South Dakota DUI Ignition Interlock: Requirements, Costs, and What to Expect

An ignition interlock device (IID) isn't automatically required for every first-offense DUI in South Dakota. But the court can order one at its discretion, and it's frequently required as a condition of a restricted driving permit or participation in the 24/7 Sobriety Program. Knowing the costs and logistics upfront helps you budget and avoid compliance mistakes that extend the requirement.

When an IID Gets Ordered

For a standard first-offense DUI, an ignition interlock is discretionary — the sentencing judge decides whether to require one. However, certain circumstances make it much more likely:

• BAC of 0.17% or higher (the mandatory 24/7 Sobriety Program threshold)
• Application for a restricted driving permit under SDCL 32-23-2
• Court-ordered sobriety monitoring as a probation condition

If you refused the chemical test and your license was administratively revoked for one year, the Secretary of Public Safety may also require an IID before issuing a restricted administrative permit.

Cost Breakdown

The total cost of an interlock device spans installation, monthly lease, periodic inspections, and eventual removal:

For a six-month interlock period, the estimated total is approximately $800–$900. A twelve-month period pushes past $1,400.

The monthly lease includes a $30 state participation fee. Payments are typically due weekly or monthly to the vendor directly — confirm the schedule at installation.

How It Works Day to Day

The device is wired into your vehicle's ignition system. Before starting the engine, you breathe into a handheld mouthpiece. If the device reads any alcohol above the threshold (typically 0.02% or lower), the vehicle won't start. The device logs every attempt.

While driving, the device requires periodic "rolling retests" — random prompts to blow again while the vehicle is in motion. If you fail a rolling retest, the device logs a violation and may trigger the horn and lights until you pull over and turn off the engine. It does not shut off a moving vehicle.

Sheriff Inspections

The local sheriff's office or police department conducts periodic compliance inspections. These are separate from the vendor's data downloads:

• Initial inspection: $40 (at or shortly after installation)
• Recurring inspections: $20 every 60 days

During an inspection, law enforcement verifies the device is properly installed, reviews the data log for violations or tamper attempts, and confirms the device hasn't been bypassed.

Violations and Extensions

Common violations that get reported to the court:

• Failed breath tests (any positive reading)
• Missed rolling retests
• Tamper alerts (attempting to disconnect or bypass the device)
• Missed calibration appointments with the vendor

Each violation is reported to the sentencing judge and can result in an extension of the interlock period, additional court sanctions, or probation revocation. The interlock vendor transmits data automatically; there's no way to erase a logged event.

Getting the Device Removed

Removal requires a court order or completion of the mandatory period specified in your sentence. The typical process:

1. Confirm with the court or DPS that your interlock period has ended
2. Schedule removal with the approved vendor
3. Pay the removal fee (approximately $40)
4. The vendor provides a compliance report to the court

Intoxalock is currently the primary state-approved interlock provider integrated with South Dakota's 24/7 Sobriety database. Verify current approved vendors with the Attorney General's office, as competitive bidding may introduce additional providers.

The South Dakota First-Offense DUI Guide covers the interlock process alongside the restricted permit application so you can handle both requirements in the right sequence.

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