ISS stands for "Ignition Interlock System" and it means your license has a restriction requiring you to use a special device before your car will start
An ISS restriction on your driver's license indicates that you are required by law to install an ignition interlock device in any vehicle you drive. This device measures your breath alcohol content before the engine will turn over. If the device detects alcohol above a set limit — usually 0.02% blood alcohol content — the car will not start.
ISS restrictions are typically ordered by a court as a condition of driving after a DUI (driving under the influence) or DWI (driving while impaired) conviction. The restriction remains in place for a set period, which varies by state and the specifics of your case. During this time, you cannot legally drive any vehicle without the interlock device installed, even if you own multiple cars.
Key Takeaways
- ISS means you must install an ignition interlock device in your vehicle before you can drive legally.
- The device tests your breath alcohol before allowing the engine to start, and you pay a monthly fee to maintain it.
- ISS restrictions are court-ordered and last for a specific period set by the judge, usually ranging from several months to several years.
- You must use the device in every vehicle you drive, and tampering with or circumventing it can result in criminal charges and extended restrictions.
How the ignition interlock device actually works
When you get in your car, you blow into the handheld device mounted on your dashboard. The device analyzes your breath sample and sends the result to a monitoring company. If your blood alcohol content is below the legal limit set for your restriction, the device allows the engine to start normally.
The device also requires rolling retests while you drive — random breath tests that happen at intervals (usually every 5 to 15 minutes after you start the car). You have a set amount of time to provide the sample, usually a few minutes. If you fail a rolling retest or do not provide a sample, the device logs the violation and may trigger the horn and lights as a warning, though it will not shut off the engine while you are moving.
Every month, you must visit a service center to have the device downloaded and inspected. The monitoring company reviews all your breath tests and rolling retests from that month. The service center also checks that the device has not been tampered with or disconnected.
What the restriction costs and how long it lasts
Installation of an ignition interlock device typically costs between $100 and $300, depending on your state and the service provider. Monthly monitoring and maintenance fees range from $50 to $100 per month. You are responsible for paying these costs yourself — they are not covered by insurance or any government program.
The length of your ISS restriction depends on your state's laws and the judge's order. First-time DUI offenders often have restrictions lasting 6 months to 1 year. Repeat offenders or cases involving high blood alcohol content may face restrictions of 2 to 5 years or longer. Some states allow you to request early removal if you maintain a clean record during the restriction period, but this requires a separate court petition and is not automatic.
What happens if you violate the ISS restriction
Driving without the device installed when your license has an ISS restriction is a criminal offense in every state. Penalties include additional fines, jail time, license suspension, and an extended interlock requirement. A violation can also result in the restriction being extended by months or years.
Tampering with the device — disconnecting it, having someone else blow into it, or attempting to bypass it — is also a crime. These actions are recorded by the monitoring system and reported to the court. Consequences include criminal charges separate from your original DUI case, extended interlock requirements, and possible jail time.
If you fail multiple breath tests or rolling retests during your restriction period, the monitoring company reports this to the court. Repeated failures can result in license suspension, extension of the restriction, or other penalties depending on your state's laws.
Removing the ISS restriction from your license
To have the ISS restriction removed, you must complete the full term ordered by the court while maintaining a clean record — meaning no failed breath tests, no tampering violations, and no missed service appointments. Once you have completed the required period, you can petition the court or your state's Department of Motor Vehicles to have the restriction lifted.
The process for removal varies by state. Some states automatically remove the restriction once the term expires if your record is clean. Others require you to file a formal petition with the court and may require a hearing. You may also need to provide proof from the monitoring company that you completed the program successfully.
If you have failed tests or violations on your record, you will likely not be able to have the restriction removed early. The court may require you to extend the program or complete additional requirements before removal is considered.
Driving with an ISS restriction: what you need to know
You can drive any vehicle you want during your restriction period, but every vehicle must have the device installed. If you own multiple cars, you will need to install the device in each one, or you can have it transferred between vehicles at a service center — though this typically costs an additional fee.
The device works in all weather conditions and all climates. Cold weather does not prevent it from functioning, though extremely cold temperatures may occasionally cause calibration issues that require a service visit. The device is designed to be discreet and does not advertise your restriction to passengers.
You should plan extra time before driving to provide your breath sample. The process usually takes less than a minute, but if you have eaten, used mouthwash, or consumed certain foods, you may need to wait a few minutes before retesting. The device will not start if it detects mouth alcohol from these sources.
Frequently Asked Questions
Can someone else blow into the device to start my car?
No. The device is calibrated to your breath and is designed to detect attempts to use someone else's breath. Using another person's breath is considered tampering and is a criminal offense. The device logs all attempts, and violations are reported to the monitoring company and the court.
What if I need to drive for work or medical reasons during my restriction?
You can still drive for any reason — work, medical appointments, groceries, or anything else — as long as the device is installed in your vehicle. The ISS restriction does not limit where you can drive or why you can drive. It only requires that the device be present and functioning in any car you operate.
Does the device record who is driving the car?
No. The device records breath test results and whether the car started, but it does not identify who provided the breath sample. However, you are legally responsible for all tests performed in your vehicle, and allowing someone else to drive your car with the device installed is your responsibility.
What if I move to a different state while my ISS restriction is active?
Your restriction follows you. You must maintain the device in your vehicle and continue service appointments in your new state. Contact your new state's Department of Motor Vehicles and the monitoring company to transfer your account. Failure to maintain the device in your new state is a violation of your original court order.
Can I have the device removed early if I have a clean record?
Some states allow early removal through a court petition if you have maintained a perfect record during your restriction period. However, this is not automatic and is not available in all states. You would need to file a formal request with the court that issued your original order and may need to attend a hearing. Check with your state's Department of Motor Vehicles or your attorney for the specific process in your area.