ISS stands for "Ignition Interlock System" on your driver's license
When you see "ISS" printed on your driver's license, it means you are required to use an ignition interlock device in any vehicle you drive. An ignition interlock is a breathalyzer machine installed in your car that measures your blood alcohol content before the engine will start. If the device detects alcohol above a set limit — usually 0.02% — the car will not start.
This restriction appears on your license as a condition, not a punishment you can ignore. It is a legal requirement tied to a DUI or DWI conviction, or sometimes to a refusal to take a breath test during a traffic stop. The presence of ISS on your license tells police officers, rental car companies, and anyone else checking your driving record that you must comply with this requirement.
Key Takeaways
- ISS means you must install and use an ignition interlock device in any vehicle you operate.
- The device prevents your car from starting if it detects alcohol in your breath above the legal threshold.
- ISS appears on your license as a mandatory condition, usually following a DUI conviction or breath test refusal.
- Driving without the device installed, or tampering with it, is a separate criminal offense in most states.
- The length of time you must use the device varies by state and the specifics of your case, typically ranging from several months to years.
How the ignition interlock device actually works
When you get into your vehicle, you blow into the device's mouthpiece before you can start the engine. The machine analyzes your breath and sends a result to a central monitoring company. If your blood alcohol content is below the threshold, the car starts normally. If it is above the limit, the engine will not turn over, and the device records the failed attempt.
The device also requires rolling retests while you are driving — typically every 5 to 15 minutes after you start the car. This prevents someone from blowing into the device sober and then drinking while driving. If you fail a rolling retest, the device logs it and may trigger your car's lights and horn as a warning, though it will not shut off the engine while you are moving.
You must visit a service provider monthly to have the device checked and data downloaded. The monitoring company sends reports to the court or your state's licensing authority showing whether you have complied with the requirement. These reports are part of your case file and can affect whether your license restriction is lifted early.
Why ISS appears on your license after a DUI or DWI
States use ignition interlock requirements as a way to prevent repeat drunk driving. The logic is straightforward: if you cannot start your car without proving you are sober, you cannot drive drunk. Many states now require ignition interlock for all DUI convictions, not just repeat offenders, though some reserve it for higher blood alcohol levels or for drivers who refused a breath test.
The specific trigger varies by state. Some states mandate ISS for any DUI conviction. Others require it only if your blood alcohol content was above a certain level — often 0.15% or higher. A few states impose it automatically if you refused to take a breath or blood test during the traffic stop. Your state's DUI laws and the facts of your case determine whether ISS will be part of your sentence.
How long you will need to use the device
The duration of an ignition interlock requirement is set by the court at sentencing and varies widely. A first-time DUI conviction might require the device for 6 months to 1 year. A second or third conviction typically extends the requirement to 1 to 3 years. Some states allow you to petition the court for early removal after you have shown a clean compliance record, usually after half the original term has passed.
Your state's licensing authority tracks your compliance through the monthly reports from the monitoring company. If you have no failed tests, no missed appointments, and no attempts to tamper with the device, you may be may be able to access to request removal before the full term ends. However, if you fail a test or miss a service appointment, the clock often resets, and you may have to start the requirement over from the beginning.
What happens if you drive without the device installed
Driving a vehicle without an ignition interlock when ISS is on your license is a separate criminal offense in every state. It is not straightforward a violation or a fine — it is typically charged as a misdemeanor and can result in jail time, additional fines, license suspension, and an extension of your interlock requirement. A second offense for driving without the device can be charged as a felony in some states.
Police can discover the violation through a traffic stop, a check of your driving record, or a report from the monitoring company if your vehicle is registered in your name but has no active interlock device. Even if you are not caught when ready, the violation creates a new criminal case that compounds the consequences of your original DUI conviction.
Costs and practical considerations of ISS
Installation of an ignition interlock device typically costs between $100 and $300, depending on your state and the provider. Monthly monitoring and maintenance fees usually range from $50 to $100 per month. You are responsible for paying these costs, and they continue for the entire duration of your requirement. Some states offer payment plans or reduced fees for low-income drivers, but you must request this through the court or licensing authority.
The device is not invisible — it is a visible box with a tube attached to your steering column. If you drive a vehicle you share with others, they will see it and know about your restriction. Some people choose to use ride-sharing services or rely on others for transportation during the interlock period rather than deal with the visibility and cost, though this is a personal choice based on your circumstances.
How to get ISS removed from your license
Once your interlock requirement period ends, you do not automatically have the restriction removed from your license. You must contact your state's Department of Motor Vehicles or licensing authority and request removal. You will need to provide proof that you have completed the full term or that the court has granted early removal. This usually means submitting a letter from the monitoring company confirming your compliance, along with a court order if early removal was granted.
After you submit the paperwork, the licensing authority will issue you a new license without the ISS restriction. This process typically takes 1 to 4 weeks, depending on your state's processing time. Until you receive the new license, you are still legally required to use the device if you drive.
Frequently Asked Questions
Can I drive someone else's car if I have ISS on my license?
No. The restriction applies to you as a driver, not to a specific vehicle. Any car you operate must have an ignition interlock device installed. If you drive a vehicle without one, you are breaking the law, even if the car belongs to someone else.
What if I fail a breath test on the interlock device?
A failed test is recorded by the monitoring company and reported to the court or licensing authority. One or two failures may not result in when ready consequences, but repeated failures can lead to license suspension, extension of your interlock requirement, or additional criminal charges. The specific consequences depend on your state's laws and the terms of your sentence.
Can I get the device removed early?
Many states allow early removal if you have maintained a clean compliance record for a set period — often half the original requirement. You must petition the court with proof of compliance from the monitoring company. Early removal is not automatic and is granted at the judge's discretion.
What if I cannot afford the monthly fees?
Contact your state's Department of Motor Vehicles or the court that sentenced you to ask about reduced-fee programs or payment plans. Some states offer information for low-income drivers. You can also ask the monitoring company directly whether they offer hardship programs.
Does ISS stay on my record after the device is removed?
The ISS restriction is removed from your license once you complete the requirement, but your DUI conviction remains on your driving record permanently. The conviction itself affects insurance rates and background checks for employment or housing, even after the interlock device is no longer required.