testing facility with an expired registration to get tested. Once you have a passing result, you can then renew your registration. However, you should not drive for other purposes with an expired registration.