DUI and DUAC are separate South Carolina offenses that can arise from the same traffic stop, but they focus on different proof. A DUI case asks whether alcohol, drugs, or a combination of substances materially and appreciably impaired your faculties to drive. A DUAC case focuses on whether you drove with an alcohol concentration of 0.08 percent or higher.
The difference can affect which evidence matters most, which legal challenges may apply, and how your defense is developed. The Bateman Law Firm helps drivers in Greenville, Clemson, Spartanburg, and nearby Upstate South Carolina communities review DUI and DUAC charges, chemical testing, police video, license issues, and other evidence.
A 0.08 percent reading is central to a DUAC charge. A DUI charge can still be prosecuted without a 0.08 percent result when the State relies on other evidence to claim that your ability to drive was materially and appreciably impaired.
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What Does DUI Mean in South Carolina? 
South Carolina Code Section 56-5-2930 makes it unlawful to drive a motor vehicle while alcohol, drugs, other substances, or a combination of them impairs your faculties to drive to a material and appreciable degree.
DUI is an impairment-based offense. The State is not limited to a single number from a breath or blood test. Depending on the facts, a prosecutor may rely on evidence such as:
- Driving behavior before the stop
- Statements made to a law enforcement officer
- Odor of alcohol
- Observations about speech, eyes, balance, or coordination
- Field sobriety test performance
- Dash-camera or body-camera video
- Breath, blood, or urine testing
- Witness testimony
- Collision evidence
South Carolina law also sets rules for how alcohol concentration evidence may be considered in a criminal prosecution. If the alcohol concentration is 0.05 percent or less, the law creates a conclusive presumption that the person was not under the influence of alcohol. If the result is above 0.05 percent but below 0.08 percent, the result creates no inference that the person was or was not under the influence of alcohol, although it may be considered with other evidence. At 0.08 percent or higher, the law allows an inference that the person was under the influence of alcohol.
A result below 0.08 percent does not automatically end every DUI case because a DUI charge can involve other evidence of impairment and can involve drugs or a combination of alcohol and drugs.
Read more about South Carolina DUI defenses:
https://duigreenville.com/defenses-to-a-dui-charge/
What Does DUAC Mean in South Carolina?
DUAC stands for Driving with an Unlawful Alcohol Concentration. South Carolina Code Section 56-5-2933 makes it unlawful to drive a motor vehicle in the state with an alcohol concentration of 0.08 percent or higher.
The core difference is the legal theory. DUI focuses on impairment. DUAC focuses on alcohol concentration.
A DUAC prosecution still requires proof. South Carolina law allows a person charged with DUAC to challenge issues that can include:
- Whether the arrest or detention was lawful
- The time between arrest and testing
- Whether the required implied consent rights were provided
- Whether the reported alcohol concentration was 0.08 percent or higher
- Whether the person who administered the test or collected samples was qualified
- Whether the tests and samples were handled under the required procedures
- Whether the breath-testing machine was working properly
The law also permits evidence that may support or question the chemical-test result, including field sobriety tests, evidence of alcohol consumption, driving evidence, video recordings, additional test results, and other evidence concerning the driver’s faculties.
Read more about DUAC in South Carolina:
https://duigreenville.com/what-is-duac/
"John Bateman is my absolute go to peer in the legal field when it comes to questions about DUI. . . . He has an innate ability to convey to clients what really matters in their cases. As a fellow attorney, I highly recommend John to anyone in the SC or NC areas who are looking for... legal representation when facing a DUI charge." "John is an excellent DUI attorney. He has received the same field sobriety test training as all police officers in the State, and also the same training as the people who are the instructors of the police officer training courses on field sobriety tests. He is very passionate about DUI's and I recommend him often to people who are facing serious charges in the upstate area." "Very knowledgeable and thorough in his preparation and representation of his clients. He cares for each of his clients and works extremely hard to achieve results. I highly recommend this lawyer.""He has an innate ability to convey to clients what really matters in their cases."
M. Brock
"An excellent DUI attorney. He has received the same field sobriety test training as all police officers in the State"
P. Hammond
"He cares for each of his clients and works extremely hard to achieve results."
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DUI vs. DUAC: What Must the State Prove?
The shortest way to understand DUI versus DUAC in South Carolina is to ask what the prosecution must establish.
For DUI, the State must prove that you drove a motor vehicle while alcohol, drugs, other substances, or a combination of them impaired your faculties to drive to a material and appreciable degree.
For DUAC, the State must prove that you drove a motor vehicle with an alcohol concentration of at least 0.08 percent.
That difference changes the emphasis of the evidence.
In a DUI case, police video can be highly relevant because it may show how you drove, spoke, walked, followed instructions, or performed field sobriety tests. The defense may also review whether medical conditions, fatigue, footwear, the road surface, lighting, anxiety, or officer instructions affected how your actions appeared.
In a DUAC case, chemical-testing evidence often carries greater weight. The defense may review testing records, machine documentation, operator qualifications, the timing of the test, video from the breath-test site, and compliance with South Carolina testing requirements.
Can DUI and DUAC Be Prosecuted for the Same Incident?
South Carolina law treats DUI and DUAC as separate offenses, but a person may not be prosecuted for both offenses for the same incident.
The law also permits a person who was charged with DUI under Section 56-5-2930 to be prosecuted under the DUAC statute in specified circumstances. The original breath test or collection of other bodily fluids must have occurred within two hours of the arrest, and reasonable suspicion must have existed to justify the traffic stop. The person must receive notice of the intent to prosecute under DUAC at least 30 calendar days before trial.
This statutory provision is one reason that the charge listed on the initial paperwork may not describe every issue that later becomes relevant to the case.
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Are the Penalties for DUI and DUAC Different?
The statutory penalty schedules for DUI and DUAC are substantially parallel. For a first offense, the available punishment changes at higher alcohol concentration levels. South Carolina uses alcohol concentration tiers of at least 0.08 percent but less than 0.10 percent, at least 0.10 percent but less than 0.16 percent, and 0.16 percent or higher for penalty purposes.
Prior DUI and DUAC offenses can also affect later penalties. Under Sections 56-5-2930 and 56-5-2933, qualifying prior violations within the 10 years immediately preceding the latest violation can count as prior offenses.
A conviction for DUI or DUAC also requires enrollment in and successful completion of the Alcohol and Drug Safety Action Program, commonly called ADSAP. South Carolina law also imposes ignition interlock requirements in many DUI and DUAC cases. Under Section 56-5-2990, a first offense generally carries a six-month ignition interlock period, subject to the applicable statutory rules and exceptions.
The exact criminal and driver’s license consequences depend on the charge, alcohol concentration, prior record, test result, and other facts. DUAC should not be treated as simply a lesser version of DUI.
How Implied Consent Can Create a Separate License Case
A DUI or DUAC arrest can create a criminal case and a separate administrative driver’s license matter. South Carolina Code Section 56-5-2950 governs implied consent to chemical testing after an arrest for suspected impaired driving, while Section 56-5-2951 addresses administrative suspensions for refusing testing or having an alcohol concentration of 0.15 percent or higher.
For a driver without qualifying prior convictions or suspensions during the preceding 10 years:
- Refusing a requested chemical test can result in a six-month suspension.
- A reported alcohol concentration of 0.15 percent or higher can result in a one-month suspension.
- The driver has 30 days from the issuance of the notice of suspension to request a contested case hearing.
South Carolina law also provides ignition interlock and temporary alcohol license options in connection with these administrative suspensions, depending on the circumstances.
These administrative consequences are separate from the criminal DUI or DUAC prosecution and can begin before the criminal case is resolved.
Read more about South Carolina implied consent issues:
https://duigreenville.com/implied-consent-greenville-sc/
What Evidence Should Be Reviewed in a DUI or DUAC Case?
The ticket label does not by itself determine the outcome. A careful case review should focus on the evidence and the procedures used to obtain it.
Depending on the facts, useful materials can include:
- Dash-camera and body-camera footage
- Incident-site and breath-test-site video
- Breath-testing records and machine documentation
- Blood or urine laboratory records
- Police reports
- Field sobriety testing notes
- Dispatch records
- Witness statements
- Medical information that may relate to balance, speech, coordination, or testing
- The notice of suspension
- Implied consent advisements
- Any independent testing records
Preserve the documents that you received after the arrest. Write down what you remember about the stop, arrest, testing process, and conversations while those details remain fresh.
Read more about what can happen after a DUI arrest in Greenville:
https://duigreenville.com/after-dui-arrest-in-greenville-sc/
Why the Difference Between DUI and DUAC Matters for Your Defense
A DUI defense may focus heavily on whether the State can prove actual impairment to the degree required by Section 56-5-2930. A DUAC defense may focus more heavily on whether the State can prove an alcohol concentration of 0.08 percent or higher through legally admissible and reliable testing.
Many cases require both types of review because officer observations, field sobriety testing, video evidence, implied consent procedures, and chemical testing can overlap.
Attorney John C. Bateman is a former Army JAG prosecutor. He has completed NHTSA DUI Detection and Field Sobriety Testing training, NHTSA Advanced Roadside Impaired Driving Enforcement training, and the NHTSA DUI Detection and Field Sobriety Testing Instructor’s Course. His background can be relevant when reviewing police decision-making, roadside testing, video evidence, chemical testing, and procedural issues in a DUI or DUAC case.
Learn more about John C. Bateman:
https://duigreenville.com/john-bateman/
Talk With a South Carolina DUI Defense Lawyer
If you were charged with DUI or DUAC in Greenville, Clemson, Spartanburg, or another Upstate South Carolina community, you may have criminal court issues and separate driver’s license deadlines. The Bateman Law Firm can review the charge, police video, chemical-testing records, license paperwork, and the circumstances surrounding the stop so that you can understand the issues in your case and your available options.
Learn more about the firm’s Greenville DUI defense practice:
https://duigreenville.com/greenville-dui-defense-attorney/
To request a free confidential consultation, call (864) 406-3004 or contact The Bateman Law Firm:
https://duigreenville.com/contact/
This article is for informational purposes only and is not legal advice. Reading this article does not create an attorney-client relationship. Consult an attorney about your specific situation.
