Virginia DUI Ignition Interlock: Requirements, Costs, and How It Works

What the Ignition Interlock Device Does

An ignition interlock device (IID) is a breathalyzer wired into your vehicle's ignition system. Before the engine will start, you blow into the device. If your breath registers a blood alcohol concentration at or above 0.02%, the vehicle will not start.

After a first-offense DUI conviction in Virginia, installing an interlock is mandatory for any restricted license. There is no exception, no waiver, and no alternative. Virginia Code § 18.2-270.1 requires it.

The device does more than test you at startup. While driving, it periodically requires a rolling retest — typically within the first few minutes after the engine starts and at random intervals afterward, following a 30-minute rolling-retest protocol. These rolling retests are designed to prevent someone from having a sober person blow into the device at startup and then driving impaired.

Every test result — pass and fail — is logged in the device's internal memory. The data is downloaded at each monthly calibration appointment and transmitted to your VASAP case manager within 24 hours.

How Long You Need the Interlock

The interlock period depends on which restricted license option you chose at sentencing:

• 6-month route-restricted license — Interlock installed for a minimum of 6 consecutive months with zero alcohol violations
• 12-month unrestricted restricted license — Interlock installed for a minimum of 12 consecutive months with zero violations

"Consecutive" is the key word. A single failed test or violation resets the clock. If you blow a 0.02% on month 5 of a 6-month period, you start over.

Costs

The interlock is the most expensive compliance requirement after FR-44 insurance. Here is what the costs look like:

For a 6-month interlock period, total costs run approximately $700 to $900. For 12 months, expect $1,200 to $1,500. These figures do not include the installation complexity surcharge, which applies to certain vehicle types.

Choosing a Vendor

Virginia requires you to use a state-approved interlock vendor. The major providers operating in Virginia include LifeSafer, RoadGuard (formerly Monitech), and Smart Start. Your VASAP case manager will provide the list of approved vendors and issue the electronic authorization for installation.

Vendor selection is your choice, but check a few practical factors:

• Service center locations — You need monthly calibration appointments. Choose a vendor with a service center on or near your regular commute route
• Appointment availability — Some service centers book up quickly. Ask about scheduling flexibility before committing
• Vehicle compatibility — Confirm that the vendor can install on your specific vehicle make and model without the complex-wiring surcharge

The vendor installs the device and transmits proof of installation to VASAP electronically. You do not need to bring paperwork from the vendor to VASAP — the communication is automated.

Monthly Calibration Appointments

Every 30 calendar days, you must bring your vehicle to the vendor's service center for calibration. The technician:

1. Downloads all logged data from the device (startup tests, rolling retests, any failed attempts)
2. Recalibrates the breath sensor for accuracy
3. Uploads the data to VASAP within 24 hours
4. Records the odometer reading
5. Schedules your next appointment

You have a 5-day grace period beyond the 30-day window. Miss the calibration entirely and the device locks out — the vehicle will not start until you complete the service. A lockout is reported to VASAP as a violation.

What Counts as a Violation

The interlock logs several types of events that VASAP treats as violations:

• Failed startup test — BAC at or above 0.02% when trying to start the vehicle
• Failed rolling retest — BAC at or above 0.02% during a retest while driving (the vehicle will not shut off, but the horn may sound and lights may flash; the event is logged)
• Missed rolling retest — Failure to provide a sample within the allotted time window
• Missed calibration — Not completing the monthly service within the 30-day window plus 5-day grace
• Tampering or circumvention attempt — Any evidence of disconnecting, bypassing, or tampering with the device

All violations are transmitted from the vendor to your VASAP case manager, who reports them to the sentencing court. The consequences can include extension of the interlock period, revocation of your restricted license, or additional jail time from the suspended portion of your original sentence.

If You Do Not Own the Vehicle

If the vehicle you drive is owned by someone else — a spouse, parent, or employer — the vehicle owner must sign a notarized "Consent to Install" form authorizing the interlock installation. The device must be installed on every vehicle you operate, not just the one you drive most often.

If you own multiple vehicles, the interlock must be installed on each one. You cannot rotate between an interlock-equipped vehicle and an unequipped one. The monthly calibration and monitoring fees apply per device.

Pre-Trial Installation

You do not have to wait for conviction to install the interlock. Virginia Code § 18.2-271.1 allows pre-trial installation through early VASAP enrollment. Every day the device is installed before trial counts toward the mandatory post-conviction interlock period.

This is a practical advantage if your case will take months to resolve and you need the interlock clock running as early as possible. The risk: if the charge is dismissed or reduced to a non-interlock offense, the fees you have already paid for installation, calibration, and VASAP enrollment are non-refundable.

Where the Interlock Fits in the Full Process

The interlock is one requirement in a chain that includes VASAP enrollment, FR-44 insurance, DMV reinstatement, and court-order embossing. All five must be completed in sequence before you can legally drive on a restricted license.

Our Virginia First-Offense DUI Guide maps the complete sequence from arrest through full license restoration, with every form, deadline, and cost at each stage. If you want to understand how the interlock requirement fits into the larger compliance timeline, the complete guide covers it all.

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