Installation and equipment costs vary by state and provider, typically ranging from $70 to $150 for the initial setup
An interlock device is a breath-testing instrument wired into your vehicle's ignition system. It prevents the engine from starting if it detects alcohol on your breath. The cost to install one depends on who installs it, what your state requires, and whether you're buying or renting the device.
Most states allow you to choose from a list of certified service providers. Installation itself usually costs $70 to $150, though some providers bundle this into a first-month fee. A few states cap installation costs by law; others do not. If you're required to have an interlock, the court order or DMV notice will tell you which providers are approved in your area and whether any cost limits explore.
The device itself is almost never sold to you outright. Instead, you rent it from the service provider for the duration of your requirement — typically one to three years depending on your conviction and state law. That rental cost is where most of your ongoing expense comes from.
Key Takeaways
- Installation fees range from $70 to $150 in most states, though some states set lower caps or include installation in the first month's rental cost.
- Monthly rental fees typically run $60 to $100, and you pay this for every month the device is required, not just the months you drive.
- Calibration checks (usually monthly or every two months) cost $0 to $30 per visit depending on your provider and state rules.
- Violations — failed breath tests, missed appointments, or tampering — can add $100 to $300 in additional fees and extend your requirement period.
- Some states allow you to remove the device early if you meet certain conditions, while others enforce the full court-ordered period regardless of behavior.
Monthly rental and calibration fees are the largest ongoing cost
Once installed, you pay a monthly rental fee to keep the device in your vehicle. This typically ranges from $60 to $100 per month, though some providers charge as little as $50 and others as much as $120. The fee covers the device itself, customer support, and data transmission to the monitoring service.
On top of the rental, most states require periodic calibration checks. These are appointments where a technician verifies the device is working correctly and downloads your breath-test history. Calibration visits usually happen every 30 or 60 days. Some providers charge $0 to $15 per visit; others charge $20 to $30. A few states prohibit charging for calibration, so check your state's rules before signing a contract.
If you're required to have an interlock for two years, you'll pay the monthly rental for 24 months whether you drive every day or not. Some people try to avoid this by not driving, but most states require you to keep the device installed for the full court-ordered period. Removing it early or tampering with it can result in criminal charges.
Violation fees and penalties add up quickly
A violation occurs when you fail a breath test, miss a scheduled calibration appointment, or attempt to tamper with the device. Each violation typically costs $100 to $300 in fees and is reported to the court or DMV. Depending on your state and the number of violations, you may face:
- Extension of your interlock requirement by several months or years
- License suspension or revocation
- Criminal charges for tampering
- Increased monitoring requirements (more frequent calibration visits)
- Reinstatement fees to restore your driving privileges
A single failed breath test does not automatically end your requirement, but multiple failures can. Most states allow a small number of violations before escalating consequences. Your service provider will explain their specific violation policy when you sign up.
Missed calibration appointments are common and costly. If you forget or cannot make an appointment, contact your provider when ready. Some allow rescheduling without penalty; others charge a missed-appointment fee and report it to the court.
State-by-state cost differences and caps
A handful of states set maximum fees for interlock services. For example, some states cap installation at $100 or monthly rental at $75. Others allow providers to set their own prices. Before you contract with a provider, ask whether your state has cost limits and request a written fee schedule.
States also differ in who pays. In most cases, you pay all costs. However, some states allow you to request a fee waiver if you demonstrate financial hardship. The court or DMV will tell you how to request one and what documentation you need.
A few states require providers to offer payment plans, allowing you to spread the cost over several months rather than paying the full amount upfront. Ask your provider whether this option is available.
Total cost over a typical requirement period
To estimate your total cost, multiply your monthly rental fee by the number of months you're required to have the device, then add installation, calibration visits, and a buffer for potential violations.
For a two-year requirement with a $75 monthly rental, $100 installation, and $15 per calibration visit (12 visits per year), your baseline cost would be roughly $1,980. If you add two violations at $150 each and a few missed appointments, you could reach $2,300 to $2,500. For a one-year requirement, expect $900 to $1,300. For three years, expect $2,700 to $3,500.
These are estimates. Your actual cost depends on your state, your provider, how many violations occur, and whether you may have access to for any fee reductions. Always ask for a complete written fee schedule before you sign anything.
How to find approved providers and compare costs
Your court order or DMV notice will list approved interlock service providers in your area. Contact at least two or three and ask for their complete fee schedule in writing. Compare:
- Installation fee
- Monthly rental cost
- Calibration visit cost and frequency
- Violation fees
- Whether they offer payment plans
- Customer service hours and availability
Some providers offer discounts for upfront payment or for bundling services. Others charge more but have more convenient locations or longer customer service hours. The cheapest option is not always the best if the provider is far from your home or work, or if their service is poor.
Once you choose a provider, you can usually switch to a different approved provider later if you're unhappy, though you may have to pay a removal fee and a new installation fee. Check your contract for the switching policy.
Early removal and cost recovery options
In some states, you can request early removal of the interlock device if you meet certain conditions — typically a clean driving record (no violations) for a set period, usually three to six months. Early removal can save you hundreds of dollars in rental and calibration fees.
To request early removal, contact your service provider or the court/DMV that ordered the device. You'll need to provide proof of a clean record and may need to pay a removal fee (usually $50 to $100). Some states grant early removal automatically if you meet the conditions; others require you to file a formal petition.
If you paid for the device upfront or paid more than necessary, you generally cannot recover the cost. Rental fees are non-refundable once the device is installed. However, if a provider overcharges you or violates state fee caps, you may be able to file a complaint with your state's DMV or attorney general's office.
Frequently Asked Questions
Can I remove the interlock device myself to save money?
No. Removing the device yourself is tampering, which is a crime. It will result in additional criminal charges, license suspension, and an extended interlock requirement. Always use an approved provider for removal.
Do I have to pay for the interlock if I don't drive?
Yes. Most states require you to keep the device installed and pay the monthly rental for the full court-ordered period, even if you don't use your vehicle. Some states allow you to request a hardship exemption, but this is rare and requires court approval.
What happens if I can't afford the monthly payments?
Contact your service provider and ask about payment plans or hardship options. Some providers offer reduced fees or extended payment schedules. You can also request a fee waiver from the court if you can document financial hardship, though approval is not may provide.
Will my insurance cover interlock costs?
No. Auto insurance does not cover interlock device costs. You are responsible for all fees. However, some employers or nonprofits offer information programs for people with interlock requirements; ask your service provider whether any are available in your area.
Can I switch providers if I find a cheaper one?
Yes, you can usually switch to a different approved provider, but you'll pay a removal fee from your current provider and an installation fee to the new one. These fees often offset any monthly savings, so compare the total cost before switching.