How Long Do You Need an Ignition Interlock in Utah?

Utah sets ignition interlock restriction periods by statute, under Utah Code Section 41-6a-518.2, and the length depends on the offense. A standard first-offense DUI carries an 18-month restriction. Repeat offenses, refusals, felony DUI, and automobile homicide carry longer periods, up to four years. These are mandatory minimums, so the court cannot cut them below the statutory floor, but violations can push them past it.

The period does not run from your conviction date. It begins when the device is installed and you reinstate as an interlock restricted driver, which means prompt installation starts the clock sooner and satisfies the requirement sooner, while a delay in installation pushes your end date back. This page covers each restriction period, what extends it, how it ends, and what the full term costs. Glen Neeley has advised clients on interlock timing since 1998, and the mechanics of the requirement itself are covered on our page about Utah's ignition interlock requirements.

Interlock Restriction Periods by Offense

Utah's interlock restrictions fall into four lengths. The offense that produced the restriction determines which one applies to you.

18 months for a first-offense DUI

An 18-month restriction applies to a first-offense DUI conviction, and it applies regardless of the breath or blood result. That catches people off guard, because a first offense with a result of .16 or higher is an extreme DUI under Utah Code Section 41-6a-501(1)(f). That definition is broader than the .16 figure alone: it also reaches a result of .05 or higher combined with any measurable controlled substance, and the presence of two or more controlled substances that were not prescribed. Extreme DUI raises the jail exposure to not less than five days, or two days in jail plus 30 days of home confinement, under Section 41-6a-505(1)(a)(i). What extreme DUI does not do is lengthen the device requirement. The interlock restriction stays at 18 months.

The same holds for a first offense with a passenger under 16, which Utah charges as a class A misdemeanor. The higher classification changes the penalty range the court is working with, but it does not by itself push the interlock past 18 months.

Two years for a repeat offense, an under-21 driver, or a refusal

A two-year restriction applies in three situations: a second or repeat DUI committed within 10 years of a qualifying prior conviction, a DUI by a driver who was under 21 at the time, and an administrative revocation for refusing a chemical test. That 10-year window is measured from the prior conviction, not from arrest date to arrest date, and a qualifying prior is broader than a prior DUI conviction, which is why the Utah DUI look-back period is worth understanding before you assume a case is a first offense.

Refusal cases carry a wrinkle worth knowing before you act. A driver who elects early reinstatement in order to drive sooner commits to an interlock restriction whose length is unsettled (the Driver License Division and the statute differ between two and three years), so confirm the period with the Driver License Division. That tradeoff deserves a deliberate decision rather than a quick one, and it is one of the points covered in whether an interlock can come off early.

Three years for felony DUI

A three-year restriction applies to felony DUI. Under Utah Code Section 41-6a-502(2)(c), a DUI is a third-degree felony when the driver has two or more qualifying prior convictions each within 10 years, and also when the current conviction comes at any time after a prior felony DUI conviction. That second path has no 10-year window on it at all. Three years is the period the public often assumes covers any aggravated case, but under current law it belongs to felony-level offenses.

Four years for automobile homicide

A four-year restriction applies to a conviction for automobile homicide under Utah Code Section 76-5-207. It is the longest interlock period in the Utah DUI framework.

What Can Extend the Interlock Period Beyond the Minimum

Each period above is a floor, not a ceiling. Several things add time to it.

Interlock violations

Failed breath tests, missed rolling retests, missed monitoring appointments, and evidence of tampering each trigger an extension. Under Utah Code 53-3-1007(8)(a) the Driver License Division must add 60 days for each failed start attempt with a measurable amount of alcohol and for each missed monitoring appointment, and the extensions stack. The Driver License Division reviews the data your device reports and can add time to the requirement. Knowing what counts as an interlock violation before one happens is worth the few minutes it takes, and the consequences a violation carries reach past a longer end date.

Failure to install the device

The clock does not start until the device is installed. If the court orders installation and the driver delays, the restriction stays in place, the completion date moves back, and further consequences can follow. Driving a vehicle without the required device while you are interlock restricted is a class B misdemeanor, and it results in a new two-year interlock restriction.

Probation violations

When interlock compliance is a condition of probation, a violation can lead the court to extend the requirement as part of revised probation conditions.

Completing the requirement on schedule comes down to four habits: install promptly, comply strictly, attend every monitoring appointment, and avoid alcohol entirely for the duration. Monthly monitoring costs multiply with each month of extension, so compliance protects your calendar and your budget at the same time.

When the Interlock Period Ends

The restriction ends when the mandatory minimum has been served without violations and the Driver License Division authorizes removal. At that point you contact your interlock provider to schedule a removal appointment. The removal fee is typically $50 to $100, and it varies by provider.

Removal does not close out the case. Any remaining probation conditions continue, and finishing the interlock does not automatically satisfy other DUI-related obligations. One point worth clearing up: a DUI by itself does not create an SR-22 insurance requirement in Utah. That comes from a separate financial responsibility violation, most commonly a no-insurance conviction, and where it applies it runs on its own schedule regardless of the interlock.

Why the removal date matters for expungement

For expungement purposes, the sentence is not complete until the interlock requirement and every other component is satisfied. The waiting period for a DUI runs from the conviction or from release from incarceration, parole, or probation, whichever came last, and all fines, interest, and restitution have to be paid in full first. If interlock removal is the last component you finish, its date can be what starts the 10-year expungement waiting period that Utah applies to a DUI conviction.

Felony DUI sits outside that framework entirely. It is categorically ineligible for expungement under Utah Code Section 77-40a-303(2)(a)(iv), and the only routes back to eligibility are a reduction to a misdemeanor under Section 76-3-402 or a pardon, which is covered on our page about expunging a felony DUI.

What the Full Restriction Costs

Interlock monitoring commonly runs $70 to $150 per month, with an installation fee at the start and a removal fee of roughly $50 to $100 at the end. Exact figures vary by provider. Because the total scales with the length of the restriction, an 18-month first-offense period commonly totals in the range of $1,400 to $3,000, while the two-year, three-year, and four-year periods for repeat, felony, and automobile homicide cases cost proportionally more.

Two things push the total higher than the base estimate. If you operate more than one vehicle, each vehicle needs its own device. And every violation that extends the period adds months of monitoring to the bill. A fuller breakdown is on our page about what an ignition interlock costs in Utah.

What Happens at a Calibration Appointment

Calibration appointments are required at regular intervals, typically every 30 to 60 days depending on the service provider and the court order. During calibration the technician downloads the data log from your device, recalibrates the sensor accuracy, and inspects the unit for tampering or damage. The appointment usually takes 30 to 60 minutes.

The data download is one of the most important parts of the visit. The device records every breath sample, every failed test, every missed rolling retest, and any attempt to tamper with the unit. That data is reported to the Utah Driver License Division and, in some cases, to your probation officer or the court. If the data shows violations, consequences can follow quickly. Our office reviews data reports with clients to identify potential issues before they escalate.

How Device Data Downloads Affect Your Case

Every ignition interlock device maintains a continuous data log. The log captures timestamps for each breath test, the reading for each sample, vehicle start and stop times, any skipped or missed rolling retests, and power disconnection events. That data is downloaded at each calibration appointment and transmitted to the monitoring authorities.

Data patterns matter. A single marginally elevated reading may be explainable, but a pattern of borderline readings, missed retests, or power interruptions creates a record that the Driver License Division or the court may read as noncompliance. As a board-certified DUI defense attorney and NCDD faculty member, Glen Neeley knows how to read and challenge interlock data when the results do not accurately reflect a client's behavior.

Daily Life With an Ignition Interlock in Utah

Living with an ignition interlock device changes your morning routine. Before starting the vehicle you provide a breath sample into the handset. The device takes a few seconds to analyze it. If the reading is below the preset threshold, the vehicle starts normally. If it is above the limit, the device locks the ignition for a timed waiting period before you can retest.

Cold weather in Utah adds a wrinkle. During winter the device may take longer to warm up and give accurate readings. We advise clients to allow extra time before scheduled departures, particularly from December through February when temperatures in the Salt Lake Valley and surrounding areas regularly drop below freezing. Store the handset where it will not freeze overnight.

Passengers may ask about the device. There is no legal prohibition against having passengers while driving with an interlock, and you are not required to explain the device to anyone. Keep in mind that the unit prompts rolling retests while you drive, so you will need to provide additional breath samples with the vehicle in motion. Those retests are timed, and missing one can trigger a violation.

Common Interlock Myths Versus Reality

Several misconceptions follow these devices around. One is that mouthwash or certain foods will cause a failed test. Some products containing alcohol can produce a brief elevated reading, but the device is calibrated to detect ethanol at specific concentrations, and rinsing with water and waiting a few minutes before testing typically clears residual mouth alcohol from food or hygiene products.

Another myth is that someone else can blow into the device for you. Modern units use camera verification and breath-pattern recognition to prevent circumvention. Having another person provide a sample is a violation that carries serious consequences, including an extended interlock period and potential criminal charges.

Some drivers believe that disconnecting the battery will reset the device or erase violation data. It will not. Power disconnections are logged and reported, and tampering with the device or its power source creates additional violations that can extend the restriction period and bring further penalties from the Utah Driver License Division.

Questions About Interlock Duration in Utah

Talk to Glen Neeley About Your Case

Which interlock period you serve is decided by how the underlying case resolves, and that is where a defense attorney can still change the outcome. If you are facing a DUI, a refusal revocation, or an interlock violation that could extend your restriction, call 801-645-5008 for a free, confidential consultation. Glen W. Neeley handles each DUI case personally and is available 24/7 to clients statewide.