ISS stands for "Ignition Interlock System" — a device that prevents your car from starting if it detects alcohol on your breath
When ISS appears on your driver's license, it means you are required by law to have an ignition interlock device installed in your vehicle before you can drive. The device is a breathalyzer connected to your car's ignition system. You blow into it before the engine will start, and if it detects alcohol above a set limit (usually 0.02% blood alcohol content), the car will not turn on.
ISS requirements are imposed by courts as a condition of driving after a DUI or DWI conviction, or sometimes after a refusal to take a breath test. The restriction appears on your license as a reminder to you and as notice to law enforcement that you must have the device installed. Driving without the device installed when ISS is on your license is a separate criminal offense.
Key Takeaways
- ISS on your license means you must have an ignition interlock device installed in any vehicle you drive.
- The device measures your breath alcohol level before allowing the engine to start, typically set to block the car if you have consumed any alcohol.
- ISS is ordered by a court as part of a DUI or DWI sentence, not something you can remove on your own.
- You are responsible for paying the installation and monthly monitoring fees, which typically range from $60 to $150 per month depending on your state and provider.
- The restriction stays on your license for a set period determined by the court, usually one to three years depending on your conviction and state law.
How the ignition interlock device actually works
The device is a small handheld unit wired into your vehicle's ignition system. When you get in the car, you blow into the mouthpiece for several seconds. The device analyzes your breath and sends a pass or fail signal to the ignition. If your breath alcohol is below the set limit, the car starts normally. If it is above the limit, the ignition locks and the car will not start.
Most devices also require rolling retests — random breath tests while you are driving — to may support you have not consumed alcohol since you started the car. If you fail a rolling retest, the device logs the violation and may trigger the horn and lights to alert you to pull over safely. These violations are reported to the monitoring company and can be reviewed by the court.
The device records every test result, every attempt to start the car, and every violation. This data is downloaded monthly by the monitoring company and sent to the court or probation officer overseeing your case. A pattern of failed tests or tampering attempts can result in license suspension or additional penalties.
Why ISS appears on your license after a DUI or DWI
Courts use ISS as a safety measure and a condition of keeping your driving privileges after an alcohol-related conviction. Instead of suspending your license entirely, many jurisdictions allow you to drive — but only with the interlock device installed. This lets you maintain employment and handle necessary travel while preventing you from driving under the influence.
The requirement is mandatory in most states for first-time DUI convictions, and is almost always required for repeat offenses or convictions involving high blood alcohol levels. Some states also impose ISS after a breath test refusal, treating the refusal as evidence of impairment even without a confirmed BAC reading.
How long ISS stays on your license
The duration depends on your state law and the specifics of your conviction. For a first DUI offense, ISS typically remains on your license for one to two years. For repeat offenses or high BAC readings, the period can extend to three years or longer. Some states impose a mandatory minimum period before you can even request removal.
You cannot remove ISS from your license yourself. Once the court-ordered period ends, you must petition the court or DMV to have the restriction lifted. Your monitoring company will provide documentation showing you completed the requirement without violations. You may need to file paperwork with your local court or submit the completion certificate to your state's DMV, depending on your state's process.
The cost of maintaining an ignition interlock device
You are responsible for all costs associated with the device. Installation typically costs $100 to $300 as a one-time fee. Monthly monitoring and maintenance fees range from $60 to $150, depending on your state and the monitoring company assigned to you. Some providers charge additional fees for failed tests, rolling retests, or service calls.
A few states offer cost reduction programs for low-income drivers, but these are limited and require separate process. Most people pay the full amount out of pocket. Over a two-year ISS period, the total cost can reach $1,500 to $3,600 or more. This is in addition to fines, court costs, and increased insurance premiums that typically follow a DUI conviction.
What happens if you drive without the device when ISS is on your license
Driving a vehicle without an ignition interlock device installed when ISS is on your license is a separate criminal violation. Penalties vary by state but typically include additional fines, license suspension, and possible jail time. Law enforcement can check your license status during a traffic stop and will know when ready that you are required to have the device.
If you are caught driving without it, the court may extend your ISS requirement, impose a longer license suspension, or add criminal charges on top of your original DUI conviction. You should not attempt to drive any vehicle — including a rental car, a friend's car, or a work vehicle — without the device installed.
Removing ISS from your license after the requirement ends
When your court-ordered ISS period is complete, the device must be physically removed from your vehicle by a certified technician. Your monitoring company will provide instructions for scheduling the removal appointment. You will receive a removal certificate documenting that the device has been uninstalled and that you completed the program.
To have ISS removed from your driver's license itself, you must submit the removal certificate to your state's DMV or to the court that ordered the restriction, depending on your state's procedure. Some states remove it automatically once the monitoring company reports completion; others require you to file paperwork. Contact your local DMV to confirm what documentation they need and where to submit it.
Frequently Asked Questions
Can I get ISS removed from my license early?
Some states allow early removal if you demonstrate a clean record with no failed tests or violations during the monitoring period. You would need to petition the court that ordered the restriction. Early removal is not automatic and depends on your state's law and the judge's discretion. Contact the court or your probation officer to learn whether early removal is an option in your case.
What if I fail a breath test on the interlock device?
A single failed test is recorded but typically does not when ready end your driving privileges. However, repeated failures or a pattern of violations can trigger a license suspension or additional court penalties. The monitoring company reports all results to the court monthly, so the judge can see your compliance record.
Do I have to install the device in every car I own?
Yes. ISS requires the device in any vehicle you operate. If you own multiple cars, each one must have a device installed. If you drive a company vehicle or rental car, that vehicle must also have the device. You cannot legally drive any vehicle without it while ISS is on your license.
Can I travel out of state with an ignition interlock device?
You can travel, but the device must remain installed and functional in your vehicle. Some states have reciprocal agreements recognizing ISS requirements from other states; others do not. Before traveling, contact your monitoring company and the DMV in the state you are visiting to confirm whether your device will be recognized and whether you need additional documentation.
What if the interlock device malfunctions?
Contact your monitoring company when ready. They will schedule a service appointment to repair or replace the device. A malfunction does not excuse you from the ISS requirement, and you should not drive the vehicle if the device is not working properly. Keep records of all service calls in case the court questions your compliance.