ISS stands for "Ignition Interlock System," a device that prevents a car from starting if the driver has consumed alcohol
When you see "ISS" printed on your driver's license, it means your state has placed a restriction on your driving privileges. You cannot operate a vehicle without an ignition interlock device installed. The device requires you to blow into a breathalyzer before the engine will turn over. If the device detects alcohol in your breath above a set threshold, the car will not start.
This restriction appears on your license as a condition, not a suspension or revocation. You retain your right to drive, but only in a vehicle equipped with the interlock. The restriction is typically imposed after a DUI or DWI conviction, or sometimes after a refusal to take a breath test during a traffic stop.
Different states use different abbreviations and terminology. Some print "IID" (Ignition Interlock Device) instead of "ISS," and some states call it a "breath alcohol ignition interlock device" or BAIID. The function is the same across all states: prevent drunk driving by making it physically impossible to start the car if alcohol is detected.
Key Takeaways
- ISS on your license means you must have an ignition interlock device installed in any vehicle you drive.
- The device requires a breath sample before the engine will start, and periodic samples while driving.
- This restriction is imposed by court order, usually following a DUI conviction or breath test refusal.
- You can still drive, but only in a vehicle with the device; driving without one while under an ISS restriction is a separate criminal offense.
- The length of the restriction varies by state and by the details of your case, typically ranging from six months to several years.
How the ignition interlock device works
When you get in the car, you blow into the device's mouthpiece. The device measures your blood alcohol content (BAC). If your BAC is below the threshold set by your state—usually 0.02 percent—the device allows the engine to start. If your BAC is at or above that threshold, the engine will not turn over.
Once the car is running, the device requires rolling retests at random intervals. You will hear a prompt, blow into the device again, and the car continues to run if the test passes. If you fail a rolling retest, the device logs the failure and may trigger the horn or lights as a warning, but it does not shut off the engine while you are driving.
The device records every test result and sends the data to a monitoring service. Your probation officer or the court can review this data. Repeated failures, missed tests, or attempts to tamper with the device can result in license suspension or additional penalties.
Who installs and maintains the device
Your state's Department of Motor Vehicles or court will provide you with a list of approved interlock providers. Common national providers include SCRAM Systems, Draeger, and Smart Start, though availability varies by state and region. You must use a provider on your state's approved list.
You are responsible for paying the installation fee, which typically ranges from $100 to $300, and the monthly monitoring fee, which usually runs $60 to $100 per month. Some states offer fee waivers or reductions based on income; ask your provider or the court about this when you are assigned the restriction.
You must visit the provider's office monthly for calibration and data read. The provider sends the data to the monitoring authority. If you miss an appointment, it is treated as a violation and reported to the court.
How long the ISS restriction lasts
The length of time you must use an ignition interlock device depends on your state's law and the specifics of your case. First-time DUI offenders typically face 6 months to 2 years of interlock use. Repeat offenders face longer periods, sometimes 3 to 5 years or more.
Some states allow early removal if you maintain a clean record—no failed tests, no missed appointments, no violations—for a set period, often 6 months. You would petition the court for removal, and the judge decides whether to grant it. Other states require you to complete the full term regardless of your record.
When the restriction period ends, you must return to the provider to have the device removed. The provider notifies the DMV, and your license is updated to remove the ISS restriction. You cannot straightforward disconnect the device yourself.
Driving with an ISS restriction
You can drive any vehicle you own or regularly use, but only if it has an approved interlock device installed. You cannot borrow someone else's car without an interlock, even for a short trip. Driving without the device while under an ISS restriction is a separate offense and can result in criminal charges, license suspension, or jail time.
Some states allow exceptions for certain vehicles—commercial vehicles, motorcycles, or vehicles owned by your employer—but you must request this exception in writing and have it approved by the court or DMV. Do not assume an exception applies to you; check with your probation officer or the court.
If you are caught driving a vehicle without an interlock while under an ISS restriction, you face serious consequences. Many states treat this as a new DUI offense or a probation violation, which can result in extended interlock use, additional fines, or incarceration.
What happens if you fail a test or miss an appointment
A single failed breath test does not automatically end your driving privileges, but it is recorded and reported. Multiple failures within a short period, or a pattern of failures, can trigger a violation report to the court. The court may extend your interlock period, suspend your license, or impose additional penalties.
Missing a monthly appointment is treated as a violation. The provider reports the missed appointment to the monitoring authority. Depending on your state and the number of missed appointments, you may face a license suspension or an extension of your interlock period.
Tampering with the device—disconnecting it, using a tube to bypass it, or attempting to start the car with someone else's breath—is a criminal offense in most states. It results in when ready license suspension and potential jail time.
Removing the ISS restriction from your license
When your interlock period ends, the provider removes the device and notifies the DMV. The DMV updates your license to remove the ISS restriction. This process usually takes one to two weeks. You do not need to visit the DMV in person; the notification happens electronically.
If you want to request early removal before your period ends, you must file a petition with the court that imposed the restriction. You will need to show a clean record—no failed tests, no missed appointments, no violations—for the period required by your state. The judge reviews your petition and decides whether to grant it. Early removal is not may provide and varies by state.
Once the restriction is removed, you can drive any vehicle without an interlock device. Your license will no longer show the ISS notation.
Frequently Asked Questions
Can I drive someone else's car if it has an interlock device?
Yes, if the vehicle has an approved interlock device installed and you are the one blowing into it. You cannot drive a vehicle with an interlock if someone else is the registered owner and the device is set up for their breath sample only. The device must be calibrated to accept your breath sample.
What if I cannot afford the monthly interlock fee?
Many states offer fee reductions or waivers based on income. Contact your interlock provider or ask the court that imposed the restriction about financial hardship options. Some providers offer payment plans. Do not skip payments or appointments; report hardship to the court instead.
Does the ISS restriction show up on a background check?
The ISS notation on your driver's license is visible to law enforcement during a traffic stop. It does not automatically appear on employment background checks, but a DUI conviction does. The interlock restriction itself is tied to your driving record, not your criminal record.
Can I get the restriction removed early if I move to another state?
No. The restriction was imposed by the state where the offense occurred, and you must comply with that state's requirements even if you move. You must petition the original court for early removal. Moving does not suspend or cancel the restriction.
What happens if the interlock device malfunctions?
Contact your provider when ready. A malfunction is not your fault, but you must report it within a set time frame—usually 24 hours—to avoid a violation. The provider will repair or replace the device. Keep documentation of the malfunction and the repair for your records.