DUI Laws in New Hampshire

0.08 for drivers 21 and older; 0.02 for drivers under 21.

A first DWI conviction is a class B misdemeanor with a fine of at least $500. The person must undergo alcohol and drug screening (and evaluation and treatment if indicated), complete an approved impaired driver education program and a victim impact panel, and pay program fees. The license is revoked for at least 9 months and up to 2 years; the court may suspend up to 6 months of the revocation if the person complies with screening, treatment and education (an ignition interlock may be required during the reduced period). The court may later reduce the conviction to a violation on motion after one year. Separately, an administrative suspension of 6 months applies for a first test at or above the limit.

DWI becomes a felony in New Hampshire in two main situations: (1) aggravated DWI that causes a collision resulting in serious bodily injury to the driver or another person is a class B felony; and (2) a 4th or later DWI offense, where the prior convictions fall within 10 years, is a felony. A felony 4th offense also brings indefinite license revocation, and the person cannot petition to reapply for at least 7 years.

Refusing a test after arrest leads to an administrative license suspension of 180 days for a first refusal with no prior DWI convictions, or 2 years if the person has a prior DWI conviction or prior refusal. The suspension takes effect 30 days after notice.

10 years. Enhanced penalties apply when a person has one or more prior DWI-type convictions within 10 years before the second or later offense.

On the criminal record, a court may not annul a DWI or aggravated DWI conviction until 10 years after the conviction date. Even after annulment, the record is kept in a permanent file that can be opened for sentencing in a later aggravated DWI case. For repeat-offense penalties, prior DWIs count if they fall within 10 years.