New Hampshire DWI Laws and Penalties for Convictions

The penalties you'll face for a DWI in New Hampshire depend on the number of prior convictions and the circumstances of the case. This article explains New Hampshire's DWI laws and the penalties you'll face for a first, second, third, and felony conviction.

New Hampshire's DWI (DUI) Law

In New Hampshire, you can get a DWI (also called “DUI”) for driving or attempting to drive:

• with a blood alcohol content (BAC) of .08% or greater, or
• while “under the influence” of any natural or synthetic substance that impairs a person’s ability to drive—includes impairment from alcohol, prescription drugs, controlled substances, and over-the-counter drugs.

(N.H. Rev. Stat. § 265-A:2 (2025).)

The BAC level that can lead to a DWI is lower for commercial drivers (.04% or more) and drivers who are under the age of 21 (.02% or more). (N.H. Rev. Stat. §§ 265-A:2, 265-A:23 (2025).)

First DWI Penalties

A first DWI within 10 years is generally a class B misdemeanor in New Hampshire and typically carries:

• no jail time
• $500 to $1,200 in fines
• screening for substance abuse disorder (and substance abuse treatment if necessary), and
• a license suspension of nine months to two years.

A court also may order probation as a condition of its sentence. (N.H. Rev. Stat. §§ 265-A:18, 651-2 (2025).)

The penalties are more severe for an aggravated DWI. A misdemeanor aggravated DWI carries:

• 5 days to 1 year in jail
• $750 to $2,000 in fines
• substance abuse evaluation (and substance treatment if necessary), and
• a license suspension of 18 months to 2 years.

An aggravated DWI involving bodily injury is a felony and carries more serious penalties. (See below.) (N.H. Rev. Stat. §§ 265-A:18, 651-2 (2025).)

All first offenders might need to use an ignition interlock device (IID) during the revocation period, and for aggravated offenses, the offender must use an IID for 12 months to 2 years following the revocation period. Before reinstating their licenses, first offenders must complete an impaired driver education program. (N.H. Rev. Stat. §§ 265-A:18, 265-A:36 (2025).)

Second DWI Penalties

A second DWI within 10 years is generally a class A misdemeanor in New Hampshire and typically carries:

• 5 days to 1 year in jail (60-day minimum if the prior was within 2 years of the second)
• $750 to $2,000 in fines
• substance abuse evaluation (and substance treatment if necessary), and
• a license suspension of at least 3 years.

For a second offense within 2 years, 30 days of the 60-day minimum jail sentence must be suspended, conditioned on a substance use disorder evaluation and compliance with a service plan. A court also may order probation as a condition of its sentence. (N.H. Rev. Stat. §§ 265-A:18, 651-2 (2025).)

All second offenders might need to use an IID during the revocation period and must use an IID for 12 months to 2 years following the revocation period. (N.H. Rev. Stat. §§ 265-A:18, 265-A:36 (2025).)

Third DWI Penalties

A third DWI within 10 years is generally a class A misdemeanor in New Hampshire and typically carries:

• 30 days to 1 year in jail
• $750 to $2,000 in fines
• substance abuse evaluation (and substance treatment if necessary), and
• an indefinite license revocation (reinstatement is possible after 5 years).

A court also may order probation as a condition of its sentence. (N.H. Rev. Stat. §§ 265-A:18, 651-2 (2025).)

All third offenders must use an IID for 12 months to 2 years following the revocation period. (N.H. Rev. Stat. § 265-A:36 (2025).)

Felony DWI Penalties

Several circumstances can result in a DWI being elevated to a felony in New Hampshire. Here are some of the most common scenarios.

Fourth or Subsequent DWI Conviction Is a Felony

When an offender has 3 or more prior DWI convictions that occurred within the past 10 years, the current offense will be a felony.

A fourth or subsequent DWI conviction carries a minimum $750 fine, at least 30 days in jail, and indefinite license suspension (reinstatement is possible after 7 years). (N.H. Rev. Stat. § 265-A:18 (2025).)

Felony Charges for DWIs Involving Injuries and Deaths

An aggravated DWI involving an accident where someone is seriously injured is a class B felony that carries a minimum $1,000 fine, at least 35 days in jail (21 days must be suspended, conditioned on completion of substance use disorder evaluation and compliance with service plan), and a minimum 18-month license revocation. (N.H. Rev. Stat. § 265-A:18 (2025).)

Causing the death of another person while driving under the influence is "negligent homicide." Convicted motorists face class A felony charges, up to 15 years in prison, a maximum $4,000 fine, and indefinite license suspension (with reinstatement possible after 7 years). An offender must have an IID for 5 years after reinstating a driver’s license. (N.H. Rev. Stat. §§ 630:3, 651-2 (2025).)

Refusal and Implied Consent

In New Hampshire, all drivers are deemed to have given implied consent to a chemical test of their breath, blood, or urine. When a driver refuses a legal request from a law enforcement officer to take an alcohol or drug test, the Department of Motor Vehicles will suspend the driver's license for:

• 180 days for a first offense, and
• 2 years if the driver has 1 or more prior refusals or DWI convictions.

(N.H. Rev. Stat. §§ 265-A:4, 265-A:14 (2025).)

In some states, the prosecution can’t use a refusal to prove a driver is guilty of DWI. Unlike those states, New Hampshire allows prosecutors to use the fact that a driver refused testing while trying to prove a DWI charge at trial. (N.H. Rev. Stat. § 265-A:10 (2025).)

Underage Drinking and Driving Laws

Many states impose lighter penalties for underage drivers with a BAC under .08 %. But New Hampshire has strict penalties for drivers younger than 21 who have a BAC of at least .02%. The penalties for underage drinking and driving with a BAC of .02% to .08% are the same as a standard DWI (see above), except that all underage drivers will be suspended for at least one year. (N.H. Rev. Stat. § 265-A:18 (2025).)

Getting Help From an Attorney

The penalties for a DWI are serious in New Hampshire. If you've been arrested for driving under the influence, get in contact with a qualified attorney who can help you navigate the legal process.