DUI Laws in New Hampshire: Penalties, BAC Limits & License Suspension

In New Hampshire, drunk or drugged driving is charged as DWI (Driving While Intoxicated) under RSA 265-A:2 — the state doesn't use "DUI." The per se limit is 0.08% blood alcohol concentration (BAC) for most drivers. And if you took (or refused) a breath or blood test after your arrest, the clock is already running: New Hampshire's Department of Safety gives you only 30 days from the date on your notice to request a hearing challenging the automatic license suspension — miss that window and the suspension locks in whether or not you're ever convicted.

What DWI means in New Hampshire

New Hampshire's impaired-driving law lives in RSA Chapter 265-A ("Alcohol or Drug Impairment"). The base offense, DWI, covers operating a vehicle while under the influence of alcohol, drugs, or a combination, or with a BAC at or above the legal limit. A more serious tier, Aggravated DWI (RSA 265-A:3), applies when certain aggravating facts are present — for example, a very high BAC, driving more than 30 mph over the speed limit, a passenger under 16 in the vehicle, causing a crash with serious bodily injury, or trying to elude police. Aggravated DWI carries steeper mandatory penalties than a standard first offense, including a mandatory ignition interlock device.

BAC limits in New Hampshire

The 0.08% per se limit for adult drivers is a national standard, not unique to New Hampshire. What varies by state — and matters here — are the other thresholds:

• General limit: 0.08% BAC or more (RSA 265-A:2).
• Commercial drivers (CDL): a 0.04% BAC while operating a commercial motor vehicle is the standard threshold, and a DWI conviction generally results in disqualification of commercial driving privileges — confirm the current disqualification period with the Division of Motor Vehicles or an attorney.
• Under 21 (zero tolerance): 0.02% BAC or more is illegal for drivers under 21 — well below the adult limit (RSA 265-A:2).
• Aggravated/high-BAC threshold: a BAC of 0.16% or more is, by itself, enough to charge Aggravated DWI under RSA 265-A:3, even with no other aggravating factor.

These numbers can be amended by the legislature, so confirm the current text of RSA 265-A with the New Hampshire General Court's website or a local attorney before relying on an exact figure.

Implied consent and refusing a chemical test

New Hampshire's implied consent law (RSA 265-A:4) provides that by driving on New Hampshire roads, you've already agreed to submit to a breath, blood, or urine test if an officer has reasonable grounds to believe you were driving impaired. Refusing that test doesn't avoid consequences — under RSA 265-A:14 it triggers its own, separate administrative license suspension, independent of any criminal DWI case:

• First refusal (no prior DWI/Aggravated DWI conviction and no prior refusal): license suspended for 180 days.
• Subsequent refusal (a prior DWI/Aggravated DWI conviction or a prior refusal on record): license suspended for 2 years.

By statute this suspension does not run at the same time as other penalties under this title — it stacks on. And your refusal itself is not off-limits information: it becomes part of the record the state can point to in the license proceeding. If you're arrested, understand what's at stake either way, but this article does not advise refusing or evading testing — that decision carries serious, state-specific consequences you should think through in the moment or discuss with counsel afterward.

The administrative license suspension: you have 30 days to fight it

Separate from the criminal case, New Hampshire's Department of Safety can administratively suspend your license right after arrest — before any judge has decided guilt — based on a failed test (0.08%+, or 0.02%+ under 21) or a refusal. This is sometimes called an ALS (administrative license suspension).

This is the deadline that trips people up: a request for an administrative review or hearing must reach the Department of Safety within 30 days of the date the suspension notice was served (RSA 265-A:31). A request received after that window is denied as untimely. If you were given a temporary license at the time of arrest, treat the countdown as already started.

• Agency: New Hampshire Department of Safety, which handles administrative hearings and reviews for license suspensions (see the Department's official hearings information at dos.nh.gov).
• What to request: either an administrative review or a hearing, submitted in writing, within the 30-day window.
• Suspension lengths if you don't prevail: for a failed test, RSA 265-A:30 sets 6 months for a first violation with no priors, and 2 years if there's a prior refusal, prior DWI/Aggravated DWI conviction, or prior administrative suspension on record.

Because this deadline is short and strict, contact the Department of Safety or a New Hampshire attorney immediately — ideally within days, not weeks, of your arrest.

First-offense DWI penalties in New Hampshire

A standard (non-aggravated) first DWI in New Hampshire is charged as a class B misdemeanor under RSA 265-A:18. Based on that statute:

• Fine: not less than $500 — the statute sets a floor; confirm the current maximum and any added court fees with the court or a local attorney, since these figures can be updated.
• License revocation: not less than 9 months, with the court able to extend it up to 2 years; a portion may be suspended if you complete required screening, evaluation, and education.
• Jail: a first, standard DWI is a class B misdemeanor, which under New Hampshire law does not carry mandatory jail time. Jail exposure rises sharply if the offense is charged as Aggravated DWI or if this is a repeat offense — confirm current mandatory-minimum jail language with the statute or a defense attorney, since aggravating facts change this quickly.
• Ignition interlock device (IID): not required for a standard first offense. It becomes mandatory for Aggravated DWI and for second-or-later offenses (RSA 265-A:36).
• Other requirements: a substance use disorder screening (and evaluation if warranted) and completion of an approved impaired-driver education program are standard conditions attached to a DWI conviction.

Because a first-offense DWI still triggers a court-ordered license revocation on top of any earlier administrative suspension, many people end up dealing with two separate suspension clocks that don't automatically run together.

How prior offenses count: New Hampshire's 10-year lookback

New Hampshire counts a prior DWI or Aggravated DWI conviction as a "prior" for enhancement purposes if it falls within 10 years preceding the date of the current offense (RSA 265-A:18). A conviction older than 10 years generally won't be used to enhance a new charge to second-offense penalties, though it may still be considered in sentencing. Confirm exact dating rules with the statute or an attorney if your prior is close to the 10-year line.

When a New Hampshire DWI becomes a felony

Many first, second, and third DWI/Aggravated DWI charges in New Hampshire are misdemeanors, with penalties escalating each time. A DWI becomes a felony chiefly in these situations:

• Aggravated DWI causing serious bodily injury: when an impaired driver causes a collision resulting in serious bodily injury to another person, the Aggravated DWI is charged as a felony (RSA 265-A:3, RSA 265-A:18) — even on a first offense.
• Fourth or subsequent DWI/Aggravated DWI offense: a fourth-or-later conviction is a felony, carrying indefinite license revocation with no eligibility to petition for reinstatement for a period of years set by statute.
• A death results: causing another person's death while driving under the influence can be separately charged as negligent homicide under RSA 630:3 — a felony, entirely apart from the DWI charge itself, with its own indefinite license revocation.

Other aggravating factors — very high BAC, a young passenger in the car, eluding police, or excessive speed — can push a case into the Aggravated DWI category (which carries mandatory jail and interlock) even on a first offense, but on their own these are typically charged as a heightened misdemeanor rather than a felony. Because these thresholds and their exact consequences depend on the specific facts, verify how they apply to your situation with a New Hampshire defense attorney.

What to do after a DWI arrest in New Hampshire

1. Note the date on your suspension notice immediately. Your 30-day window under RSA 265-A:31 to request an administrative hearing with the Department of Safety starts running from that date, not from when you get around to dealing with it.
2. Request the administrative hearing in writing before the deadline if you intend to contest the suspension at all — this preserves your options even if you settle the criminal case later.
3. Get the paperwork: the arrest report, the suspension/refusal notice, any temporary license you were issued, and your court summons or arraignment date.
4. Talk to a New Hampshire-licensed DWI defense attorney as soon as possible. The administrative suspension and the criminal case are two separate tracks with separate deadlines and separate rules of evidence — a lawyer can help you handle both.
5. Don't skip your court date. Missing arraignment or later hearings can add its own suspension and warrant exposure on top of the DWI matter.
6. Ask about interlock and hardship license options if you need to drive for work, school, or medical needs while your case is pending — availability and terms depend on your specific charge and history.

This article explains general New Hampshire law as of this writing; it is not legal advice, and it does not replace confirming current statutes and deadlines with the New Hampshire Department of Safety, the courts, or a licensed New Hampshire attorney.