How Long to Keep Your Interlock Device

How long must you keep an ignition interlock device? Most drivers must use it for six months to three years depending on state laws and DUI history. Our guide explains the exact rules for your case and shows how to comply quickly, avoid extra fees, and regain full driving freedom.

When Your Interlock Clock Begins

Many people ask when the time for keeping an ignition interlock device actually starts. The short answer is that in most states, your clock begins on the day the device is installed and reported to the motor vehicle department, not the day you were arrested or convicted.

This matters because you must keep the device for a set period, often six months to a year, with no violations. If you wait months after your sentence to install it, those months usually do not count toward your required time. That can make the whole process longer and more costly.

The day you get the interlock installed and certified is the day your required time starts ticking.

Let’s look at a few examples so you can see how it works in real life. John in Arizona got a DUI in January but installed his device in March. His six-month clock started in March, not January. Sara in Texas had her device installed the same week as her conviction, so her time matched the court order closely.

What Triggers the Start Date

Your start date depends on your state rules and the paperwork from your installer. Most shops send a notice to the DMV within a few days. Until that notice is logged, the clock has not begun. Always keep your installation receipt and confirmation letter.

Here are the usual steps that begin your interlock clock:

1. Receive court or DMV order to install the device.
2. Visit a certified installer and have the IID placed in your car.
3. Installer sends proof to the state agency.
4. State logs the date and your required period begins.

Some states use a table like the one below to show common start points:

Make sure to call your local DMV if you are unsure. A quick check can save you from extra months with the device. Keeping a simple calendar note helps you track the day your time will end.

First-Time DUI Interlock Length: How Long You Must Keep the Device

If you get a DUI for the first time, you may need to install an ignition interlock device (IID) in your car. The length of time you must keep it depends on your state and your case. Most first-time drivers have to use the device for about six months to one year.

Some states set a fixed time, while others let a judge decide. For example, in California a first DUI often means 6 months with an IID. In Texas, it can be 12 months if your blood alcohol was high. Always check your local DMV rules to know your exact time.

Most first-time DUI drivers should plan for at least half a year with the interlock.

What Changes the Interlock Time?

Your interlock length can change for a few simple reasons. A higher blood alcohol level or refusing a breath test can add months. Some states also give shorter times if you finish a drinking course.

• Blood alcohol over 0.15%: often adds 6 more months.
• Refusing test: may double the time.
• Good behavior: sometimes early removal.

Here is a quick look at a few states for first DUI:

Keep your device working and send reports on time. If you miss a calibration, the clock may restart. Talk to your probation officer to avoid surprises.

Repeat Offense Extended Terms

If you get a DUI more than once, the time you must keep an ignition interlock device gets much longer. Most states add extra months or years to the requirement because they want to keep repeat drinkers off the road.

For a second offense, you may need the device for one to three years. A third offense can mean five years or more. The exact time depends on your state and the judge’s order. Always check your local law to know your exact term.

Ignition interlock devices for repeat offenses often stay on cars for double the time of a first conviction.

State Examples for Repeat Offenses

Look at these examples to see how different places handle repeat offenses. The table below shows common rules for second and third DUIs.

These numbers are a basic guide. Some judges can make the time longer if your blood alcohol was very high or if someone got hurt.

To stay safe, plan to keep the device until your paper says it is done. Remove it early and you may face new fines or jail.

• Keep all calibration receipts.
• Drive only the car with the device.
• Ask your probation officer before any changes.

If you follow the rules, the extended term will pass and you can get the interlock removed. Then you can drive like normal again.

Early Removal Eligibility Rules

Many drivers ask if they can take the ignition interlock device off sooner than the court ordered. The short answer is maybe. Each state has its own early removal eligibility rules, and they often depend on your driving record while the device is installed.

For example, if you blow into the device and pass every time, you may qualify for early removal after a set period. Some states ask for six months of clean tests, while others require a full year. Always check with your local DMV or court to see the exact rule for you.

State Examples and Waiting Times

Look at the table below to see a few common state rules. These show how early removal eligibility rules change by location. Times are minimums with no violations.

Rules can change, so treat this as a starting point. A clean record is the best way to get early relief.

Most states require at least six months of violation-free use before you can apply for early removal.

How to Ask for Early Removal

When you think you meet the early removal eligibility rules, follow these steps. They help you show proof and avoid delays.

1. Get a report from the interlock company showing your test logs.
2. Fill out the state form for early termination.
3. Pay any fee and send the papers to the court or DMV.

If approved, you can schedule a service visit to take the device out. Keep copies of all papers in case questions come up later.

Violations That Lengthen Interlock Use

Getting an ignition interlock device (IID) means you must blow into it to start your car. Most states set a base time, like 6 months or 1 year. But if you break the rules, you can keep the device much longer.

Common mistakes include failing the breath test, trying to start the car with someone else’s breath, or missing a service appointment. Each slip adds weeks or months to your required time. The exact penalty depends on your state and your court order.

A single missed calibration can add 30 days to your interlock order.

Common Violations and Extra Time

Below are typical slip-ups that make your interlock period longer. Always check your local rules because numbers vary.

• Failed breath test: Any reading over the limit often adds 30 to 90 days.
• Skipped monthly service: Missing a calibration visit can extend the order by one month.
• Tampering or bypass: Using a friend to blow counts as fraud and may add 6 months or more.
• Power cycle trick: Unplugging the device to avoid a retest can reset your clock.

If you get a new DUI while the interlock is installed, the court will likely start a fresh long term. That means you could be stuck with the device for years instead of months.

Stay on track by marking service dates on your calendar and never letting another person blow into the unit. A clean record is the fastest way to get the IID removed.

Final Device Calibration and Removal Steps

Before the court-ordered interlock period expires, you must complete a final calibration to confirm the device has maintained accurate readings and stored compliance data. A certified technician will connect the unit to diagnostic software, verify zero violations, and print a report that serves as proof of successful use.

Once the final calibration is approved and the required lock-in time has fully elapsed, the provider will schedule physical removal of the ignition interlock. The technician disconnects the device, restores the vehicle’s starting circuit, and issues a removal certificate that you should submit to the DMV or monitoring authority.

Reference Sources

1. Intoxalock
2. Smart Start
3. LifeSafer