Driver at a kitchen table comparing an itemized ignition interlock quote with a monthly budget.

How Much Does an Interlock Device Cost Per Month? Installation and Hidden Fees

That ignition interlock quote you got over the phone probably looked simple. One price for installation, a monthly number, done. Then the first bill arrives with charges the phone quote never mentioned.

So how much is an interlock device per month? At Low Cost Interlock, the monthly fee is $78.76. On top of that come one-time charges for enrollment, installation and removal, plus a charge for each calibration visit, and your state’s schedule and fees change the total. Other providers set their own prices, which is why you need an itemized quote to compare two of them.

How Much Is an Interlock Device Per Month?

At Low Cost Interlock (LCI), an interlock device costs $78.76 per month for as long as your requirement lasts. The monthly fee is the lease on the device. Most other charges are either one-time or per visit.

Here’s LCI’s fee list for a standard program:

Enrollment: $40, charged once when you sign up.
Installation: $100 to $250, charged once.
Monthly fee: $78.76, charged each month of your requirement.
Calibration: $20 per visit, on the schedule your state sets.
Removal: $129.50, charged once at the end.

Put together, an average 12-month program at LCI costs $1,200 to $1,500. Your quote confirms the figures for your state and vehicle, and you can request one on the ignition interlock pricing page.

What Goes Into an Interlock Installation

Technician checking a car's wiring in a service bay during an ignition interlock installation.

An ignition interlock device (IID) is a small breath-alcohol unit wired into your vehicle’s ignition system. To drive, you blow into the handheld, the device measures your breath-alcohol content (BrAC), and if you’re under the state-mandated limit, the engine starts.

A complete install covers the handheld unit, the wiring behind the dash, the relay that interrupts the starter circuit, and a first calibration to your state’s limit. The work is done at a state-certified service center. After install, you’ll pay a recurring monthly lease fee, plus calibration visits on the schedule your state requires.

Why Your State Changes the Cost

Your state sets the calibration schedule, the reporting requirements and the lockout rules. Those rules change how many visits and reports you pay for, so two drivers with the same provider can pay different totals because they live in different states.

A quote may not include fees your state charges. Ask specifically: does this quote include any state interlock fee and the first calibration?

Typical Interlock Installation Cost: What to Expect

Interlock installation cost varies based on your state, the device provider, and any add-ons your court order requires. Across the industry, ignition interlock device costs are billed in the same groups: an enrollment or setup charge, an installation charge, the monthly fee, a charge for each calibration visit, and a removal charge. Some states also charge their own program or license fees, which you pay to the state rather than to the provider; your DMV or court paperwork lists them.

Sample Monthly Budgets

Enrollment, installation and removal are charged once, whatever the length of your requirement. The monthly fee and calibration visits repeat, so a requirement longer than 12 months costs more than the average program total above, and a shorter one costs less.

To estimate your own budget, multiply the monthly fee by the months in your order, add a calibration charge for each visit your state requires, and then add the one-time charges.

Hidden Interlock Fees to Ask About Before You Sign

The fees below come up across the industry. Ask each provider which ones apply to you, what each one costs, and whether the answer is in writing. Read every line of any contract before you sign.

Early Termination and Lease-Break Fees

If your lease term runs longer than your requirement, or you sell the vehicle partway through, some providers charge an early termination fee. Always ask: what happens if my IID order is shortened by the court, or if I sell the vehicle mid-lease?

Missed Calibration Penalties

Calibration visits are mandatory. Miss one and your device may enter a lockout state, requiring a service-center visit to reset, often at an extra fee. Some states also report the missed calibration to the DMV as a violation, which can extend your IID period. Book the next visit before you leave the service center so you don’t miss the date.

Lockout Reset Fees

If your device locks out (for example, after a failed test or a missed retest), you’ll typically need to bring it in for a reset. Some providers include lockout resets in the monthly fee and others charge for each one, so ask which applies before you sign. After a lockout, call your provider’s support line before you do anything else; LCI’s is (844) 387-0326.

Failed-Test and Violation Fees

Every test is recorded in the device log, including a failed test or a missed retest, and that log goes to your monitoring authority with the regular report. Some providers charge for the service visit a violation can require, so ask how each one is billed. At LCI, the fee for a tampering or bypass finding is $200.

Equipment Protection Add-Ons

Equipment protection plans cover damage to the device, and they’re usually optional. Ask whether a quoted monthly fee already includes one, and how to cancel it if you don’t want it. At LCI, Equipment Protection is optional, and the charge for device damage is $100 to $1,400, depending on the damage. Read the lease.

“Compliance Reporting” Upcharges

Most state programs require regular reports from the device. Many providers include this reporting at no extra cost. A few list it as a separate monthly charge. If a quote has this as a separate charge, ask why, and compare to a provider that includes reporting in the base monthly rate. LCI includes the required reporting at no additional cost.

Late Payment Fees

Miss a monthly payment and you can expect a late fee; at LCI, it’s $25. Set up autopay if your provider offers it.

What Increases Interlock Cost Beyond the Basics

Three things can raise the cost of an interlock beyond the standard charges: your vehicle, extra requirements in your order, and the number of vehicles you drive.

Vehicle complexity. A push-to-start car, a hybrid, an electric vehicle or a diesel can take more work to wire than a standard sedan, and some need a technician with experience on that vehicle type. Mention your vehicle’s make, model and year when you ask for a quote, because the installation charge can be higher for these.

Extra requirements in your order. If your state or court order calls for more frequent calibration visits or additional reporting, those can add to your monthly cost. They aren’t optional, so compare how each provider prices them.

Multiple vehicles. Requirements vary by state, but in many programs each vehicle you drive needs its own device, which adds a second set of installation and monthly charges. Some drivers find it cheaper to designate a single vehicle for the IID period and use rideshare for everything else.

How to Compare Interlock Quotes

Customer reviewing interlock installation and monthly fees with a staff member at a service counter.

Get at least two written quotes before you book, and make sure each one lists the same charges. A useful comparison covers the install fee, the monthly lease, the calibration cost and interval, the removal fee, any required state fees, and the lease term. If one quote is much lower, check which charges it leaves out.

Ask what “all-inclusive monthly pricing” includes. Reporting fees, lockout resets, missed-calibration penalties, and equipment-protection add-ons should each be addressed in writing.

State interlock requirements differ in who must install a device and for how long, so compare quotes for your own state’s program instead of a national figure.

Payment Questions to Ask

Ask when each charge is billed: whether installation is paid at the appointment, whether the monthly fee is billed each month, and whether any part of the lease is due up front. Paying month to month limits what you’ve paid if your requirement changes. LCI offers flexible billing options.

Keeping Monthly Interlock Costs Under Control After Installation

Driver sorting interlock bills and program paperwork with a calculator to keep monthly costs down.

After installation, the fees you can avoid are the ones tied to violations. Failed tests, missed retests, missed calibrations, and lockouts all generate fees and can extend your IID period. Each of those is preventable, and avoiding an interlock violation mostly means testing with a clear mouth and keeping every appointment. Interlocks also reduce repeat impaired-driving offenses while they’re installed.

A few habits that protect your budget:

Give your mouth time to clear before you test. Mouthwash, breath spray and some foods that can trigger a BrAC reading can cause a false reading, so follow the wait time your provider gives you at installation.
Schedule calibrations early in the appointment window, not at the last possible day. Service-center cancellations happen, and you don’t want a missed appointment to become a lockout.
Keep the device clean and dry. Damage from spills or impact may not be covered without an equipment protection plan.

Removal at the End

When your IID period ends, the device needs to come out. Removal is a one-time appointment, listed with the other one-time charges above, and it should reverse the installation with no permanent change to your vehicle’s wiring. Some states require a final compliance report before the DMV restores your full license, so don’t schedule removal until you’ve confirmed your end date with your state DMV or court. LCI schedules interlock device removal once your requirement ends.

Frequently Asked Questions About Interlock Costs

How much does an interlock cost per day?

Interlock providers bill monthly, so to get a daily cost, divide the monthly fee in the fee list above by the days in the month. Calibration visits and the one-time charges for enrollment, installation and removal add to that, so a full program costs more per day than the monthly fee alone. The quote you request on LCI’s pricing page shows the total for your state.

How much does an interlock device cost to install?

Installation is a one-time charge. At LCI, it’s $100 to $250, depending on your vehicle type, state and location, and there’s a separate $40 enrollment charge. Other providers set their own installation prices, and some states add program fees that you pay to the state. Ask for an itemized written quote so you can see the installation charge on its own.

Which is the cheapest interlock device?

Each provider installs the device approved for your state, so price differences come from how each one charges for enrollment, installation, the monthly fee, calibration and removal. Compare those charges side by side for your state. Low Cost Interlock is one of the most affordable providers and backs quotes with a Price Match Guarantee. Published rates are compared in our list of the cheapest ignition interlock devices.

What if you can’t afford an interlock?

Ask your provider about payment options first; LCI offers flexible billing options. Some states run interlock assistance programs for drivers who qualify based on income, and the court or DMV handling your case can tell you whether yours does and how to apply. Eligibility rules differ from state to state, so confirm them before you book.

Will an interlock device affect my insurance?

Insurance rates usually change because of the impaired-driving conviction behind the requirement, and many insurers raise premiums after one. Some states also require an SR-22 or a similar filing before your license is reinstated, and your insurer submits it for you. Ask your insurer how the conviction affects your policy and whether your state requires a filing.

How many times does interlock go off?

Besides the test to start the car, the device asks for an interlock rolling retest at intervals while you drive. How often depends on your state’s rules and your program, so there’s no single number for every driver. A missed retest is logged and reported, so follow the retest instructions your provider gives you at installation.

Can I drink one beer with interlock?

If there’s alcohol on your breath when you test, the device can record a failed test, and that result goes to your monitoring authority. Some programs also prohibit drinking at all while the device is installed, so check the terms of your order. Skip drinking before you drive, and there’s no alcohol for the device to detect.

Can I buy my own interlock?

In most state programs, no. Interlocks are leased from a state-approved provider, which installs the device at a certified service center, calibrates it and sends the required reports to the state. That’s why the cost is a monthly fee instead of a single purchase price. Your state’s list of approved providers shows who can install one near you.

Build Your Budget Before You Book

Before you book, get an itemized written quote that lists what the monthly fee includes, how often calibration visits are due, and every one-time and add-on charge. Print this breakdown and bring it to your provider conversations. Ask about each charge covered here.

Once your court or DMV requires an interlock, Low Cost Interlock can give you a quote in 60 seconds with no hidden fees, backed by a Price Match Guarantee: we’ll beat any competitor’s quote, or your money back. Call (844) 387-0326 or schedule your installation at an LCI location.

Disclaimer: This article is provided by Low Cost Interlock for general informational purposes only and is not legal, financial, or medical advice. DUI and ignition interlock laws, penalties, fees, and program requirements vary by state, county, and individual circumstances, and they change over time. Any costs, timelines, or figures mentioned are general estimates, not quotes or guarantees. Nothing here should be relied on as a statement of the law in your jurisdiction. Always confirm current requirements with your state DMV, the court handling your case, a licensed attorney, or Low Cost Interlock directly before making decisions. Product features, pricing, availability, and promotions referenced are subject to change and may not be available in every state Low Cost Interlock serves.