ISS stands for "Ignition Interlock System" and it's a device that prevents your car from starting if it detects alcohol on your breath
If your driver's license has an ISS restriction printed on it, you are required by law to have an ignition interlock device installed in your vehicle before you can drive. This restriction appears on your license after a DUI or DWI conviction in most states. The device itself is a small breathalyzer that connects to your car's ignition — you blow into it before the engine will start, and it measures your blood alcohol content.
The ISS restriction is not optional. Driving without the device installed when your license requires it is a separate criminal offense and can result in additional fines, jail time, or license suspension. You cannot remove the restriction yourself; only the court or your state's DMV can do that, and only after you have completed the required period of use.
Key Takeaways
- An ISS restriction on your license means you must have an ignition interlock device installed in every vehicle you drive.
- The device requires you to pass a breath test before your car will start, and random retests while driving to prevent circumventing the system.
- ISS restrictions are ordered by a court as part of a DUI or DWI sentence and typically last between six months and three years depending on your state and offense history.
- You pay for the device installation and monthly monitoring fees yourself, which usually range from $60 to $150 per month.
- Tampering with, removing, or attempting to bypass the device is a felony in most states and will result in when ready license suspension and criminal charges.
How the ignition interlock device actually works
When you get in your car, you cannot start the engine until you blow into the device's mouthpiece. The device analyzes your breath and sends the result to a monitoring company. If your blood alcohol content is below the legal threshold (usually 0.02 percent, which is lower than the 0.08 percent DUI limit), the car starts normally.
The device does not stop there. While you are driving, it will prompt you to provide random breath samples at intervals — typically every 30 to 60 minutes. You have a set amount of time (usually 5 to 10 minutes) to pull over safely and provide the sample. If you fail any of these rolling retests or do not provide a sample in time, the device logs a violation and may trigger your car's lights and horn as a warning.
Every test you take — whether you pass or fail — is recorded and reported to the monitoring company. Your probation officer or the court can review this data at any time. The device also records if someone tampers with it, if the battery dies, or if you try to disconnect it.
When ISS appears on your license and how long it lasts
An ISS restriction is ordered by a judge as part of your DUI or DWI sentence. It does not appear automatically — the court must specifically order it as a condition of your probation or sentence. In some states, ISS is mandatory for all DUI convictions; in others, the judge has discretion to order it based on factors like your blood alcohol level at the time of arrest, whether you caused an accident, or whether you have prior DUI convictions.
The length of time you must use the device varies significantly by state and by your specific case. A first-time DUI offender might be required to use ISS for six months to one year. A second or third offense, or a case involving a high blood alcohol level or an accident, can result in two to three years of ISS requirements. Some states allow the court to order ISS for longer periods in serious cases.
You cannot straightforward stop using the device when you think the time is up. You must receive written confirmation from the court or DMV that your ISS requirement has ended. The monitoring company will not remove the device without this official order.
Who installs and monitors the device
You do not choose your own device or monitoring company — the court typically assigns an approved provider in your state. Common national providers include SCRAM, Draeger, and Intoxalock, but your state may have a different list of authorized vendors. You will receive paperwork from the court telling you which provider to contact and where to go for installation.
Installation usually takes 30 minutes to an hour and happens at a service center. The technician will explain how to use the device, show you how to blow into it correctly, and give you a schedule for your first few weeks of testing. You will also receive a phone number to call if the device malfunctions or if you have questions.
The monitoring company checks in with you regularly — typically monthly — to read data from the device and review your test results. You may do this in person at their office or, in some cases, remotely. If your data shows violations or failed tests, the monitoring company reports this to the court or your probation officer, which can result in additional penalties.
What you pay for ISS and how to budget for it
The cost of an ignition interlock device is your responsibility, not the court's or the state's. Installation fees typically range from $100 to $300 depending on your vehicle and the provider. Monthly monitoring and lease fees usually run between $60 and $150 per month, again depending on your state and the specific provider.
Some states cap the maximum monthly fee; others do not. A few states offer reduced fees for low-income individuals, but you will need to request this and provide proof of income. Contact your assigned provider directly to ask about their fee structure and whether any discounts are available to you.
Over the course of a typical one-year ISS requirement, you could spend $800 to $2,000 total. If your requirement lasts two or three years, that cost doubles or triples. This is separate from any fines, court costs, or increased insurance premiums that come with a DUI conviction.
What happens if you violate ISS requirements
A violation does not necessarily mean you failed a breath test. Violations include failing a test, refusing to take a test, not showing up for a monitoring appointment, tampering with the device, driving a vehicle without the device installed, or attempting to bypass the system in any way. Even a single violation can have serious consequences.
When a violation is reported to the court, the judge may extend your ISS requirement by several months, increase your fines, add jail time to your sentence, or suspend your license entirely. Tampering with or removing the device is treated as a separate felony offense in most states and can result in criminal charges on top of your original DUI sentence.
If you are caught driving a vehicle that does not have the required device, you face charges for driving with a suspended or restricted license, which carries its own penalties including fines and possible jail time. The best approach is to treat the ISS requirement seriously and use the device every time you drive.
How to get the ISS restriction removed from your license
You cannot remove an ISS restriction yourself, and the monitoring company cannot remove it for you. Only the court that ordered it or your state's DMV can officially terminate the requirement. The process varies by state, but generally works like this: once you have completed the required period of ISS use without violations, you or your attorney file a motion with the court asking for the restriction to be lifted.
The court will review your monitoring data to confirm you have complied with all requirements. If everything is in order, the judge signs an order removing the ISS requirement. You then take this order to your state's DMV, which issues you a new driver's license without the ISS restriction. The entire process can take several weeks to a few months.
If you have violations on your record, the court may deny your request to remove the restriction and extend your ISS requirement instead. This is why compliance throughout the entire period is critical — one violation late in your requirement can add months or years to how long you must use the device.
Frequently Asked Questions
Can I drive someone else's car if it doesn't have an ignition interlock device?
No. If your license has an ISS restriction, you are not permitted to drive any vehicle that does not have an approved device installed, regardless of who owns it. Driving someone else's car without the device is a violation and can result in additional criminal charges for driving with a suspended or restricted license.
What if the ignition interlock device breaks or malfunctions?
Contact your monitoring company when ready and report the malfunction. They will schedule a repair or replacement appointment, usually within a few days. Keep documentation of the malfunction and the repair date. As long as you report it promptly and get it fixed, a mechanical failure is generally not counted as a violation. However, if you delay reporting it or continue driving without getting it repaired, that is a violation.
Do I have to install the device in a vehicle I own, or can I use a rental car?
You can install the device in any vehicle you regularly drive — whether you own it, lease it, or borrow it. Some people use rental cars for occasional trips, but most rental companies do not allow ignition interlock devices to be installed in their vehicles. Your best option is to have the device installed in a vehicle you own or have regular access to. Check with your monitoring company about their policy on multiple vehicles.
Will the ISS restriction show up on background checks for employment?
The ISS restriction itself will not appear on most employment background checks, but the underlying DUI conviction will. Employers who conduct background checks will see your criminal record, which includes the DUI. Some employers may ask about the conviction during the hiring process. The ISS restriction is a court-ordered condition of your sentence, not a separate criminal charge, so it typically does not appear on background checks on its own.
Can I get the ISS requirement reduced or removed early?
In some states, you can petition the court for early removal of the ISS requirement if you have maintained a perfect compliance record for a certain period — often at least half of the original requirement. This is not may provide, and the judge has discretion to deny your request. You would need to work with an attorney to file this motion and present evidence of your compliance to the court.