What ISS Means on Your Florida Driver's License

ISS is a code that appears in the "Restrictions" section of your Florida driver's license and means "Ignition Interlock System Required."

When you see ISS printed on your license, it tells law enforcement and you that you are required to drive only vehicles equipped with an ignition interlock device — a machine that tests your breath for alcohol before the engine will start. This restriction is imposed by Florida courts as a condition of driving privileges after a DUI (driving under the influence) conviction or arrest.

The ISS code does not mean your license is suspended or invalid. It means your driving is permitted, but only under this specific condition. Driving a vehicle without an interlock device when ISS appears on your license is a violation and can result in additional criminal charges, license suspension, or both.

Key Takeaways

ISS on your Florida license means you must use an ignition interlock device in any vehicle you drive.
The court orders ISS as part of a DUI sentence, and the requirement appears in your license restrictions section.
You can drive vehicles equipped with an interlock device; you cannot legally drive vehicles without one.
The length of the ISS requirement depends on your DUI conviction history and the court's order, typically ranging from six months to several years.

When ISS Appears on Your License

ISS is added to your Florida driver's license by court order following a DUI conviction or, in some cases, after a DUI arrest when the court imposes it as a condition of pretrial release. The Florida Department of Highway Safety and Motor Vehicles (DHSMV) does not decide whether to impose ISS — the court does. Once the court issues the order, DHSMV prints the restriction code on your next license or on a replacement license if you request one when ready.

You do not need to do anything to have ISS added to your license. The court notifies DHSMV of the restriction, and it appears automatically when your license is printed or renewed. However, you are responsible for understanding what it means and complying with it from the moment the court order takes effect.

How the Ignition Interlock Device Works

An ignition interlock device is a breath-testing machine wired into your vehicle's ignition system. Before you can start the engine, you must blow into the device. If it detects no alcohol or alcohol below the legal threshold (typically 0.02 percent), the engine starts normally. If it detects alcohol above that level, the engine will not start.

The device also requires rolling retests — random breath tests while you are driving — to may support you have not consumed alcohol during your trip. If you fail a rolling retest, the device logs the violation and may honk the horn or flash the lights to alert you. You must still drive safely to a safe location and stop; the device does not disable the engine while you are moving.

The interlock device records all tests, passes, and failures. These records are downloaded periodically and reviewed by the court or your probation officer to monitor compliance. Tampering with the device, failing tests, or missing a service appointment can result in license suspension or additional penalties.

How Long ISS Stays on Your License

The length of time you must maintain an ignition interlock device depends on the court's order and your DUI history. For a first DUI conviction in Florida, the court typically orders ISS for a minimum of six months. For a second or subsequent DUI within ten years, the requirement is usually longer — often one to three years or more.

The court order specifies the exact end date of the ISS requirement. You cannot remove the device or stop using it before that date, even if you have had no violations. Once the court's important date passes, you can have the device removed and request a new license without the ISS restriction. DHSMV will issue a replacement license showing that the restriction has been lifted.

Installing and Maintaining an Interlock Device

You are responsible for finding and paying for the installation and maintenance of your ignition interlock device. Florida does not provide the device or cover its cost. You must choose a service provider that is certified by the Florida Department of Highway Safety and Motor Vehicles. A list of certified providers is available on the DHSMV website.

Typical costs range from $100 to $300 for installation and $50 to $100 per month for monitoring and maintenance, though prices vary by provider and location. You must have the device serviced regularly — usually every 30 days — so the service provider can read the test records and may support the device is functioning correctly. Missing a service appointment is a violation and can trigger license suspension.

You must also pay for the removal of the device once your ISS requirement ends. Some providers include removal in their service fee; others charge separately. Confirm the removal cost and process with your provider before you sign an agreement.

Driving with ISS: What You Can and Cannot Do

With ISS on your license, you can drive any vehicle that has an ignition interlock device installed and functioning. You cannot legally drive any vehicle without one, even for a short trip, even if someone else is driving and you are a passenger, and even in an emergency. Driving a vehicle without an interlock when ISS is on your license is a separate criminal offense.

Some courts allow limited exceptions — for example, driving a vehicle owned by your employer that is not equipped with an interlock, or driving a rental car for work — but only if you obtain written permission from the court before you drive. Do not assume an exception applies to you. If you need to drive a vehicle without an interlock, contact the court or your probation officer in writing and request permission in advance.

You are also required to notify your insurance company that you have an ignition interlock device. Some insurers charge higher premiums for drivers with ISS; others do not. Failing to disclose the device to your insurer can void your coverage in the event of an accident.

Removing ISS from Your License

Once the court's ISS requirement period ends, you must take two steps to remove the restriction from your license. First, have the ignition interlock device physically removed by a certified service provider. The provider will give you a removal certificate or letter confirming the date of removal.

Second, visit a Florida DHSMV office in person and request a replacement license. Bring your current license and the removal certificate from the service provider. You will pay the standard replacement license fee (currently $25 for a Class D license). DHSMV will issue a new license without the ISS restriction, usually on the same day.

Do not wait to request the replacement license. Driving with an expired ISS requirement on your license can create confusion with law enforcement and may complicate your record. Request the new license as soon as the device is removed.

Frequently Asked Questions

Can I drive someone else's car if it has an interlock device?

Yes, if the device is installed and functioning. The device is tied to the vehicle, not to you personally. You can drive any vehicle equipped with a working interlock device. You cannot drive any vehicle without one, regardless of who owns it.

What happens if I fail a breath test while driving?

The device logs the failure and may alert you with a horn or light, but it does not stop the engine while you are moving. You must drive safely to a safe location and stop. The failure is recorded and reported to the court or probation officer. Repeated failures can result in license suspension or additional criminal charges.

Can I get the ISS requirement removed early?

Only the court that imposed the requirement can modify or remove it early. You can petition the court for early removal, but approval is not may provide. You will need to show evidence of compliance, such as a clean interlock record with no violations or failed tests, and demonstrate that early removal is in the interest of justice.

What if I cannot afford the interlock device?

Cost is not a legal reason to avoid installing the device. However, some service providers offer payment plans. You can also contact the court or your probation officer to ask whether financial hardship programs or reduced-cost providers are available in your area. Failure to install the device is a violation of your court order.

Does ISS affect my ability to renew my license?

You can renew your license while ISS is on it. The restriction will appear on your renewed license. You do not need to do anything special to renew; follow the normal Florida license renewal process. The ISS requirement continues until the court's important date, regardless of when you renew.

This guide is for general information only and is not medical, financial, legal, or other professional advice. For decisions specific to your situation, consult a qualified professional. See our Editorial Policy.