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Last updated: January 2, 2025

What to Know About Ignition Interlocks

A state-by-state breakdown of ignition interlock laws

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Maya Afilalo Headshot MBA Photo
Maya Afilalo
Managing Editor & Industry Analyst
Kate Romain Bio Pic
Kate Romain
Staff Writer

Driving under the influence of alcohol or drugs can result in loss of driving privileges. Before restoring driving privileges, local authorities often require individuals convicted of DUI to install an ignition interlock in their vehicle. The point of the interlock is to discourage alcohol-impaired driving by preventing drivers with a high BAC (blood alcohol content) from starting their vehicles. Here’s what you need to know about using one.

Editor’s note: We have updated this page with the latest laws, data, and requirements regarding ignition interlocks.

What Is an Ignition Interlock?

An ignition interlock (often simply called an interlock) is a small breathalyzer device for your car.

Before starting the car, the driver must breathe into a mouthpiece on the interlock. The interlock measures the amount of alcohol in the driver’s breath and, if it’s too high, prevents the engine from starting. Drivers with DUIs are often required to install an interlock in their car, requiring a blow pattern before the car will start.

How Does an Ignition Interlock Work?

Ignition interlocks come with a preset threshold for blood alcohol concentration (BAC). If the interlock registers a BAC over that threshold when the driver breathes into the mouthpiece, the vehicle will not start. If the driver’s BAC is below the preset limit, the vehicle will start. Typically, an interlock can detect any alcohol the driver has consumed within the last 12 to 24 hours.

FYI

The exact BAC limit that will prevent you from starting your vehicle varies by state, but is typically around 0.02 percent. See the table below for more details on the interlock BAC limit in your state.

The method required for blowing into the mouthpiece differs depending on the device. The following are most common.

  • Blow-inhale-blow: The user blows into the mouthpiece for a few seconds, inhales, and then blows into the mouthpiece again.
  • Straight blow: The user simply blows into the mouthpiece with force.
  • Blow and hum: The user blows into the device for several seconds while humming at the same time. The device uses the humming to verify that a person is blowing into the mouthpiece.

Interlocks require service and calibration at regular intervals, typically every 30, 60, or 90 days, depending on the state. An authorized service center can perform the required maintenance. In many cases, at the time of calibration, the interlock sends a log of results to local authorities for review.

Some interlocks come equipped with extra features, like a camera or real-time reporting. The required features vary by state.

Often, an interlock requires random retests after you start your vehicle. You should not complete a retest while driving; instead, pull over when your device alerts you. An interlock will never stop your car while you are driving.

The goal of interlocks is to decrease alcohol-related crashes and fatalities and to reduce DUI re-arrest rates. According to the NHTSA, states that require interlocks experience 26 percent fewer fatal alcohol related crashes than states that do not. They also found states that require interlocks only for repeat offenders experience 20 percent fewer alcohol related crashes.1

Where Can I Get an Interlock?

You will need to go to an authorized service center to get an interlock device. A number of companies lease them, such as LifeSafer, SmartStart, and Intoxalock. Interlock companies allow you to search their websites for authorized service center locations near you. Choose an interlock provider based on convenience, price, and required features.

How Much Do Interlocks Cost?

An interlock typically costs $60 to $90 per month, depending on the type of vehicle, state, interlock term length, and any additional required features (like a camera or GPS). You may also have to pay a one-time installation fee of $75 to $150. Providers lease ignition interlocks, rather than sell them outright, because you’ll need one only for the duration the court requires.

FYI

Expect your car insurance rates to increase if you receive a DUI. Learn more about how DUIs affect auto insurance rates.

How Do I Install an Interlock?

A state-certified provider must install the interlock for you. Many local auto service shops offer interlock services. The company from which you lease the interlock will help you locate a service provider.

When the provider installs the interlock, they will show you how to use it properly. Anyone who drives your car regularly should also receive training on how to use the interlock. Improperly using an interlock can result in test fails, which show up on your driving record.

What Is a DUI Interlock Program?

A DUI interlock program is a state-mandated plan to get drivers back on the road safely after DUI convictions. Programs vary by state but usually contain the same general elements:

  1. You go to an authorized service provider and pay to have the interlock installed.
  2. You bring your vehicle back to the provider for regular calibration.
  3. The device reports your results to monitoring agencies, which check your compliance.
  4. Sometimes you need to obtain a special drivers license. For example, in Delaware, if you are a first-time offender, you can often apply for a conditional license after completing a state-approved education or treatment program.

    5. 2

  5. Depending on your state, you may need to complete extra steps. For example, some states require you to complete an alcohol education course, undergo counseling or a psychological evaluation, pay fees, or retake your driver’s tests.
  6. After you complete the program, bring your vehicle to the service center so that a technician can remove the device.

FYI

In addition to installing an interlock device, a DUI interlock program may require you to undergo counseling, pay fees, and retake your driver’s tests.

What Are the State Laws Regarding Ignition Interlocks?

In all states, the maximum legal BAC while driving is 0.08.3 However, state laws differ around driving privileges after a DUI and the circumstances under which you need to install an interlock.

After a DUI conviction, the Department of Motor Vehicles (DMV) will usually suspend your license. In some states, you can drive during the suspension period if you install an interlock. In other states, you cannot drive during the suspension period; instead, you need to wait for the DMV to reinstate your license, which is often conditional on installing an interlock.

Check out the chart below for more details on interlock laws by state.4

State Time DUI stays record Increased BAC threshold Increased BAC penalty Administrative license suspension on first offense5 Limited driving privileges during suspension When are ignition interlocks mandatory? Term used to describe interlock Time required to use interlock
Alabama 5 years 0.15 6 months of additional interlock requirement 90 days Must apply for hardship license Mandatory for high BAC (0.15 and above) and repeat convictions; highly incentivized for first convictions Ignition interlock device (IID) First offense, BAC under 0.15: 6 months

First offense, BAC over 0.15: 2 years

Second offense: 1 year

Third offense: 3 years

Fourth and subsequent offenses: 4 years
Alaska Lifetime None None 90 days After 30 days Mandatory for all convictions IID First conviction: 6 months

Second conviction: 12 months

Third conviction: Variable at the court’s discretion
Arizona Lifetime 0.15 and 0.2 0.15 or above: 6 months of additional interlock requirement, minimum 9 days jail time

0.2 or above: Minimum 14 days jail time

 90 days After 30 days Mandatory for all convictions Certified IID Second or third offense, or offense in which you are driving on a suspended or revoked license due to a prior DWI offense, or you endanger a child with your drunk driving: 1 year after the license suspension/revocation ends or the date of the conviction, whichever is later
Arkansas 5 years None None 6 months Yes Mandatory for all convictions IID First offense: 6 months

Second offense: 1 year

Third offense: 2.5 years

Fourth offense: Lifetime interlock required
California 10 years 0.15 “Heightened consideration” (at court’s discretion) 6 months After 30 days Discretionary; mandatory for all convictions in Alameda, Los Angeles, Tulare, and Sacramento counties (pilot project extended) IID First offense: 6 months

Second offense: 1 year

Third offense: 2 years
Colorado 10 years 0.15 Interlock for 1 year 9  months Yes Mandatory for high BAC (0.15 and above) and repeat convictions; highly incentivized for

first convictions

 IID First offense, BAC >0.15: 8 months

First offense, BAC <0.15: 2 years

Second offense: 2 years
Connecticut 10 years None None 45 days Yes Mandatory for those with BAC of 0.8 or higher IID First offense: 1 year

Second offense: 3 years
Delaware Minimum of 5 years 0.15 and 0.2 0.15 to 0.19: 6 months of additional license suspension (18 months total)

0.2 or above: 12 months of additional license suspension (24 months total)

 1 year No Mandatory for those with BAC of 0.15 or higher IID First offense: 12-23 months

Second offense: 16-28 months

Third offense: 21-33 months

Fourth offense: 54 months
District of Columbia 15 years 0.2, 0.25, and

0.3

 0.2 to 0.24: Additional 10  days of mandatory jail time

0.25 to 0.29: Additional 15 days of mandatory jail time

0.3 or above: Additional 20  days of mandatory jail time

 6 months Yes Mandatory for all convictions IID First conviction: 6 months

Second conviction: 1 year

Third and subsequent convictions: 2 years

Third conviction within 5 years: Lifetime
Florida 75 years 0.15 and 0.2 Additional penalties for BAC 0.15 or above while under age 18

First offense: $1,000-$2,000 fine, up to 9 months of jail time, 6-month minimum interlock requirement

Second offense: $2,000 to $4,000 fine, up to 12 months jail time, 2-year minimum interlock requirement

Third and fourth offenses: $4,000 minimum fine, plus the above penalties

 6 months for DUI, 12 months for refusal After 30 or 90 days Mandatory for all high-BAC offenders IID

First conviction <0.15 or a minor in the vehicle: 6 months

Second conviction: 1 year

Third conviction: 2 years
Georgia 5 years 0.15 0.15 BAC on first offense receives same sentence as those convicted of second offense: $1,000-$3,000 fine, 6-12 months of jail time (judge may suspend all but 15 days), 5-year license revocation, 1-year interlock minimum 1 year Yes Mandatory for repeat convictions IID First offenders: 4 months if you agreed to take a breath test; 12 months if you refused a breath test.

Second and subsequent offenders: 14 months from the issuance of limiting driving privileges
Hawaii 5 years None None 1 year After 30 days Mandatory for all convictions IID First offense: 1 year

Second offense: 18 months

Third offense: 2 years
Idaho 10 years 0.2 First offense: Up to $2,000 fine, 10 days to 1 year of jail time, 1-year license suspension (no restricted license available), interlock required after suspension, alcohol evaluation and treatment, Idaho SR-22 additional insurance requirement

Second offense: Felony offense, up to $5,000 fine, minimum 30 days in county jail, up to 5 years in state penitentiary, 1-5 years of license suspension (no restricted license available), interlock required after suspension, alcohol evaluation and treatment, Idaho SR-22 additional insurance requirement

 3-6 months After 30 days Mandatory for all convictions IID 1 year following drivers license suspension
Illinois Lifetime 0.16 First offense: Minimum $500 fine, 100 hours of community service

Second offense: Minimum $1,250 fine, 2 days of mandatory imprisonment

Third offense: Minimum $2,500 fine, 90 days of mandatory imprisonment

Fourth and additional offenses: Minimum $5,000 fine

 1 year After 30 days Mandatory for all convictions; highly incentivized for first convictions Breath alcohol IID Period of statutory license suspension.  5 year interlock requirement for those with 3 convictions.
Indiana Lifetime 0.15 First offense: Up to $5,000 fine, up to 1 year of jail time 30 days – 2 years Available immediately Mandatory for repeat convictions IID or in-car breathalyzer

At least 60 days after your license has been reinstated.
Iowa 12 years 0.15 48 hours of jail time 180 days After 30 days Mandatory for all convictions IID First offense, BAC <0.10: 6 months

Second offense: 1-2 years
Kansas Lifetime 0.15 First offense: 1-year license suspension (as opposed to 30 days)

Second offense: 2-year interlock requirement following suspension

Third offense: 3-year interlock requirement following suspension

Fourth offense: 4-year interlock requirement following suspension

 30 days Can apply for limited license after 45-90 days Highly incentivized for all convictions IID First offense and BAC over 0.08: 6 months if record is clear, 1 year for prior open container violation and/or 3 or more moving violations

BAC over 0.15 the first time or over 0.08 the second or subsequent times, or refusal of a breath, blood, or urine test: Length dependent on priors
Kentucky 5 years 0.15 Increased minimum jail time 6 months Yes Mandatory for all convictions IID First offense: 6 months after license revocation

Second offense within 5 years: 1 year

Third and subsequent offenses within 5 years: 30 months
Louisiana 10 years 0.15 and 0.2 0.15 and above: Enhanced penalties, at court’s discretion

First offense, 0.2 and above: $750-$1,000 fine, 2-year license suspension (as opposed to 1 year)

Second offense, 0.2 and above: 4-year license suspension

 1 year Vehicle confiscation Mandatory for BACs 0.2 and above and repeat convictions; highly incentivized for first convictions IID First offense: For the remainder of your suspension

2 DUI offenses and license revoked for 2 years: 2 years

3 offenses: 3 years

4 or more offenses: 4 years
Maine Lifetime 0.15 Minimum 48-hour imprisonment 150  days Yes Highly incentivized for all convictions IID 2 years as a condition of license reinstatement

2 DUI offenses and license revoked for 2 years: 9 months

3 DUI offenses: 3 years

4 or more offenses: 4 years
Maryland 3 years 0.15 Ineligible for modification of a license suspension or issuance of a restrictive license 90 days Yes, with interlock Mandatory for all convictions IID 1-3 years

BAC of 0.15 or more: 1 year minimum
Massachusetts 10 years 0.2 Mandatory alcohol treatment program 1 year Yes Mandatory for repeat convictions Ignition interlock device (IID) First offense, high BAC: 2 years

Second offense: 2 years

Third offense: 3 years

Fourth and subsequent offenses: 5 years
Michigan Lifetime 0.17 First offense: $200-$700 fine, up to 180 days in jail (as opposed to 90 days), 1-year license suspension (as opposed to 6 months) 30-180 days After 45 days Mandatory for high BAC (0.17) and repeat convictions Breath alcohol IID First offense, BAC <0.17: 6 months

Second offense: 1 year

With a minor: 3 years
Minnesota Lifetime 0.16 Unless maximum bail is imposed, must agree to abstain from alcohol use and submit to daily monitoring of alcohol levels before release from detention 90 days After 15 days Highly incentivized for high BAC (0.16) and repeat convictions IID

or in-car breathalyzer

 First offense BAC >0.16: 90 days

First offense BAC <0.16: 1 year

Second offense: 1 year

Third offense: 3 years
Mississippi 5 years None None 120  days With interlock Mandatory for all convictions IID First offense: 120 days

Second offense: 1 year

Third offense: 3 years after jail time
Missouri 10 years 0.15 and 0.2 0.15 to 0.19: 2-day mandatory imprisonment

0.2 and above: 5 days of mandatory imprisonment

0.15 and above: Mandatory drug or alcohol education/rehabilitation program

 90 days After 0 days with interlock use (restricted)

After 30 days (restricted)

 Mandatory for repeat convictions IID At least 6 months, regardless of prior offenses
Montana Lifetime 0.16 First offense: Up to $1,000 fine, 48 hours to 1 year of imprisonment

Second offense: $2,500 fine, 15 days to 1 year of imprisonment

Third offense: $5,000 fine, 40 days to 1 year of imprisonment

 6 months Yes Mandatory for repeat convictions IID First offense: 6 months

Second offense : 1 year

Third offense: 2 years
Nebraska 12  years 0.15 First offense: Additional $500 fine, 1-year license revocation (as opposed to 2 to 6 months)

Second offense: Additional fine up to $1,000, license revocation up to 15 years

Third offense: Felony charge, additional fine up to $10,000, up to 5 years of imprisonment (as opposed to 1), license revocation of 5-15 years (as opposed to 2-15)

Fourth offense: Class III felony charge, additional fine up to $25,000, up to 20 years of imprisonment, possible use of alcohol-monitoring device for minimum 6 months

Fifth and subsequent offenses: Class II felony charge, additional fine up to $25,000, up to 50 years of imprisonment

 90 days After 30 days Mandatory for all convictions Breath alcohol IID

First offense if you fail chemical test: 180 days

Subsequent offense after 15 years, if you fail chemical

test: 1 year

If you fail a chemical test on arrest: 90 days
Nevada 7 years 0.18 First and second offenses: 12-36 months of mandatory interlock (as opposed to 3-6 months), alcohol treatment 180  days After 45 days Mandatory for all convictions IID or breath interlock device

With <0.18 BAC or higher: 12-36 months

With >0.18 BAC: 185 days
New Hampshire 10 years 0.16 Class A misdemeanor, 5 days to 1 year of jail time, $750-$2,000 fine, interlock required for first offense 9 months No privileges during suspension Mandatory for all convictions IID First offense: 1-2 years if aggravating factors are present (e.g., high BAC)

Second and subsequent offenses: 1-2 years
New Jersey 10 years 0.15 Interlock requirement 3 months Must apply for hardship license Mandatory for all convictions Breath alcohol IID First offense: 6 months to 1 year

Second and subsequent offenses: 1-3 years
New Mexico 55 years 0.16 (with mandatory jail time for all offenses) Aggravated penalty at court’s discretion 1 year Immediately, with ignition interlock Mandatory for all convictions IID First offense: 6 months to 1 year

Second offense: 2 years

Third offense: 3 years

Fourth and subsequent offenses: Lifetime (reviewed after 5 years)
New York 15 years 0.18 First offense: $1,000-$2,500 fine, minimum 1-year license revocation (as opposed to 6 months)

Second and subsequent offenses: Minimum 18-month license revocation

 6 months Yes Mandatory for all convictions IID Minimum of 1 year
North Carolina 7  years 0.15 First offense: 1-year interlock requirement 1 year After 10 days Mandatory for high BAC (0.15 and above) and repeat convictions IID or in-car breathalyzer First offense: 1 year

Second offense: 3 years

Third offense: 7 years (if license is restored)
North Dakota 7 years 0.18 First offense: 180-day license suspension (as opposed to 91 days), minimum $750 fine increase, at least 2 days of imprisonment (court may convert each day into 10 hours of community service)

Second offense: 2-year license suspension

Third offense: 3-year license suspension

 91 days After 30 days Discretionary IID First offense: Not required

Second and subsequent offenses: Encouraged, at court’s discretion
Ohio Lifetime 0.17 Up to $1,075 fine, up to 6 months of jail time, license suspension of 6 months to 3 years 1 year After 15 days Mandatory for repeat convictions IID First offense: 6-18 months

Second offense: 1-4 years

Third offense: 1 year to a lifetime
Oklahoma 10 years 0.15 480 hours of community service, minimum 1 year of supervision and periodic testing

First offense: 18-month interlock requirement

 6 months Yes Mandatory for high BAC (0.15 and above) and repeat convictions; highly incentivized for first convictions IID

First offense: 18 months or until your driving privileges are reinstated

Second offense: 4 years or until your driving privileges

are reinstated

Third and subsequent offenses: Minimum 5 years or until driving privileges are reinstated
Oregon Lifetime 0.15 Minimum $2,000 fine (as opposed to $1,000) 1 year After 30 days Mandatory for all convictions and diversions IID 1 to 5 years
Pennsylvania 10 years 0.1 and 0.16 First offense, 0.1 to 0.15: $500-$5,000 fine, minimum 48 hours of jail time, 12-month license suspension

First offense, 0.16 and above: $1,000-$5,000 fine, minimum 72 hours of jail time, 12-month license suspension

Second offense, 0.1 to 0.15: $750-$5,000 fine, minimum 30 days of jail time, 12-month license suspension

Second offense, 0.16 and above: Minimum $1,500 fine, minimum 90 days of jail time, 18-month license suspension

Third offense, 0.1 to 0.15: $1,500-$10,000 fine, minimum 90 days of jail time, 18-month license suspension

Third offense, 0.16 and above: Minimum $2,500 fine, minimum 1 year of jail time, 18-month license suspension

 No Yes, with programs called Occupational Limited License and Ignition Interlock Limited License Mandatory for BACs over 0.1 and repeat convictions IID First offense: Not required

Second and subsequent offenses: 1 year
Rhode Island 5 years 0.1 and 0.15 First offense, 0.1 to 0.14: $100-$400 fine plus $500 highway assessment fine, 3-12 months of license suspension

First offense, 0.15 and above: $500 fine plus $500 highway assessment fine, 3-18 months of license suspension, minimum 20 hours of public community restitution (as opposed to 10 hours)

Second offense, 0.15 and above: Minimum $1,000 fine plus $500 highway assessment fine, 6 months to 1 year of jail time, 2-year license suspension

Third offense, 0.15 and above: $1,000-$5,000 fine plus $500 highway assessment fine, 3-5 years of jail time, 3-year license suspension

 30 days Conditional hardship license to commute to work, contingent on interlock Mandatory for all convictions IID First offense: 3 months to a year

Second offense: 6 months to 2 years

Third and subsequent offenses: 1 to 4 years
South Carolina 10 years 0.16

First offense: $1,000 fine, 30-90 days of jail time (possibility of community service instead)

Second offense: $3,500-$6,500 fine, 90 days to 3 years of jail time

Third offense, 0.16 and above: $7,500-$10,000 fine, 6 months to 5 years of jail time

Fourth offense, 0.1 to 0.15: 2-6 years of jail time

Fourth offense, 0.16 and above: 3-7 years of jail time

 6 months Yes Mandatory for all convictions IID First offense: 6 months

Second offense: 2 years

Third offense: 3 years

Fourth and subsequent offenses: Lifetime, if license is reinstated (may apply to remove interlock restriction after 10 years)
South Dakota 10 years 0.17 May be sentenced to a 24/7 continuous sobriety monitoring program and must undergo a court-ordered evaluation by a licensed professional 30 days Yes Discretionary IID No mandatory requirements
Tennessee Lifetime 0.2 Minimum 7 days of jail time (as opposed to 48 hours) 1 year Yes Mandatory for repeat convictions; highly incentivized for first convictions IID

or in-car breathalyzer

 Up to 1 year upon license reinstatement, regardless of prior offenses
Texas Lifetime 0.15 1 year interlock requirement 90 days for BAC 0.08 or greater; 180 days for refusal Yes Mandatory for repeat convictions and for BAC 0.15 or higher IID First offense: 90 days to 1 year

Second offense: 180 days to 2 years

Third offense: 1-10 years
Utah 10 years 0.16 1-year interlock requirement (at judge’s discretion for lower BACs) 120 days Temporary limited for employment, education, child visitation Mandatory for repeat convictions; highly incentivized for first convictions IID First offense: Not required, may be a condition of probation

Second and subsequent offenses: Required as a condition of probation for a time period determined by the courts (3 years if under age 21)
Vermont Lifetime 0.16 Prohibited from driving with a BAC of 0.02 or higher for 3 years after conviction (as opposed to 0.08); during these 3 years, driving with a BAC of 0.02 or higher is a DUI and penalized as such 90 days Eligible for interlock-restricted license after 30 days to a year, depending on prior offenses Highly incentivized for all convictions, mandatory for repeat convictions or BAC 0.15 or higher. IID First offense: 6 months

Second offense: 1 year

Third offense: 2  years

Fourth offense: Lifetime license suspension, no interlock possibility
Virginia 11 years 0.15 and 0.2 First offense, 0.15 to 0.2: Additional minimum 5 days of jail time

First offense, 0.2 and above: Additional minimum 10 days of jail time

Second offense, 0.15 to 0.2: Additional minimum 10 days of jail time

Second offense, 0.2 and above: Additional minimum 20 days of jail time, minimum $500 fine

 1 year Yes Mandatory for all convictions IID Minimum 6 months upon license reinstatement, regardless of prior offenses
Washington Lifetime 0.15 First offense: 1-year license revocation

Second offense: 900-day license revocation

Third offense: 4-year license revocation

 90 days With an ignition interlock driver’s license Mandatory for all convictions Breath alcohol IID First offense: Minimum 1 year

Second offense: Minimum 5 years

Third offense: Minimum 10 years
West Virginia 10 years 0.15 Mandatory interlock period 6 months After 30 days Mandatory for BACs over 0.15 and repeat convictions IID First offense: Minimum 6 months

Second and subsequent offenses: Minimum 2 years
Wisconsin 10 years 0.17, 0.2, and

0.25

 0.17 to 0.199: Minimum and maximum fines doubled

0.2 to 0.249: Minimum and maximum fines tripled

0.25 or above: Minimum and maximum fines quadrupled

First offense, 0.15 and above: 1-year minimum interlock requirement

 6 months Yes Mandatory for high BAC (0.15 and higher) and repeat convictions IID First offense: Not required for low-BAC offenders

Second and subsequent offenses: Minimum 1 year, once driving privileges are reinstated
Wyoming 10 years 0.15 Interlock required for 6 months after first offense 90 days Yes Mandatory for high BAC (0.15 and higher) and repeat convictions IID First offense: Not required for low-BAC offenders

Second offense: 1 year

Third offense: 2 years

Fourth and subsequent offenses: Lifetime (can appeal for removal after 5 years)

How Long Do I Need to Use an Interlock?

How long you need to use an interlock depends on the state where you live and whether you have prior DUI convictions. For example, Montana requires individuals to use an interlock for six months after their first DUI conviction, one year after their second, and two years after their third.

In some cases, your BAC at the time of DUI will affect the length of time you need to use an interlock. For example, in North Carolina, after your first DUI conviction, you are required to have an interlock for a year if your BAC was 0.15 or higher.

In addition to using an interlock, you may have to pay other fines and penalties, depending on the state.

Car Breathalyzer vs. Ignition Interlock Device vs. Breath Alcohol Ignition Interlock Device

Car breathalyzer, ignition interlock device (IID), and breath alcohol ignition interlock device (BAIID) are all terms for the same device. The name may vary by state. For example, Illinois and Michigan use the term “breath alcohol ignition interlock device.” Ultimately, they all describe the device used to prevent individuals from driving under the influence.

Can My License Be Restored After a DUI Conviction?

In general, after a DUI conviction, the DMV will restore your driving privileges if you fulfill the conditions that the court ordered. These conditions often include installing an interlock on your vehicle. Some states incentivize the use of interlocks but do not require them.

In addition, before the DMV will restore your driving privileges, you often need to pay a fee. The fee can be expensive and usually increases with each offense. For example, in Illinois, there is a license reinstatement fee of $500.

In states like Arizona and Delaware, you need to complete an alcohol education program. You may need to retake your driver’s license tests, such as the eye screening, written test, and road test.

In some cases, a DUI conviction requires you to serve jail time. For example, in North Carolina, DUI offenders must serve a minimum of 24 hours in jail. Jail time varies depending on state, the circumstances of the DUI, and whether you have prior DUI convictions.

Finally, a DUI conviction and license suspension will affect your car insurance. On average, insurance premiums increase by 80 percent after DUI convictions, and a DUI will likely impact your premiums for at least three years. In some cases, your insurance provider may even drop you as a customer.6

What if Other People Drive My Car That Has an Interlock?

Others are allowed to drive your interlock-equipped car. Before they start the engine, they will need to blow into the mouthpiece, just as you would. There is no way to disable an interlock. Anyone borrowing your car should receive training on how to use the mouthpiece properly and avoid test fails.

Keep in mind that you are responsible for any test fails that show up on your record, so it’s vital that anyone who borrows your car is sober.

In most cases, you must install an interlock on every vehicle you own. If you own multiple vehicles and a family member exclusively drives one of them, you may be able to apply for a waiver. Your state’s DMV will consider waivers on a case-by-case basis and take into account whether installing extra interlocks will cause your family financial hardship.

What Happens if I Buy a New Car or Remove the Interlock?

If you buy a new car, you must install an interlock on the new vehicle. If you don’t, in most cases the DMV will cancel your driver’s license.

Removing or tampering with the interlock will result in fines and an extension of the interlock term. This includes removing the interlock when your term is up. A certified provider should always remove the interlock for you.

IMPORTANT TO KNOW

When your interlock term is up, do not attempt to remove the device yourself. A certified provider should remove it; attempting to remove it yourself will result in fines and an extension of the interlock term.

Can I Rent a Car With an Interlock?

You cannot rent a car if you have an interlock-restricted license. Rental car companies do not have interlock-equipped vehicles and will not rent to individuals with restricted licenses.

Recap

A DUI conviction will often result in a suspended license, which can make it difficult to find auto insurance. Not only will premiums increase, but many auto insurance providers consider individuals with DUIs too risky and refuse to insure them at all. But there are still many insurers who offer affordable DUI insurance.

FAQs

How much does an ignition interlock device cost?

According to interlock provider Intoxalock, ignition interlock devices typically cost $60 to $90 per month, depending on your vehicle type, state, required interlock term, and any additional required features (like a camera or GPS). You may pay a one-time installation fee of $75 to $100. Companies that provide interlocks lease the devices rather than sell them outright.

How long do you have to have an interlock device?

How long you need to have an interlock device on your vehicle depends on your state and whether you have prior DUI convictions. In some states, your BAC at the time of the DUI arrest also impacts the length of your interlock term. Usually, interlock terms start at six months. If you have prior DUI convictions, the state may require you have the device for two years or longer.

The chart below lists the minimum interlock length requirements by state.

State Length of time required to use interlock
Alabama First offense, BAC under 0.15: 6 months

First offense, BAC over 0.15: 2 years

Second offense: 2 year

Third offense: 3 years

Fourth and subsequent offenses: 4 years
Alaska First conviction: 6 months

Second conviction: 12 months

Third conviction: Variable, at the court’s discretion
Arizona Second or third offense, or offense in which you are driving on a suspended or revoked license due to a prior DWI offense, or endanger a child with your drunk driving: 1 year after license suspension/revocation ends or the date of conviction, whichever is later
Arkansas First offense: 6 months

Second offense: 1 year

Third offense: 2.5 years

Fourth offense: Lifetime interlock required
California First offense: 6 months

Second offense: 1 year

Third offense: 2 years
Colorado First offense, BAC >0.15: 8 months

First offense, BAC <0.15: 2 years

Second offense: 2 years
Connecticut First offense: 1 year

Second offense: 3 years
Delaware First offense: 12-23 months

Second offense: 16-28 months

Third offense: 21-33 months

Fourth offense: 54 months
District of Columbia First conviction: 6 months

Second conviction: 1 year

Third and subsequent convictions: 2 years

Third conviction within 5 years: Indefinite
Florida First conviction <0.15 or a minor in the vehicle: 6 months

Second conviction: 1 year

Third conviction: 2 years
Georgia First offenders: 4 months if you agreed to take a breath test; 12 months if you refused a breath test.

Second and subsequent offenders: 14 months from when you are issued limiting driving privileges
Hawaii First offense: 1 year

Second offense: 18 months

Third offense: 2 years
Idaho 1 year following drivers license suspension
Illinois Period of statutory license suspension. 5 year interlock requirement for those with 3 convictions.
Indiana At least 60 days after your license has been reinstated.
Iowa First offense, BAC <0.10: 6 months

Second offense: 1-2 years
Kansas First offense and BAC over 0.08: 6 months if record is clear, or 1 year for prior open container violation and/or 3 or more moving violations

BAC over 0.15 the first time or over 0.08 the second or subsequent times, or refusal of a breath, blood, or urine test: Dependent on priors
Kentucky First offense: 6 months after license revocation

Second offense within 5 years: 1 year

Third and subsequent offenses within 5 years: 30 months
Louisiana Not specified
Maine First offense: For the remainder of your suspension

2 DUI offenses and license revoked for 2 years: 2 years

3 offenses: 3 years

4 or more offenses: 4 years
Maryland 1-3 years

BAC of 0.15 or more: 1 year minimum
Massachusetts First offense, high BAC: 2 years

Second offense: 2 years

Third offense: 3 years

Fourth and subsequent offenses: 5 years
Michigan First offense, BAC <0.17: 6 months

Second offense: 1 year

With a minor: 3 years
Minnesota First offense BAC >0.16: 90 days

First offense BAC <0.16: 1 year

Second offense: 1 year

Third offense: 3 years
Mississippi First offense: 120 days

Second and subsequent offenses: 1 year

Third offense: 3 years after jail time
Missouri At least 6 months, regardless of prior offenses
Montana First offense: 6 months

Second offense: 1 year

Third offense: 2 years
Nebraska First offense if you fail chemical test: 180 days

Subsequent offense after 15 years, if you fail chemical test: 1 year

If you refuse a chemical test on arrest: 90 days
Nevada With <0.18 BAC or higher: 12-36 months

With >0.18 BAC: 185 days
New Hampshire First offense: 1-2 years if aggravating factors are present (e.g., high BAC)

Second and subsequent offense: 1-2 years
New Jersey First offense: 6 months to 1 year

Second and subsequent offenses: 3 years
New Mexico First offense: 6 months to 1 year

Second offense: 2 years

Third offense: 3 years

Fourth and subsequent offenses: Lifetime (reviewed after 5 years)
New York At least 1 year
North Carolina First offense: 1 year

Second offense: 3 years

Third offense: 7 years (if license is restored)
North Dakota First offense: Not required

Second and subsequent offenses: Encouraged, at court’s discretion
Ohio First offense: 6-18 months

Second offense: 1-4 years

Third offense: 1 year to a lifetime
Oklahoma First offense: 18 months or until your driving privileges are reinstated

Second offense: Minimum 4 years or until driving privileges are reinstated

Third and subsequent offenses: Minimum 5 years or until driving privileges are reinstated
Oregon 1 to 5 years
Pennsylvania First offense: Not required

Second and subsequent offenses: 1 year
Rhode Island First offense: 3 months to a year

Second offense: 6 months to 2 years

Third and subsequent offenses:1 to 4 years
South Carolina First offense: 6 months

Second offense: 2 years

Third offense: 3 years

Fourth and subsequent offenses: Lifetime, if license is reinstated (may apply to remove interlock restriction after 10 years)
South Dakota No mandatory requirements
Tennessee Up to 1 year upon license reinstatement, regardless of prior offenses
Texas First offense: 90 days to 1 year

Second offense: 180 days to 2 years

Third offense: 1-10 years
Utah First offense: 18 months

Second offense: 3 years
Vermont First offense: 6 months

Second offense: 1 year

Third offense: 2 years

Fourth offense: Lifetime license suspension, no interlock possibility
Virginia Minimum 6 months upon license reinstatement, regardless of prior offenses
Washington First offense: Minimum 1 year

Second offense: Minimum 5 years

Third offense: Minimum 10 years
West Virginia First offense: Minimum 6 months

Second and subsequent offenses: Minimum 2 years
Wisconsin First offense: Not required for low-BAC offenders

Second and subsequent offenses: Minimum 1 year, once driving privileges are reinstated
Wyoming First offense: Not required for low-BAC offenders

Second offense: 1 year

Third offense: 2 years

Fourth and subsequent offenses: Lifetime (can appeal for removal after 5 years)

Are there different laws around ignition interlocks for high blood alcohol content (BAC) convictions?

Some states apply additional penalties for individuals convicted of driving with a high BAC. For example, some states require an interlock for first-time offenders only if their BACs were over a certain limit. States may apply other penalties, like additional fines, jail time, or license suspension conditions.

The chart below details state laws around increased BAC convictions.

State Limit to be considered increased BAC Increased BAC penalty
Alabama 0.15 6-month additional interlock requirement
Alaska None No increased penalties
Arizona 0.15 and 0.2 0.15 or above: 6-month additional interlock requirement, minimum 9 days of jail time

0.2 or above: Minimum 14 days of jail time
Arkansas None None
California 0.15 “Heightened consideration to applying [an interlock] sanction to a first-offense violator with BAC of 0.15% or more”
Colorado 0.15 Interlock for 1 year
Connecticut None None
Delaware 0.15 and 0.2 0.15 to 0.19: 6-month additional license suspension (18 months total)

0.2 or above: 12-month additional license suspension (24 months total)
District of Columbia 0.2, 0.25, and

0.3

 0.2 to 0.24: Additional 10 days of mandatory jail time

0.25 to 0.29: Additional 15 days of mandatory jail time

0.3 and above: Additional 20 days of mandatory jail time
Florida 0.15 and 0.2 Additional penalties for BAC 0.15 or above while under age 18

First offense: $1,000-$2,000 fine, up to 9 months of jail time, 6-month minimum interlock requirement

Second offense: $2,000-$4,000 fine, up to 12 months of jail time, 2-year minimum interlock requirement

Third and fourth offenses: Minimum $4,000 fine, plus the above penalties
Georgia 0.15 0.15 BAC on first offense receives same sentence as those convicted of second offense: $1,000-$3,000 fine, 6-12 months of jail time (judge may suspend all but 15 days), 5-year license revocation, 1-year minimum interlock requirement.
Hawaii None None
Idaho 0.2 First offense: Up to $2,000 fine, 10 days to 1 year of jail time, 1-year license suspension (no restricted license available), interlock required after suspension, alcohol evaluation and treatment, Idaho SR-22 additional insurance requirement

Second offense: Felony offense, up to $5,000 fine, minimum 30 days in county jail, up to 5 years in state penitentiary, 1-5 years of license suspension (no restricted license available), interlock required after suspension, alcohol evaluation and treatment, Idaho SR-22 additional insurance requirement
Illinois 0.16 First offense: Minimum $500 fine, 100 hours of community service

Second offense: Minimum $1,250 fine, 2 days of mandatory imprisonment

Third offense: Minimum $2,500 fine, 90 days of mandatory imprisonment

Fourth and additional offenses: Minimum $5,000 fine
Indiana 0.15 First offense: Up to $5,000 fine, up to 1 year of jail time
Iowa 0.15 First offense: 48 hours jail time
Kansas 0.15 First offense: 1-year license suspension (as opposed to 30 days)

Second offense: 2-year interlock requirement following suspension

Third offense: 3-years interlock requirement following suspension

Fourth offense: 4-years interlock requirement following suspension
Kentucky 0.15 Increased minimum jail time
Louisiana 0.15 and 0.2 0.15 or above: Enhanced penalties, at court’s discretion

First offense, 0.2 or above: $750-$1,000 fine, 2-year license suspension (as opposed to 1 year)

Second offense, 0.2 or above: 4-year license suspension
Maine 0.15 Minimum 48 hours of imprisonment
Maryland 0.15 Ineligible for modification of a license suspension or issuance of a restrictive license
Massachusetts 0.2 0.2 or above: Mandatory alcohol treatment program
Michigan 0.17 First offense: $200-$700 fine, up to 180 days of jail time (as opposed to 90), 1-year license suspension (as opposed to 6 months), mandatory interlock
Minnesota 0.16 Unless maximum bail is imposed, must agree to abstain from alcohol use and submit to daily monitoring of alcohol levels before release from detention
Mississippi None None
Missouri 0.15 and 0.2 0.15 to 0.19: 2 days of mandatory imprisonment

0.2 or above: 5 days of mandatory imprisonment

0.15 or above: Required drug or alcohol education/rehabilitation program
Montana 0.16 First offense: Up to $1,000 fine, 48 hours to 1 year of imprisonment

Second offense: $2,500 fine, 15 days to 1 year of imprisonment

Third offense: $5,000 fine, 40 days to 1 year of imprisonment
Nebraska 0.15 First offense: Additional $500 fine, 1-year license revocation (as opposed to 2-6 months)

Second offense: Additional fine up to $1,000, license revocation up to 15 years

Third offense: Felony charge, additional fine up to $10,000, up to 5 years of imprisonment (as opposed to 1 year), license revocation of 5-15 years (as opposed to 2-15)

Fourth offense: Class III felony charge, additional fine up to $25,000, up to 20 years of imprisonment, possible use of alcohol-monitoring device for minimum 6 months

Fifth and subsequent offenses: Class II felony charge, additional fine up to $25,000, up to 50 years of imprisonment
Nevada 0.18 First and second offenses: 12-36 months of mandatory interlock (as opposed to 3-6 months), alcohol treatment
New Hampshire 0.16 Class A misdemeanor, 5 days to 1 year of jail time, $750-$2,000 fine, interlock required for first offense
New Jersey 0.15 Mandatory interlock
New Mexico 0.16 (with mandatory jail time for all offenses) Aggravated penalty at court’s discretion
New York 0.18 First offense: $1,000-$2,500 fine, minimum 1-year license revocation (as opposed to 6 months)

Second and subsequent offenses: Minimum 18-month license revocation
North Carolina 0.15 First offense: 1-year interlock requirement
North Dakota 0.18 First offense: 180-day license suspension (as opposed to 91 days), minimum $750 fine increase, at least 2 days of imprisonment (court may convert each day into 10 hours of community service)

Second offense: 2-year license suspension

Third offense: 3-year license suspension
Ohio 0.17 Up to $1,075 fine, up to 6 months in jail, license suspension of 6 months to 3 years
Oklahoma 0.15 480 hours of community service, minimum 1 year of supervision and periodic testing

First offense: 18-month interlock requirement
Oregon 0.15 Minimum $2,000 fine (as opposed to $1,000)
Pennsylvania 0.1 and 0.16 First offense, 0.1 to 0.15: $500-$5,000 fine, minimum 48 hours of jail time, 12-month license suspension

First offense, 0.16 and above: $1,000-$5,000 fine, minimum 72 hours of jail time, 12-month license suspension

Second offense, 0.1 to 0.15: $750-$5,000 fine, minimum 30 days of jail time, 12-month license suspension

Second offense, 0.16 and above: Minimum $1,500 fine, minimum 90 days of jail time, 18-month license suspension

Third offense, 0.1 to 0.15: $1,500-$10,000 fine, minimum 90 days of jail time, 18-month license suspension

Third offense, 0.16 and above: Minimum $2,500 fine, minimum 1 year of jail time, 18-month license suspension
Rhode Island 0.1 and 0.15 First offense, 0.1 to 0.14: $100-$400 fine plus $500 highway assessment fine, 3-12 months of license suspension

First offense, 0.15 and above: $500 fine plus $500 highway assessment fine, 3-18 months of license suspension, minimum 20 hours of public community restitution (as opposed to 10)

Second offense, 0.15 and above: Minimum $1,000 fine plus $500 highway assessment fine, 6 months to 1 year of jail time, 2-year license suspension

Third offense, 0.15 and above: $1,000-$5,000 fine plus $500 highway assessment fine, 3-5 years of jail time, 3-year license suspension
South Carolina 0.16 First offense, 0.16 and above: $1,000 fine, 30-90 days of jail time (possible community service instead)

Second offense, 0.16 and above: $3,500-$6,500 fine, 90 days to 3 years of jail time

Third offense, 0.16 and above: $7,500-$10,000 fine, 6 months to 5 years of jail time

Fourth offense, 0.16 and above: 3-7 years of jail time
South Dakota 0.17 May be sentenced to a 24/7 continuous sobriety monitoring program and must undergo a court-ordered evaluation by a licensed professional
Tennessee 0.2 Minimum 7 days of jail time (as opposed to 48 hours)
Texas 0.15 1 year interlock requirement
Utah 0.16 1-year interlock requirement (at judge’s discretion for lower BACs)
Vermont 0.16 Prohibited from driving with a BAC of 0.02 or higher for 3 years after conviction (as opposed to 0.08), during which driving with a BAC of 0.02 or higher is a DUI and penalized as such
Virginia 0.15 and 0.2 First offense, 0.15 to 0.2: Additional minimum 5 days of jail time

First offense, 0.2 and above: Additional minimum 10 days of jail time

Second offense, 0.15 to 0.2: Additional minimum 10 days of jail time

Second offense, 0.2 and above: Additional minimum 20 days of jail time, minimum $500 fine
Washington 0.15 First offense: 1-year license revocation

Second offense: 900-day license revocation

Third offense: 4-year license revocation
West Virginia 0.15 Mandatory interlock period
Wisconsin 0.17, 0.2, and

0.25

 0.17 to 0.199: Minimum and maximum fines doubled

0.2 to 0.249: Minimum and maximum fines tripled

0.25 or above: Minimum and maximum fines quadrupled

First offense, 0.15 or above: 1-year minimum interlock requirement
Wyoming 0.15 Interlock required for 6 months after first offense

Will I have to use an interlock if this is my first DUI?

Whether you need to use an interlock after your first DUI conviction depends on the state where you live.

In the following 30 states, first time offenders must install an interlock in their vehicle:

  • Alabama
  • Arizona
  • Arkansas
  • Colorado
  • Connecticut
  • Delaware
  • District of Columbia
  • Hawaii
  • Idaho
  • Illinois
  • Iowa
  • Kansas
  • Kenucky
  • Louisiana
  • Maryland
  • Mississippi
  • Nebraska
  • New Hampshire
  • New Jersey
  • New Mexico
  • New York
  • Oklahoma
  • Oregon
  • Tennessee
  • Texas
  • Utah
  • Vermont
  • Virginia
  • Washington
  • West Virginia.

In the following eight states, only high first-time offenders with a high BAC (between 0.1 and 0.17) need to install an interlock:

  • Florida
  • Michigan
  • Minnesota
  • North Carolina
  • Pennsylvania
  • Rhode Island
  • South Carolina
  • Wyoming

The following five states require an interlock for repeat offenders only:

  • Georgia
  • Maine
  • Massachusetts
  • Missouri
  • Ohio

The remaining seven states do not have statewide interlock requirements, but judges can order use at their discretion, including for first time offenders:

  • California
  • Indiana
  • Montana
  • Nevada
  • North Dakota
  • South Dakota
  • Wisconsin
Maya Afilalo Headshot MBA Photo
Written by:Maya Afilalo
Managing Editor & Industry Analyst
Maya Afilalo holds over 10 years of professional experience in writing, communications, and research, which she leverages to provide accurate and reliable information to empower consumers. In addition to overseeing content production, Maya has herself written many articles on auto insurance costs, company comparisons, state laws and requirements, and other topics. She is committed to helping consumers navigate the complex world of car insurance with clarity and confidence. Maya holds a bachelor’s degree from the University of Pennsylvania and a master’s from North Carolina State University.

Citations

  1. Alcohol Ignition Interlocks. NHTSA. (2025).
    https://www.nhtsa.gov/book/countermeasures-that-work/alcohol-impaired-driving/countermeasures/other-strategies-behavior-change/alcohol-ignition

  2. How do I get my license back after a DUI?. madd. (2025).
    https://www.myduiattorney.org/questions/how-do-i-get-my-license-back-after-a-dui

  3. STATE BY STATE LEGAL BLOOD ALCOHOL LIMIT (BAC). Andy Green Attorney at Law. (2025)
    https://www.andygreenlaw.com/dui/state-by-state-bac/

  4. Delaware DUI Laws Overview. DUI Process. (2025).
    https://www.duiprocess.com/delaware-dui-laws-penalties/

  5. State-by-State DUI Penalties. FindLaw.
    https://www.findlaw.com/dui/laws-resources/state-by-state-dui-penalties.html

  6. DOES AN INTERLOCK AFFECT INSURANCE?. Alcolock.
    https://alcolockusa.com/faq/does-an-interlock-affect-insurance/

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