A suspended license and interlock device are separate legal consequences, but they often happen together
When your license is suspended, you lose the legal right to drive. An interlock device — also called an ignition interlock or IID — is a breath-testing machine wired into your vehicle's ignition that prevents the engine from starting if it detects alcohol. A court or your state's Department of Motor Vehicles may require an interlock as a condition of getting your license back, or as a condition of restricted driving privileges while your suspension is still active.
The two are not the same thing. You can have a suspended license without an interlock requirement, and you can be ordered to install an interlock without your license being suspended (though this is less common). Most often, they arrive together after a DUI conviction or administrative suspension related to alcohol or drug impairment.
What you do next depends on why your license was suspended, how long the suspension lasts, and whether your state or court has ordered an interlock. The steps are different for each situation, and missing a important date or requirement can extend your suspension or create new legal problems.
Key Takeaways
- A suspended license means you cannot legally drive; an interlock device is a separate requirement that may let you drive under conditions while your suspension is in place.
- You must find out the reason for your suspension and its end date by contacting your state's Department of Motor Vehicles, not by assuming it is related to a recent arrest.
- If an interlock is required, you must install it at a certified vendor, pass a calibration test, and pay installation and monthly monitoring fees that vary by state and vendor.
- Failing an interlock test, missing a required service appointment, or driving without the device can result in license revocation, criminal charges, or both.
- Some states allow restricted driving privileges (work, school, medical appointments) during a suspension if you install an interlock; others do not permit any driving.
Find out the exact reason and length of your suspension
Your first step is to contact your state's Department of Motor Vehicles and ask for the suspension details in writing. Do not assume your suspension is related to a recent DUI arrest — suspensions can result from unpaid tickets, failure to appear in court, unpaid child support, medical conditions, or other reasons entirely. The DMV will tell you the suspension start date, end date, and the reason.
If the suspension is administrative (issued by the DMV without a court order), it usually lasts 90 days to one year depending on your state and whether you refused a breath test. If it is court-ordered (part of a DUI sentence), it can last longer and may have additional conditions attached. Write down the exact end date and keep this document with you.
Some states allow you to request a hearing to challenge the suspension or to ask for a hardship license. The important date to request a hearing is usually 10 to 30 days from the date the suspension was issued. If you miss this important date, you generally cannot challenge the suspension later. Check your state's DMV website or call the suspension unit directly to learn the important date in your case.
Understand what an interlock requirement means and who pays for it
If a court ordered an interlock or your state's DMV imposed one as a condition of license reinstatement, you are legally required to install it before you can drive. The device costs money to install, usually between $100 and $300, and then costs $50 to $100 per month for monitoring and calibration. You pay these fees yourself — there is no government fund or program that covers them.
The interlock must be installed by a certified vendor approved by your state. Your state's DMV website lists approved vendors by county or region. You cannot use an uncertified vendor or install the device yourself. When you call a vendor, ask for the total cost upfront, including installation, the first month's monitoring fee, and any removal fee when you are done.
After installation, the device records every breath test you take and sends the data to the monitoring company. The monitoring company reports the results to the court or DMV. If you fail a test (register above the legal limit), miss a required service appointment, or tamper with the device, the monitoring company reports it, and you can face additional penalties including license revocation or criminal charges.
Install the device and pass the calibration test
Once you have located a certified vendor and paid the installation fee, the technician will wire the interlock into your vehicle's ignition system. The installation takes one to two hours. Before you leave, the technician will give you a calibration test — you blow into the device to establish a baseline. You must pass this test (register below the legal limit) to drive the vehicle home.
If you fail the calibration test, you cannot drive. The vendor will tell you to return after a waiting period (usually 24 hours) and try again. Failing multiple calibration tests may result in the vendor reporting you to the court or DMV, which can trigger additional consequences.
After installation, you will receive a schedule for required service appointments, usually every 30 days. At each appointment, the device is recalibrated and data is downloaded. You must keep these appointments. If you miss one, the monitoring company reports it as a violation. Some states allow a grace period of a few days; others do not.
Know the rules for driving with an interlock device
While your interlock is installed, you must blow into the device before starting your vehicle every time you drive. The device will also require random breath tests while you are driving — usually a beep and a prompt to pull over safely and test within a set time (often five to ten minutes). If you do not test, or if you test positive, the device will log a violation and may disable your vehicle.
You cannot have anyone else blow into the device for you, and you cannot use a device from another vehicle. Both are violations that can result in license revocation. You also cannot disconnect, tamper with, or attempt to bypass the device. If the device malfunctions, you must contact the vendor when ready and report it to the monitoring company.
Some states restrict where and when you can drive while an interlock is installed. You may be limited to driving to work, school, medical appointments, or court-ordered programs only. Other states allow unrestricted driving once the interlock is installed. Check your court order or DMV paperwork to see what restrictions explore to you.
Plan for the cost and timeline to remove the device
The length of time you must keep an interlock installed depends on your state and the reason for the requirement. For a first DUI offense, it is typically six months to one year. For a second or subsequent offense, it can be two to three years or longer. Your court order or DMV paperwork will state the required period.
After the required period ends, you must request removal from the vendor. The vendor will read the final data, verify that you have no violations on record, and remove the device. Removal usually costs $50 to $150. If you have violations on record, the court or DMV may extend the requirement before allowing removal.
Once the device is removed, you still must complete any remaining part of your license suspension. For example, if you were ordered to install an interlock for one year and your license suspension is 18 months total, you will have six months of suspension remaining after the device comes off. During that time, you cannot drive at all.
What happens if you violate interlock requirements or drive without a valid license
Driving with a suspended license is a criminal offense in every state. Penalties include fines (usually $500 to $1,000 or more), jail time (usually a few days to several months), and an additional license suspension. If you are caught driving with a suspended license and an interlock violation on your record, the penalties are more severe.
Interlock violations — failing a test, missing a service appointment, tampering with the device, or having someone else blow into it — are reported by the monitoring company to the court or DMV. The court or DMV can extend your interlock requirement, revoke your license entirely, or file criminal charges depending on your state and the nature of the violation.
If you cannot afford the interlock fees, some states have hardship programs or fee waivers for low-income drivers. Contact your state's DMV or the court that ordered the interlock to ask whether a fee reduction or payment plan is available. Do not skip payments or service appointments because you cannot afford them — report the hardship to the DMV or court instead.
Frequently Asked Questions
Can I drive to work or school while my license is suspended?
It depends on your state and the reason for the suspension. Some states allow a restricted license for essential activities if you install an interlock. Others do not permit any driving during a suspension. Check your court order or contact your state's DMV to learn what is allowed in your case. If restricted driving is available, you must explore for it and meet all conditions, including the interlock requirement.
What if I cannot afford the interlock installation and monthly fees?
Contact your state's DMV or the court that ordered the interlock and ask about hardship waivers, fee reductions, or payment plans. Some states reduce fees for low-income drivers or allow you to pay in installments. If you cannot pay, tell the DMV or court — do not ignore the requirement. Failure to install an interlock when ordered is a violation that can result in license revocation or criminal charges.
What if the interlock device malfunctions or gives a false positive?
Contact the certified vendor when ready and report the malfunction. The vendor will service the device and document the issue. If you have a violation recorded due to a malfunction, ask the vendor to provide written documentation to the monitoring company. You can also request a hearing with the court or DMV to challenge the violation if you have evidence the device was faulty. Keep all service records and receipts.
Can I transfer my interlock device to a different vehicle?
No. The interlock must remain in the vehicle it was installed in. If you need to drive a different vehicle, you must have an interlock installed in that vehicle as well, and you must pay the installation fee again. Some states allow you to have the device transferred to a different vehicle by a certified vendor, but this is not the same as moving it yourself and still requires a technician to reinstall it properly.
What happens after my interlock requirement ends?
You must contact the certified vendor and request removal. The vendor will verify that you have no violations on record and remove the device. If your license suspension is still active after the device is removed, you remain suspended and cannot drive until the suspension ends. Once both the interlock requirement and the suspension end, you can explore to reinstate your license with the DMV.