ISS stands for "Ignition Interlock System" — a device that prevents your car from starting if it detects alcohol on your breath
If you see "ISS" printed on your driver's license, it means you are required by law to have an ignition interlock device installed in any vehicle you drive. This is a court-ordered or DMV-ordered requirement, not optional. The device connects to your car's ignition and requires you to blow into a mouthpiece before the engine will start — if it detects alcohol above a set limit (usually 0.02% blood alcohol content), the car will not start.
ISS appears on your license as a restriction or condition. It is one of several codes that can appear on a license to tell police officers, employers, or anyone checking your record that you have specific legal limits on how you can drive. Unlike some restrictions that limit when or where you can drive, ISS is about how you drive — it is a safety measure tied to alcohol-related driving offenses.
Key Takeaways
- ISS on your license means you must have an ignition interlock device installed in your vehicle before you can legally drive.
- The device requires a breath sample before the engine starts and will prevent the car from starting if alcohol is detected.
- ISS is typically ordered after a DUI or DWI conviction, or sometimes after a refusal to take a breath test.
- You will need to pay for the device installation and monthly monitoring fees, which vary by state and provider.
- The restriction stays on your license for a set period determined by the court, usually one to three years depending on your offense and state law.
When ISS appears on your license
ISS is ordered by a court or your state's DMV after a DUI (driving under the influence) or DWI (driving while intoxicated) conviction. In some states, it can also be ordered if you refused to take a breath or blood test during a traffic stop. The specific trigger depends on your state's laws and the details of your case — a first offense in one state might result in ISS, while another state might only require it for repeat offenders.
You will receive notice of the ISS requirement in your court paperwork or in a letter from the DMV. This notice will tell you how long the restriction lasts and whether you must install the device before you can drive again or whether you have a grace period. In most cases, you cannot legally operate a vehicle without the device installed once the order takes effect.
How the ignition interlock device works
The device is a small box, usually about the size of a car radio, that connects to your vehicle's ignition system. Before you can start the engine, you blow into a mouthpiece attached to the device. The device measures your breath alcohol content and either allows the engine to start or locks it out.
If the device detects alcohol above the set limit, the engine will not start. Some devices also require rolling retests — random breath tests while you are driving — to may support you have not consumed alcohol since you started the car. If you fail a rolling retest, the device may log the failure, honk the horn, or flash the lights to alert you and record the violation.
The device records all attempts, passes, and failures. These records are downloaded monthly by the service provider and sent to the court or DMV. If you miss a test, fail too many tests, or tamper with the device, you can face additional penalties, including extended ISS requirements or criminal charges.
Cost and how long you will have ISS
Installation typically costs between $100 and $300, depending on your vehicle and the provider. Monthly monitoring fees range from $50 to $100 or more, and you pay these costs yourself — they are not covered by the court or state. Some providers offer payment plans if the upfront cost is a hardship.
The length of time you must have ISS depends on your state's law and the specifics of your case. Most states require ISS for one to three years. Some states allow you to request early removal if you have a clean record during the monitoring period — meaning you have passed all tests and had no violations. You will need to file a petition with the court and may need to pay a fee to have the device removed.
Driving with ISS on your license
Once ISS is on your license, you can only drive vehicles equipped with an approved ignition interlock device. You cannot borrow someone else's car, rent a vehicle, or drive a company car unless that vehicle has the device installed. If you are caught driving a vehicle without the device, you can face criminal charges, fines, and an extended ISS period.
Some states have exceptions for certain vehicles — for example, commercial vehicles used for work, or vehicles owned by your employer. Check your court order or contact your state's DMV to understand what vehicles you are allowed to drive. If you need to drive a vehicle that does not have a device, you must request a waiver from the court in advance.
Removing ISS from your license
ISS is removed from your license automatically once the court-ordered period ends, provided you have complied with all requirements. You do not need to do anything — the DMV will update your record. However, you must have the physical device removed from your vehicle by an approved installer, and you will need to provide proof of removal to the service provider.
If you want to request early removal, you will need to file a petition with the court that ordered the ISS. You will typically need to show that you have completed at least half the required period, have a clean monitoring record, and have a valid reason for early removal (such as a job change that requires driving a different vehicle). The court will decide whether to grant your request.
Other license codes and restrictions you might see
ISS is one of several codes that can appear on a driver's license. Other common restrictions include corrective lenses required, automatic transmission only, or daylight driving only. Some codes relate to medical conditions, while others relate to traffic violations or criminal convictions. Each code tells law enforcement or employers something specific about how you are allowed to drive.
If you see a code on your license that you do not understand, contact your state's DMV. They can explain what it means, how long it lasts, and what you need to do to comply. Driving in violation of a license restriction is a separate offense and can result in additional fines and penalties.
Frequently Asked Questions
Can I drive someone else's car if they have an ignition interlock device?
No. The device is calibrated to your breath and your driving record. Driving someone else's car with their device installed is illegal and can result in criminal charges. You can only drive vehicles with devices installed specifically for you.
What happens if I fail a breath test while driving?
A failed rolling retest is recorded by the device and reported to the court or DMV at your next monthly read. One failure usually does not result in when ready penalties, but multiple failures can lead to extended ISS requirements, fines, or other court-ordered consequences. The exact penalty depends on your state and court order.
Do I have to tell my employer about ISS on my license?
That depends on your job. If your position requires a valid driver's license or involves driving, your employer may discover the restriction during a background check. Some employers have policies about hiring or retaining employees with DUI convictions or ISS restrictions. Check your employee handbook or ask your HR department.
Can I get my license back without ISS if I move to a different state?
No. ISS restrictions follow you across state lines. If you move, you will need to transfer your license to your new state, and the restriction will transfer with it. Your new state will recognize the court order from your original state and enforce the same requirements.
What if I cannot afford the monthly monitoring fees?
Contact your service provider about payment plans or hardship programs. Some providers offer reduced fees for low-income drivers. You can also request a fee waiver from the court that ordered ISS, though approval is not may provide. Failure to pay fees can result in violations and extended ISS requirements.