Ignition interlock device: who installs in your state
Wired into the ignition, a small breath tester called an ignition interlock device lets your car start only if your breath is clean. Find out who does the install in your state and schedule the visit.
You'll then see the installers in your state and what happens with a first DUI.
Choose your state from the list, or tap it on the map.
What an ignition interlock device does
An ignition interlock device is just a breath tester about the size of a cell phone. Once it's wired into your car, you blow into it to start the engine. According to Mothers Against Drunk Driving (MADD), the device won't let the car start if there's alcohol on your breath.
While you drive, the device will ask for another breath a few times, at moments you can't predict. Rolling retests is the name for these extra breaths you give while driving. Their job is to confirm the driver is the same person who took the first breath test.
The cost to you
- Installation
- $70 to $150
- Monthly
- $60 to $80
You don't buy the device; you rent it from an interlock company. Installation usually runs from $70 to $150, according to MADD. After that, expect to pay around $60 to $80 per month. That monthly fee covers the company checking your saved breath-test results and making sure the device still reads alcohol as it should.
The longer you keep the device, the more you'll pay in total. Type in the months you need in the cost tool and it will show your total.
If money is tight, ask about help when you book. Drivers who can't pay for the device can turn to interlock companies in most states, or to a state fund, for help.
Comparing nine companies
Not every company is near you, since each one only covers certain states. In the table you'll find each company's listed price, the number of states it covers and its Trustpilot score (Trustpilot is a review site). Full comparison of the nine.
| Company | Listed price | States | Trustpilot |
|---|---|---|---|
 Smart Start | from $59.99 a month | 48 + DC | |
 Intoxalock | from $54.99 a month | 48 | |
 LifeSafer | $50 to $120 a month | 47 | |
 Dräger (RoadGuard Interlock) | Quoted by phone | 32 + DC | |
 Low Cost Interlock | from $78.76 a month | 31 | |
 Guardian Interlock | $50 to $120 a month | 31 | |
 Alcohol Detection Systems (ADS) | Quoted by phone | 29 | |
 ALCOLOCK | $60 to $90 a month | 24 | |
 Monitech | Quoted by phone | 1North Carolina |
From installation day to removal
Having it installed
Compare prices by company, then book with a service center in your state.
Day to day with the device
Learn what counts as a violation, what a failed test leads to, and which lockouts to expect.
Getting it removed
Find out when the device can come off, each state's rules, and what removal costs.