ISS stands for "Ignition Interlock System," a device that prevents a car from starting if it detects alcohol on the driver's breath
When ISS appears on your driver's license, it means you are required by law to have an ignition interlock device installed in any vehicle you drive. The device is a breathalyzer connected to your car's ignition system. Before the engine will start, you blow into the device. If it detects alcohol above a set limit — usually 0.02 percent blood alcohol content — the car will not start.
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 as a notation on your license, and law enforcement can see it during a traffic stop. 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 every vehicle you drive, or you cannot legally drive it.
- The device requires you to blow into a breathalyzer before the engine will start, and it tests your breath again randomly while you are driving.
- ISS is ordered by a court as part of a DUI or DWI sentence, and the length of time you must use it varies by state and by the specifics of your case.
- You pay for the device installation and monthly monitoring fees yourself, typically between $60 and $150 per month depending on your location and provider.
- Removing the device early, tampering with it, or driving a vehicle without one installed while ISS is on your license results in criminal charges.
How the ignition interlock device actually works
The device is about the size of a car radio and connects to your vehicle's ignition system. When you get in the car, you blow into a tube attached to the device. The breathalyzer measures your blood alcohol content. If the reading is below the legal limit set by your court order — usually 0.02 percent — the ignition unlocks and you can start the engine.
Once the car is running, the device does not stop there. It requires you to provide breath samples at random intervals while you are driving — typically every 5 to 15 minutes. These are called "rolling retests." If you fail a rolling retest, the device logs the violation and usually triggers an alarm (horn honking, lights flashing) until you turn off the engine. The violation is recorded and reported to the monitoring company and the court.
If you refuse to blow into the device or try to bypass it, that refusal is also recorded as a violation. The device has a camera in some models, which photographs whoever is blowing into it, to prevent someone else from providing a breath sample for you.
How long ISS stays on your license
The length of time you must use an ignition interlock device is set by the court that ordered it. It is not automatic and does not expire on its own. The duration depends on your state's laws, whether this is a first or repeat offense, and the judge's decision in your case.
In many states, a first DUI conviction requires ISS for 6 months to 1 year. A second or subsequent offense typically requires 1 to 3 years. Some states have mandatory minimums. Once the court-ordered period ends, you must petition the court or the DMV to have the ISS notation removed from your license. You cannot straightforward stop using the device.
To remove ISS from your license, you will need to show proof that the device has been uninstalled and that you have complied with all monitoring requirements during the entire period. The monitoring company provides this documentation. You then submit it to the court or DMV — whichever issued the order — and request that the restriction be lifted.
Who installs and monitors the device
You do not choose the device manufacturer, but you do choose the service provider in most states. Common providers include SCRAM Systems, Intoxalock, and Draeger, though availability varies by location. Your court order will specify which providers are approved in your area, or the court will direct you to contact a specific provider.
You contact the provider, schedule an installation appointment, and pay for the installation fee upfront — usually $100 to $300. The provider installs the device in your vehicle, usually at their office or a partner location. The installation takes 30 minutes to 1 hour.
After installation, you pay a monthly monitoring fee, typically $60 to $150 depending on the provider and your state. This fee covers the device, the breath tests, the data transmission to the monitoring company, and the reports sent to the court. You are responsible for all costs. If you miss a payment, the monitoring company reports it to the court, and you can face additional penalties.
What violations mean and what happens next
A violation is recorded any time you fail a breath test, refuse to blow, tamper with the device, or miss a scheduled service appointment. The monitoring company sends a report to the court or the probation officer assigned to your case. The court then decides whether to extend your ISS requirement, impose additional penalties, or revoke your driving privileges entirely.
Common violations include blowing a positive result (alcohol detected), failing a rolling retest, attempting to start the car multiple times in a short period (which suggests trying to bypass the device), or missing a monthly calibration appointment. One violation does not automatically mean your license is suspended, but repeated violations or a single serious violation can result in license revocation.
If you are caught driving a vehicle without an ignition interlock device installed while ISS is on your license, that is a separate criminal charge — usually a misdemeanor, sometimes a felony depending on your state and prior record. This is treated as driving with a suspended license and can result in jail time, fines, and an extension of your ISS requirement.
Removing the device when your requirement ends
When your court-ordered ISS period is complete, you must contact your service provider and schedule a removal appointment. The provider removes the device from your vehicle, usually in 15 to 30 minutes. Some providers charge a removal fee, typically $50 to $100.
After removal, the provider sends proof of uninstallation to the court or DMV. You should also request a letter from the provider confirming that you completed your ISS requirement without major violations. Keep this documentation. You then submit the removal proof to the court or DMV and request that the ISS notation be removed from your license.
The DMV will issue you a new license without the ISS restriction, usually within 1 to 2 weeks. Until you receive the new license, keep the removal letter with you in case you are stopped by law enforcement. Some states allow you to drive without the device once the court-ordered period ends, even if the license notation has not yet been updated, but do not assume this — check with your local DMV or probation officer first.
Driving with ISS: what you need to know
You can drive any vehicle you want while ISS is on your license, but every vehicle you regularly drive must have the device installed. If you own multiple cars, you must install the device in each one, or you can only drive the car that has it. Some people choose to drive only one vehicle to avoid multiple installation fees.
If you borrow someone else's car, that car must also have an ignition interlock device installed, or you cannot legally drive it. This is a common source of violations — people drive a borrowed vehicle without realizing the device is required, fail a breath test, and face court consequences.
You are responsible for keeping the device calibrated and maintained. The monitoring company sends you a notice when your monthly calibration appointment is due. You must go to the provider's office or an approved service location and have the device checked. If you miss this appointment, it is recorded as a violation. Plan ahead for these appointments — they are typically required once a month.
Frequently Asked Questions
Can I get the ISS requirement removed early?
In some states, you can petition the court for early removal after completing half the required time, usually if you have had no violations. This is called a "hardship waiver" or "early termination request." The court has discretion to grant or deny it. You will need to show proof of compliance and may need to appear before a judge. Contact your probation officer or the court that issued the order to learn your state's specific process.
What happens if I blow a positive result on the device?
The device locks and records the violation. You cannot start the car. The monitoring company reports it to the court or your probation officer. Depending on how many violations you have accumulated, the court may extend your ISS requirement, impose additional fines, or revoke your license. A single positive result does not automatically mean your license is suspended, but it is a serious matter.
Do I have to pay for the device myself?
Yes. The court orders you to install and maintain the device, but you pay all costs — installation, monthly monitoring, calibration appointments, and removal. Costs vary by state and provider but typically total $100 to $300 for installation and $60 to $150 per month. Some states have programs that reduce fees for low-income drivers, but you must request this through the court or probation office.
What if I cannot afford the monthly fees?
Contact your probation officer or the court when ready. Missing payments is reported as a violation and can result in license suspension or jail time. Some states have fee reduction programs or payment plans. The court may also allow you to switch to a less expensive provider if one is available in your area. Do not straightforward stop paying — communicate with the court about your situation.
Can someone else blow into the device for me?
Technically yes, but it is a violation of your court order and is illegal. Many newer devices have cameras that photograph whoever is blowing into them, specifically to prevent this. If you are caught, it is treated as tampering with the device, which can result in criminal charges, license revocation, and jail time. The risk far outweighs any benefit.