ISS stands for "Ignition Interlock System" on your driver's license
An ISS restriction on your driver's license means you are required to use an ignition interlock device in any vehicle you drive. This device prevents a car from starting if it detects alcohol on your breath. The restriction appears as a code or notation on your license itself, and it is a legal requirement — driving without the device installed, or tampering with it, can result in additional penalties.
ISS restrictions are typically ordered by a court as part of a DUI (driving under the influence) or DWI (driving while impaired) sentence. The length of time you must use the device varies by state and by the specifics of your case, but it commonly ranges from several months to a few years. Some states allow you to remove the restriction early if you meet certain conditions, such as completing a substance abuse program or maintaining a clean driving record during the restriction period.
Key Takeaways
- ISS means you must install an ignition interlock device in your vehicle before you can legally drive.
- The device tests your breath for alcohol each time you start the car and periodically while driving.
- Courts order ISS restrictions as part of a DUI or DWI sentence, and the duration depends on your state and case details.
- Removing the device before your restriction ends, or driving a vehicle without one installed, can result in criminal charges and license suspension.
- Some states allow early removal if you complete required programs or maintain a violation-free record during the restriction period.
How the ignition interlock device works
When an ISS restriction is on your license, you must have an approved ignition interlock device installed in your vehicle before you can drive it legally. The device is a small breathalyzer connected to your car's ignition system. To start your vehicle, you blow into the device, and it measures your blood alcohol content (BAC). If your BAC is below the legal threshold set by your state (usually 0.02 percent), the car will start normally.
If the device detects alcohol above the threshold, the engine will not start, and the device records the failed attempt. Most devices also require you to provide breath samples at random intervals while you are driving — this is called a "rolling retest." If you fail a rolling retest, the device typically logs the violation and may trigger a horn or lights to alert you, though it does not force the car to stop when ready.
You are responsible for paying the installation fee and the monthly monitoring cost, which varies by provider and state but typically ranges from $60 to $150 per month. You must also schedule regular maintenance appointments so the device can be serviced and data can be downloaded to your monitoring agency.
How long you must use an ISS device
The length of your ISS restriction is set by the court at sentencing and depends on your state's laws, whether this is a first or repeat offense, and the circumstances of your case. In many states, a first-time DUI conviction results in an ISS requirement lasting 6 months to 1 year. Repeat offenses or cases involving higher BAC levels or accidents often result in longer periods, sometimes 2 to 3 years or more.
Some states allow you to request early removal of the ISS restriction if you meet specific conditions. These might include completing a DUI education or substance abuse treatment program, maintaining a clean driving record with no violations during the restriction period, and paying all fines and fees. You would need to file a petition with the court that ordered the restriction and provide documentation of your compliance.
Other states have mandatory minimum periods during which the device must remain installed, with no option for early removal. Check with your state's Department of Motor Vehicles or your sentencing court to understand whether early removal is possible in your case and what steps you would need to take.
What happens if you violate an ISS restriction
Driving without an ignition interlock device installed when your license has an ISS restriction is a criminal offense in most states. Penalties can include additional fines, jail time, an extended ISS requirement, a longer license suspension, or a permanent license revocation depending on your state and whether you have prior violations. Some states treat a violation as a new DUI offense, which carries even more serious consequences.
Tampering with, disabling, or removing the device yourself is also illegal and is treated as a separate crime. This includes asking someone else to blow into the device so you can start the car — a practice called "circumventing" the interlock. If monitoring data shows that someone other than you provided a breath sample, or that the device was disabled, the violation will be recorded and reported to the court.
If the device records failed breath tests or rolling retests, those violations are logged and sent to your monitoring agency and the court. Depending on how many violations occur, the court may extend your ISS requirement, impose additional penalties, or revoke your driving privileges entirely.
Approved devices and monitoring agencies
Your state's Department of Motor Vehicles maintains a list of approved ignition interlock device manufacturers and service providers. You cannot install just any breathalyzer — it must be a device that meets your state's technical standards and is serviced by an approved monitoring agency. Common manufacturers include ALCO-Safe, Draeger, Guardian Interlock, and SmartStart, though availability varies by state and region.
When you are ordered to install a device, you will be given information about approved providers in your area. You contact one of them to schedule installation, which typically takes 30 minutes to an hour. The provider will explain how to use the device, what your monitoring requirements are, and what happens if you fail a test or miss a service appointment.
The monitoring agency sends reports to the court and your state's DMV on a regular schedule — usually monthly. These reports show whether you have passed or failed breath tests, whether you have maintained the device properly, and whether you have kept your service appointments. The court reviews these reports to determine whether you are complying with your ISS restriction.
Driving privileges with an ISS restriction
Having an ISS restriction does not mean you cannot drive — it means you can only drive vehicles that have an approved ignition interlock device installed. You can drive to work, school, medical appointments, and other necessary places, as long as the device is in the vehicle you are using. Some states allow you to designate certain vehicles as your "restricted driving" vehicles, and only those vehicles need to have the device installed.
If you need to drive a vehicle that does not have the device installed — for example, a rental car or a borrowed vehicle — you must request a waiver or exemption from the court. Waivers are rarely granted and typically only in cases where you can demonstrate a genuine hardship, such as a medical emergency or a job requirement that cannot be met any other way. You would need to file a formal request with the court and provide supporting documentation.
Frequently Asked Questions
Can I remove the ISS device myself before my restriction ends?
No. Removing the device yourself is illegal and is treated as a criminal offense. Only an approved service provider can remove the device, and only after your restriction period has ended or after a court has granted early removal. Tampering with or disabling the device will result in additional criminal charges.
What if I fail a breath test on the ignition interlock?
A failed test is recorded by the device and reported to your monitoring agency and the court. One or two failures may not result in when ready consequences, but repeated failures can lead to an extended ISS requirement, additional fines, or license suspension. The court reviews your monitoring reports regularly to assess compliance.
Do I have to pay for the ignition interlock device?
Yes. You are responsible for paying the installation fee and the monthly service and monitoring costs. These fees are typically your responsibility, though some courts may order the defendant to pay them as part of sentencing. If you cannot afford the device, you may request a fee waiver from the court, though approval is not may provide.
Can someone else drive my car if I have an ISS restriction?
Yes, other people can drive your vehicle as long as the ignition interlock device is installed. However, if the device records a failed breath test or a violation, you are responsible for explaining it to your monitoring agency and the court. If someone else was driving and failed a test, you may need to provide evidence of that to avoid additional penalties.
What is a rolling retest?
A rolling retest is a random breath test that the device requires you to provide while you are already driving. The device will alert you to provide a sample, and you have a set amount of time (usually 5 to 10 minutes) to do so. Failing a rolling retest or not providing a sample within the time limit is recorded as a violation and reported to the court.