New Hampshire DUI laws set the blood alcohol concentration limit at 0.08% for adult drivers, 0.02% for drivers under 21, and 0.04% for commercial drivers. A first offense is generally a class B misdemeanor with a fine of at least $500 and a license suspension of at least 9 months. New Hampshire’s own statutes use the term DWI rather than DUI. Aggravated DWI carries harsher penalties under a separate statute. The primary source is New Hampshire Revised Statutes Annotated Title XXI Chapter 265-A.
DWI Versus DUI Terminology
New Hampshire law does not use the term DUI in its statutes. The state code refers to the offense as driving while intoxicated, or DWI, under New Hampshire RSA 265-A:2 driving under the influence statute. Many people search using the term DUI because that phrase is common nationally. Readers researching New Hampshire penalties, court records, or license consequences should expect official documents, court forms, and DMV correspondence to say DWI instead of DUI.
What the Law Generally Says
Under Code Section 265-A:2, it is illegal to drive or attempt to drive a vehicle while under the influence of intoxicating liquor or a controlled, prescription, or over the counter drug that impairs the ability to drive. The law also applies when a driver has an alcohol concentration of 0.08% or more. For drivers under the age of 21, that threshold is lowered to 0.02%. The statute also covers operating a boat or an off highway recreational vehicle while impaired.
Code Section 265-A:2 additionally covers combinations of substances. A driver who combines alcohol with a prescription or over the counter drug that impairs driving ability can be charged even if neither substance alone would produce impairment. This means the law generally does not require alcohol specifically. Any natural or synthetic substance that impairs the ability to drive can support a DWI charge under this statute, regardless of whether that substance is legal to possess or use.
Aggravated DWI Explained
Aggravated driving while intoxicated is a separate and more serious offense under Code Section 265-A:3. A charge becomes aggravated when specific factors are present alongside impairment or an excess alcohol concentration. These factors generally include driving more than 30 miles per hour over the posted speed limit, causing a collision that results in serious bodily injury, or attempting to elude a law enforcement officer through actions such as increasing speed or extinguishing headlamps while being pursued.
Aggravated DWI applies to vehicles, boats, and off highway recreational vehicles in the same way that the base DWI statute does. The aggravating factors listed in New Hampshire RSA 265-A:3 aggravated DWI statute apply whether the underlying impairment is based on alcohol concentration or on the influence of drugs. A driver does not need a particularly high blood alcohol reading to face an aggravated charge if one of the other statutory factors applies to their circumstances.
Who New Hampshire DWI Law Applies To
New Hampshire’s impaired driving statutes apply broadly across driver categories, though the legal thresholds differ. Adult drivers operating standard passenger vehicles are held to the 0.08% alcohol concentration limit. Drivers under the age of 21 face a much lower threshold of 0.02%, reflecting the state’s zero tolerance approach to underage drinking and driving. Commercial vehicle operators are held to an even stricter 0.04% threshold under state law.
Commercial drivers face additional consequences beyond the standard penalties. Under Code Section 265-A:23, a person who holds a commercial driver license or was required to have one and is convicted of a DWI offense faces additional penalties and sanctions beyond those imposed on regular drivers. This reflects the higher public safety stakes associated with commercial vehicle operation. The statute also applies to any commercial driver found operating with any measurable alcohol concentration at all.
The law also extends beyond public roads. Boating and operating off highway recreational vehicles while impaired fall under the same core statute as driving a standard vehicle. This means a person operating a boat on a New Hampshire lake or a driver on an OHRV trail can face the same category of impaired operation charge as someone driving a car on a public road, using the same 0.08% threshold for adults.
Administrative Suspension After Arrest
New Hampshire imposes two distinct types of license consequences for a DWI arrest, and confusing them is a common source of reader misunderstanding. The first is an administrative license suspension, which is handled by the Department of Safety separate from any criminal court case. This suspension can begin shortly after arrest based on either a chemical test result or a refusal to test, independent of whether the driver is later convicted in court.
Administrative suspension exists under Code Section 265-A:30 and operates on its own timeline. A driver can be placed under this type of suspension even if the criminal case is still pending or is ultimately resolved in the driver’s favor. This process is designed to address public safety concerns quickly, without waiting for the criminal court process to conclude, and it can be challenged through a separate administrative hearing process.
Court Ordered License Revocation
The second type of license consequence is a court ordered revocation that follows a criminal conviction. Under New Hampshire RSA 265-A:26 license revocation statute, once a person is convicted of a violation of Code Section 265-A:2 or Code Section 265-A:3, the court reports the conviction and the department revokes the person’s license or driving privilege. This revocation is a criminal consequence tied to the conviction itself, not to the earlier administrative process.
These two processes run on separate legal tracks with separate purposes. The administrative suspension addresses the arrest and any test result or refusal, while the court revocation addresses the criminal conviction. A driver can experience both consequences in connection with a single incident, and the length or terms of one process do not necessarily determine the length or terms of the other under New Hampshire law.
First Offense Penalties
A first DWI offense within 10 years is generally classified as a class B misdemeanor in New Hampshire. Under Code Section 265-A:18, this generally carries a fine of at least $500. Secondary reporting citing this same penalty structure notes that with an added penalty assessment, the total financial obligation is commonly cited near $620. Courts may also order probation as part of the sentence, in addition to the base fine amount set by statute.
License consequences for a first offense generally involve suspension periods described across sources as beginning at a minimum of 9 months. First time offenders are also generally required to complete an impaired driver education program before their license can be reinstated. Courts may additionally require submission to alcohol and drug screening, and further evaluation and treatment can be ordered if that screening indicates it is necessary under the applicable program guidelines.
Second and Subsequent Offense Penalties
New Hampshire law imposes substantially harsher penalties for a second DWI offense within 10 years of a prior conviction. Under Code Section 265-A:18, a second offense is generally classified as a class A misdemeanor, a more serious classification than the class B misdemeanor applied to first offenses. The statute generally sets a minimum fine of $750 for a second offense, reflecting the increased seriousness the law assigns to repeat impaired driving conduct.
Prior convictions that count toward a second or subsequent offense are not limited to New Hampshire convictions alone. The statute generally allows reasonably equivalent out of state convictions within the preceding 10 years to count toward the second offense penalty structure. This means a driver with a prior impaired driving conviction from another state can face New Hampshire’s second offense penalties rather than first offense penalties if that prior conviction qualifies under the statute.
Breathalyzer Refusal Penalties
New Hampshire operates under an implied consent framework, meaning a driver who obtains a New Hampshire license has already agreed to submit to chemical testing if lawfully arrested on suspicion of DWI. Refusing that test triggers its own administrative license suspension, separate from any penalty tied to a failed test or a later conviction. This refusal consequence exists specifically to address situations where a driver declines to provide breath, blood, or urine evidence at the time of arrest.
Under current law, the administrative suspension for a first refusal is generally described as running for a period comparable to a failed test result. Senate Bill 620, signed into law on April 20, 2026, increases the administrative license suspension for refusing a breath alcohol or blood test from 6 months to 9 months. This change to Code Section 265-A:14 takes effect on January 1, 2027, and represents a direct legislative response to New Hampshire’s comparatively high test refusal rate.
Readers checking this topic on or after January 1, 2027 should expect the 9 month refusal suspension figure to be the applicable current rule rather than the previous 6 month figure. Because this is a confirmed statutory change with a specific effective date, the distinction between the current rule and the incoming rule matters for anyone trying to understand their actual exposure depending on when an alleged refusal occurs relative to that effective date.
Ignition Interlock Device Requirements
New Hampshire generally requires an ignition interlock device, or IID, as a condition of license reinstatement for DWI offenders. An ignition interlock device is a breath testing unit wired into a vehicle’s ignition system that prevents the engine from starting if it detects alcohol on the driver’s breath. This requirement is designed to allow a monitored return to driving rather than an outright continued suspension for the full underlying period.
According to the NH Division of Motor Vehicles ignition interlock program guidance, a New Hampshire court or the Commissioner of Safety may require installation of this device, and drivers notified of this requirement must contact an approved vendor. First offenders generally face this requirement for a period commonly cited as 1 to 2 years, while aggravated offenses can extend this requirement further. Drivers are generally responsible for all costs connected with installation and ongoing use of the device.
Reinstatement after any DWI related suspension or revocation also generally requires proof of financial responsibility. According to the New Hampshire Department of Safety hearings FAQ, an SR-22 insurance certificate may be required in connection with a DWI conviction. This certificate is a form of proof that a driver carries the state required insurance coverage, and it is generally requested by the DMV as part of the overall reinstatement process alongside the ignition interlock requirement.
Common Misconceptions About Refusal
A common misconception is that refusing a breathalyzer test avoids DWI related penalties entirely. In reality, refusal triggers its own separate administrative license suspension under the implied consent statute, independent of whether a driver is ultimately convicted of DWI in criminal court. Under current law this refusal suspension is generally comparable in length to a failed test suspension, and beginning January 1, 2027 it becomes longer than a first time failed test suspension under Senate Bill 620.
Refusal also does not prevent a criminal DWI case from moving forward. Prosecutors can pursue impairment based on officer observations, field sobriety indicators, and other available evidence even without a chemical test result. A refusal removes one piece of evidence a prosecutor might otherwise use, but it does not eliminate the underlying criminal charge or the administrative consequences tied specifically to the refusal itself.
Common Misconceptions About License Consequences
Another common misconception is that a single license suspension figure describes the entire consequence of a DWI arrest. As described earlier, New Hampshire generally applies an administrative suspension shortly after arrest through the Department of Safety, separate from a later court ordered revocation that follows an actual conviction. These are two distinct legal mechanisms with separate statutory bases, and a driver may become subject to both in connection with the same incident.
This distinction matters because the administrative process and the criminal court process can proceed on different timelines and can produce different outcomes. A driver who successfully challenges an administrative suspension at a hearing has not necessarily resolved the separate criminal case, and a driver whose criminal case results in a lesser charge or dismissal does not automatically undo consequences already imposed through the earlier administrative suspension process. For further background on how these categories interact for a specific situation, see the Disclaimer regarding this general information.
Disclaimer
This article is for general informational purposes only. It is not legal advice. Lawwalls publishes informational content only and does not provide legal services or legal advice.
For legal advice about your specific situation contact a licensed attorney in your state. Laws change and vary by jurisdiction. Verify current rules with official government sources or a qualified lawyer.