Texas DWI Guide: What blood alcohol level is illegal for drivers?

The illegal blood alcohol level in Texas is 0.08% or higher for most drivers. For commercial drivers operating a commercial vehicle, the limit is 0.04%, and for drivers under 21, any detectable alcohol can trigger a DUI/DWI-related offense. Even below 0.08, you can still be arrested if alcohol or drugs impair your “normal use of mental or physical faculties,” so the safest rule is not to drive after drinking. As of November 30, 2025, these thresholds remain the core standards under Texas law.

Texas legal BAC levels at a glance: the illegal blood alcohol level in Texas

Mike, if you manage crews around Houston or across Harris County job sites, you need quick, plain numbers you can trust. Here are the current Texas DWI alcohol concentration thresholds used by police, prosecutors, and courts:

Driver Category	Illegal/Actionable Blood Alcohol Level	Notes
Most drivers (21+)	0.08% BAC (per se DWI limit Texas)	At or above 0.08 creates a per se DWI; below 0.08 can still lead to DWI if impaired.
Commercial drivers (CDL) in a CMV	0.04% BAC	Lower threshold while operating a commercial motor vehicle; separate CDL disqualification rules apply.
Under 21	Any detectable alcohol	Zero-tolerance approach; may be charged under DUI/Minor in Possession and related statutes.

These numbers are commonly called Texas legal BAC limit 0.08, the DWI blood alcohol limit in Texas, and the Houston Texas BAC limit (the law is statewide). If you are a supervisor or parent, understanding these cutoffs helps you make safer choices and protect your license and livelihood.

Key definitions you will see on Texas DWI paperwork

Texas law uses the term “alcohol concentration,” often shortened to BAC. It is defined by grams of alcohol per 210 liters of breath, per 100 milliliters of blood, or per 67 milliliters of urine. A DWI charge can be based on either:

• Per se DWI (0.08 or higher), or
• Loss of normal faculties (officer believes you’re impaired due to alcohol or drugs, even if a test reads below 0.08).

If you’re reading this after a traffic stop in Houston or a nearby county, you’re likely staring at acronyms like “BAC,” “ALR,” and “SOAH.” Below, you’ll find what they mean and what to do next.

What breath or blood numbers mean on the roadside versus in court

It’s easy to assume the number is everything. It isn’t. A roadside preliminary breath test result can contribute to probable cause but doesn’t decide guilt. A formal breath test at a station or an analyzed blood draw can support a per se case at 0.08 or higher, but Texas prosecutors can also pursue a case below 0.08 if other evidence shows impairment (driving behavior, field sobriety tests, bodycam/video, statements, and more). You may feel fine after one or two drinks, yet an officer can still form probable cause to arrest based on the total picture.

For you, this means a reading under 0.08 is not an automatic pass, and a reading over 0.08 is not an automatic conviction. The state must prove its case beyond a reasonable doubt, and test results can be challenged. Think of the number as one piece of a larger puzzle.

Implied consent, test refusals, and immediate license consequences

Texas has an “implied consent” law: by driving on Texas roads, you’re deemed to consent to a breath or blood test after a lawful DWI arrest. Refusing the test can trigger a driver’s license suspension separate from the criminal case. For the statutory foundation and details on chemical testing and consequences, see the Texas statute on implied consent and chemical tests.

ALR basics for first-time arrests:

• If you refuse testing after an arrest, the standard ALR suspension for adults is typically 180 days for a first incident.
• If you take a test and the result is 0.08 or higher, the standard ALR suspension is typically 90 days for a first incident.
• CDL holders face separate disqualification rules and longer consequences; even a first-time ALR issue can jeopardize a commercial career.

Important 15-day deadline: From the date you receive the notice of suspension/temporary driving permit (often a DIC-25 form at release), you usually have 15 days to request an ALR hearing. If you don’t, the suspension often begins on the 40th day after notice. You can make a timely request through the Official DPS portal to request an ALR hearing after arrest. For a plain-language walk-through, see how to request an ALR hearing and protect your license.

If you drive daily to keep projects on schedule, this deadline matters. Missing it can turn one rough night into months of transportation problems and job risk.

Penalties and enhancements linked to BAC and circumstances

Texas penalties escalate based on prior convictions, BAC, and specific facts. Here is a simplified overview:

• DWI First (Class B misdemeanor): Up to 180 days in jail, up to $2,000 fine, possible probation, education programs, potential ignition interlock as a condition of bond or probation, and state fines (currently often $3,000 for a first conviction; higher with certain conditions). A minimum 72-hour jail term exists but is frequently managed through probation in many first-offense cases.
• BAC ≥ 0.15 (Class A misdemeanor): Higher maximum jail (up to 1 year) and fine (up to $4,000); often requires an ignition interlock as a condition of bond or probation.
• Open container in the vehicle can raise minimum jail time (for example, to six days on a first DWI).
• DWI with Child Passenger (under 15): Felony offense with far more severe consequences.
• Repeat offenses: Penalties ratchet up, including possible felony on third or more DWI.
• CDL drivers: Separate CDL disqualification periods can apply, commonly 1 year for a first major alcohol violation while operating a CMV.

For a deeper primer on how these ranges interact with BAC levels and other facts, read this overview of Texas BAC thresholds and related penalties. If your career depends on daily driving, it’s critical to understand both the criminal case and the administrative license track.

Micro‑story: a Houston Friday that got complicated

Mike finishes a 10-hour shift and stops for two pints with a foreman near the Northwest Freeway. On the way home, a broken taillight leads to a stop. The officer smells alcohol, Mike admits to “a couple,” and field sobriety testing follows. At the station, the breath test registers 0.09. He’s booked, released with a temporary permit, and told he has 15 days to act. Monday morning, he’s wondering if this number means he’s guaranteed to lose his license and job. The short answer: a 0.09 is a per se reading, but the case outcome depends on more than the number. The longer answer is below.

Why 0.08 is not a safe harbor—and why 0.08+ is not the end

Common misconception: “If I’m under 0.08, I can’t get a DWI.” In Texas, you can still be charged if alcohol or drugs impair you, even at 0.07 or lower. Conversely, a test at 0.08 or higher does not automatically equal a conviction because tests can be questioned based on instrument performance, timing (rising BAC), medical conditions, sample handling, and more.

You work with tight schedules and safety standards; the law works with standards, too. Those standards allow both sides to challenge evidence. If your BAC result is close to the line, the timing of your last drink, food, mouth alcohol, and the exact procedures used can matter.

Simple, practical BAC ranges and typical effects

Everyone absorbs alcohol differently based on weight, sex, food, medications, and timing. These are general descriptions, not medical advice:

• 0.02–0.04: Mild relaxation; divided attention tasks begin to degrade. CDL drivers can be disqualified at 0.04 in a CMV.
• 0.05–0.07: Reduced coordination and tracking; steering and braking judgment can suffer. You may feel “okay,” but officers may perceive impairment.
• 0.08–0.10: Legal per se DWI threshold for most adults; significant impairment in reaction time, balance, and perception.
• 0.10–0.15+: Clear impairment; higher risk of crashes. At 0.15+, prosecutors often seek enhanced penalties.

As a provider for your family, build in a buffer. If you drink, plan a ride. The difference between 0.07 and 0.09 can be a single drink’s timing—and an entire case’s trajectory.

Houston/Harris County process snapshot: from arrest to resolution

Procedures vary slightly by agency and court, but the general flow in Houston and surrounding counties is similar:

1. Stop and investigation: Officer observes driving, asks questions, and may conduct standardized field sobriety tests. If arrested, you’ll be offered a breath or blood test under implied consent; a warrant may be sought for blood if you refuse.
2. Release and paperwork: You receive charging documents and a temporary driving permit/notice of suspension.
3. ALR hearing request (15 days): File the request to contest the suspension and seek discovery. If timely, your license typically stays valid pending the hearing decision.
4. Arraignment and pretrial: Initial court date, then settings for discovery, motions, and negotiations. Many Houston-area cases take months to resolve.
5. Resolution: Possible outcomes include dismissal, reduction, plea agreement, or trial. Separate license decisions happen through the ALR process at the State Office of Administrative Hearings (SOAH).

Your daily reality—school drop-offs, site meetings, and overtime—depends on your ability to drive. Early, informed steps keep options on the table.

Immediate next steps if you were just stopped or arrested (checklist)

• Mark your calendar: Count 15 days from the date on your temporary permit/notice; that’s your window to request the ALR hearing.
• Submit the request: Use the Official DPS portal to request an ALR hearing after arrest to get started and preserve your right to contest the suspension.
• Learn the process: Read a step-by-step explainer on how to request an ALR hearing and protect your license.
• Collect information: Write down the timeline (drinks, food, medications, stop time, test time). Save receipts or photos that show timing.
• Protect your CDL (if any): Ask about CDL-specific consequences and potential restricted or occupational license options.
• Be cautious with social media: Anything you post can be discovered.
• Review conditions of bond: Comply with any ignition interlock, travel limits, or testing.
• Get qualified legal guidance: Texas DWI law is technical. A knowledgeable Texas DWI lawyer can explain your choices and deadlines.

Data-driven sidebar for the Analytical Planner (Ryan/Daniel)

Numbers that tend to matter in Houston DWI cases:

• 0.08%: per se threshold for most adult drivers; 0.04% for CDL in a CMV; any alcohol if under 21.
• 15 days: time to request ALR hearing after notice; no request often equals automatic suspension beginning day 40.
• ALR lengths (typical first incident): 90 days for a failure; 180 days for a refusal. Longer with priors.
• Enhanced charge often when BAC ≥ 0.15; expect ignition interlock conditions.
• Definition: “Alcohol concentration” measured by breath, blood, or urine; timing and method are frequent litigation issues.

For statutory context on testing, refusals, and warrants, review the Texas statute on implied consent and chemical tests. If you prefer interactive learning, an optional resource is this interactive Q&A: blood alcohol levels and what they mean.

Short, blunt reality check for the Carefree Young Adult (Tyler)

Even a “buzz” can put you over the line or make you look impaired. A first DWI can cost thousands in fines and fees, raise insurance for years, and risk your license, job, or scholarship. Houston rideshares are cheaper than a DWI. If you drink, plan a ride before you go out.

Brief note to the High-Stakes Professional (Jason/Sophia)

Your license status, travel, and professional reputation matter. Ask about ways to minimize public exposure, manage ignition interlock discreetly, and protect professional licenses while your case is pending. Early attention to the ALR timeline and court conditions can reduce disruptions to your work travel and client commitments.

Brief note to the VIP Client (Chris/Marcus)

If privacy is a priority, discuss strategies to limit unnecessary publicity, coordinate appearances, and explore options that may reduce long-term record impact under Texas law when available. No lawyer can promise a result, but informed planning can help you weigh risks and make measured decisions.

Options and defenses commonly explored in Texas DWI cases

Every case turns on its facts. Here are lines of inquiry defense teams often evaluate:

• Reason for the stop: Was there a valid traffic or reasonable suspicion basis?
• Field sobriety testing: Were instructions clear? Any medical or environmental factors affecting performance?
• Breath testing: Instrument maintenance records, operator certifications, observation period, mouth alcohol, and interferents.
• Blood testing: Warrant validity, collection protocol, preservative/integrity of vials, lab chain of custody, method validation, and retesting.
• Rising BAC theory: Timing of last drink and test could mean you were below 0.08 while driving but rose over by the time of testing.
• Video evidence: Bodycam, dashcam, and surveillance can support or undermine impairment claims.

If your job and family depend on your ability to drive, exploring these issues early can shape outcomes—from license status to case negotiations.

Per se DWI limit Texas vs. impairment-based DWI: how prosecutors decide

Prosecutors generally choose one of two tracks—or both: (1) per se at 0.08 or higher, relying on certified test results, or (2) impairment-based, citing total observations even if the result is below 0.08 or the test is refused. In Harris County, discovery often includes reports, video, breath logs, and lab data; prosecutors evaluate the strength of each element. Your decisions in the first 15 days affect the evidence set available at the ALR hearing, which can influence strategy in criminal court.

Under 21 drivers and zero tolerance

Texas’s “any detectable alcohol” rule for under‑21 drivers is stricter than the 0.08 standard. Law enforcement can use the odor of alcohol, admissions, and field evaluations to pursue charges, even if a numeric BAC is not established. Parents in the Houston area should emphasize rides and safe plans: a youthful mistake can ripple into insurance, school, and job prospects.

Commercial drivers: 0.04 and career risk

CDL holders are held to the 0.04 BAC threshold in commercial vehicles and face separate federal and state disqualification rules. A single DWI-related incident can trigger a 1‑year CDL disqualification, and more with hazardous materials endorsements. If you depend on your CDL, treat every deadline as mission‑critical. Consider occupational and route-planning options if allowed, and confirm whether any ignition interlock requirement affects fleet policy.

Houston context: courts, timelines, and everyday life

In Harris County and nearby jurisdictions, first settings may be weeks out, and full resolution can take several months or longer depending on discovery and lab turnaround. During that time, the court may impose conditions such as ignition interlock or abstention requirements. For working parents and supervisors, day‑to‑day logistics—childcare, shift coverage, and site visits—need planning. Treat the case like a project: task list, deadlines, documentation, and regular status checks.

Resources if you want to go deeper

• Statutory background on testing and refusals: Texas statute on implied consent and chemical tests.
• Practical steps for protecting your license after arrest: how to request an ALR hearing and protect your license.
• Penalty ranges, enhancements, and common conditions: overview of Texas BAC thresholds and related penalties.

Top FAQs about the illegal blood alcohol level in Texas

Does 0.08 mean I will automatically be convicted of DWI in Texas?

No. A 0.08 or higher is the per se threshold, but the state still must prove the case beyond a reasonable doubt. Test procedures, timing, instrument performance, and other evidence can be challenged. Outcomes vary by facts and jurisdiction.

What happens to my license after a DWI arrest in Houston?

You typically receive a temporary permit and a notice that your license will be suspended unless you request an ALR hearing within 15 days. If you request on time, the suspension is usually delayed until the hearing decision. Standard first-offense ALR suspensions are commonly 90 days for a failure and 180 days for a refusal.

Is 0.04 the limit for commercial drivers even when I’m off duty?

The 0.04 threshold applies when you are operating a commercial motor vehicle. Off duty in a personal vehicle, the general 0.08 standard applies, though any alcohol-related incident can still affect your CDL under separate rules. A single incident can lead to a 1-year disqualification for CDL holders.

How long does a DWI stay on my record in Texas?

A DWI arrest and case history can remain accessible on criminal and driving records. Texas allows limited sealing (nondisclosure) in some circumstances for certain first offenses after waiting periods, but rules are specific and fact-dependent. Ask a qualified Texas DWI lawyer about eligibility and timing.

Can I refuse a breath or blood test in Texas?

Yes, but refusing after a lawful arrest generally triggers a longer ALR suspension than failing a test, and officers may seek a warrant for a blood draw. Texas’s implied consent law governs these consequences, and judges in Harris County regularly review warrant requests in DWI investigations.

Closing guidance: why acting early matters

Texas DWI law turns on details: the stop, the timeline, the test, and your deadlines. The illegal blood alcohol level in Texas is clear—0.08 for most drivers, 0.04 for CDL in a CMV, and zero tolerance for those under 21—but the path forward depends on how quickly you respond and how well you document your side of the story. Protect your license by meeting the 15-day ALR deadline, keep good records, and consider speaking with a qualified Texas DWI lawyer who can evaluate your specific situation. In high-stakes roles where family income and job stability are on the line, early, informed action is the most practical way to avoid worst‑case outcomes.

Butler Law Firm - The Houston DWI Lawyer
11500 Northwest Fwy #400, Houston, TX 77092
https://www.thehoustondwilawyer.com/
+1 713-236-8744
RGFH+6F Central Northwest, Houston, TX
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