Ignition interlock devices — what they cost, and where to install one near you
Court-ordered an interlock after a DUI? Find the certified centers closest to you and what the whole term will actually cost — without talking to a salesperson first.
Estimate your interlock cost
Takes 20 seconds — no account, no phone number
- Installation$65
- Monthly x 12$1,140
- Removal$0
State-capped maximum — a provider may not charge more · law.lis.virginia.gov
Where to install an interlock near you
Interlocks are fitted at certified service centers — usually independent garages and car audio shops approved by a provider. We track 10,531 of them across 51 states. Start with your state.
Cities people search most
States with the most certified centers
Interlock providers, side by side
Providers differ less on the device than on what the full term costs and how far you have to drive for a calibration. Coverage below is counted from our own centers database, not from vendor marketing.
| Provider | Certified centers | |
|---|---|---|
| Intoxalock | 5,927 | Details |
| Smart Start | 2,604 | Details |
| LifeSafer | 2,203 | Details |
| Low Cost Interlock | 1,250 | Details |
| RoadGuard Interlock | 799 | Details |
| ADS Interlock | 502 | Details |
| Guardian Interlock | 207 | Details |
| Alcolock USA | 195 | — |
Prices are published here only once we have verified them with the provider. How we check our data.
What is an ignition interlock device?
An ignition interlock device — often called a car breathalyzer, an IID, or a «blow and go» — is a breath alcohol tester wired into your car’s ignition. Several states call the same thing a BAIID, short for breath alcohol ignition interlock device: Illinois, Tennessee and Missouri all use that acronym in their own paperwork, and it means exactly this device and nothing else. Some state rules call the whole fitted assembly an ignition interlock system, because the handset is only part of it: a control box sits under the dashboard and wires into the starter. Before the engine will start, you breathe into it. If the reading is above the limit your state sets, the car will not start.
It is not a one-off test. While you drive, the device asks for rolling retests at random intervals, and it records every sample, every missed test and every lockout. Those logs go to whoever is monitoring your case — the court, the DMV, or the state agency that issued your restricted license.
In most states the device is installed and serviced by certified centers, and you return every 30 to 60 days for a calibration and data download. More about the devices and how they are fitted.
Breath test to start
A sample above your state’s threshold locks the ignition.
Rolling retests
Random retests while driving, with a window to pull over safely.
Regular calibration
Service visits every 30–60 days, where your data is downloaded.
How an interlock works, day to day
1. Blow before you start
Take a steady breath sample. A clean reading releases the ignition; a failed one starts a short lockout that gets longer if you keep failing.
2. Retest while driving
The device prompts you again at random. You get a few minutes to pull over and blow — a skipped retest is logged as a violation, not as a stall.
3. Service and report
At each calibration visit the center downloads your log and sends it to the agency monitoring your case. Clean months are what shorten your term.
How long will you need the device?
Interlock terms are set by state law and by your offense — a first offense in one state can carry a shorter term than a first offense next door. Pick your state for the rules, the approved providers and the centers we have on file.
Who installs interlocks in the US
Intoxalock
The largest interlock network in the US by service-center count: 5,928 of the 10,618 installation points we index, across 48 states.
Smart Start
Nationwide provider with its own device line and a large installer network.
LifeSafer
One of the oldest interlock brands in the country, run by the same group as Intoxalock and Alcohol Detection Systems.
Low Cost Interlock
Price-led provider that competes primarily on installation and monthly fees.
RoadGuard Interlock
Operates through Nationwide Interlock, which handles its installations and sales; a national network under the RoadGuard brand.
Guardian Interlock
Regional provider with a concentrated service footprint.
Interlock questions people actually ask
How much does an ignition interlock device cost per month?
You pay for an interlock in three parts: a one-time installation fee, a recurring monthly fee that covers the device lease and monitoring, and a removal fee at the end of your term. The monthly fee is the part most people underestimate, because it is charged for every month the device stays in the car.
Monthly pricing is set by the provider and varies by state, so the only honest answer is a state-level one. See our state cost breakdown for the range where you live.
What is the cheapest ignition interlock device?
The cheapest device is rarely the cheapest program. Providers advertise a low installation price and recover it through the monthly lease, calibration visits, and the removal fee — so two providers with the same headline price can differ by hundreds of dollars over a 12-month term.
Compare the full term cost, not the install price: installation + (monthly x months) + removal, plus any state-mandated monitoring fees.
Is there an alternative to an ignition interlock device?
If the interlock is a condition of your restricted or reinstated license, there is normally no substitute — the requirement comes from the court or the state licensing agency, not the provider. Some states allow alternatives such as continuous alcohol monitoring in specific circumstances, and some allow a shorter term for a first offense.
What you can choose is the provider and the service center, which is where the price difference is.
Do police know if you have an interlock device?
Yes. An interlock requirement is normally recorded as a restriction on your driving record and license, so it is visible to an officer who runs your details during a stop.
The device itself also logs every breath sample and reports to the monitoring authority on the schedule your state sets.
Can I drink one beer with an interlock installed?
An interlock will lock you out at a breath alcohol level far below the legal driving limit, and the threshold is set by your state, not by you. One drink shortly before a test is enough to trigger a failed reading on most devices.
A failed test is logged. Depending on your state, a pattern of failed tests can extend your interlock term or trigger a violation review.
What does an ignition interlock device do?
An ignition interlock is a breath-alcohol tester wired into your car ignition. You blow into it before starting the engine; if your breath alcohol is above the state threshold, the engine will not start.
While you are driving, the device asks for rolling retests at random intervals. Every sample, skipped test, and lockout is recorded and sent to the agency monitoring your case.
Where can I find an ignition interlock installer near me?
Devices are installed at certified service centers — usually independent auto shops, car audio installers, or repair garages that have been approved by a provider and, in most states, by the state agency.
Pick your state and city to see the certified centers we have on file, along with which providers each one works with.
The interlock is one part of it
Getting back on the road usually means several things at once: the license itself, SR-22 insurance, court costs, and in some states a class you have to sit before reinstatement. We cover those separately.
Do you need a lawyer?
An honest answer rather than an automatic yes — and the license deadline to protect either way.
What a defense costs
What moves the fee, and what a conviction costs you regardless of who represents you.
Find an attorney near you
DUI cases are heard where the stop happened — local practice matters more than reputation.