For many DUI convictions, the ignition interlock device is part of getting back on the road. It is a breath-testing unit wired to your car’s ignition, and Florida sets how long you must keep it based on your offense level and the facts of your case. Here is what to expect.
| Item | Detail |
|---|---|
| First conviction | 6 months, if BAC 0.15+ or a minor was in the vehicle, otherwise at the court’s discretion |
| Second conviction | 1 year, or 2 years if BAC was 0.15+ or a minor was present |
| Third conviction | 2 years minimum |
| Fourth or subsequent | 5 years minimum |
| Cost | Installation, a monthly monitoring and calibration fee, and a lease, all paid by the driver |
| How it works | A breath sample starts the car, with rolling retests while driving, all data reported to the Department |
Interlock requirements are set by sections 316.193, 316.1937, and 316.1938, Florida Statutes. The device must be installed on every vehicle the driver owns or operates. Confirm current vendor costs before relying on a figure. Procedures and figures last verified June 2026.
How long you keep it
On a first conviction the interlock is mandatory for six months only if your reading was 0.15 or higher or a minor was in the vehicle, and otherwise is at the judge’s discretion. The periods climb from there: one to two years on a second, two years on a third, and at least five years on a fourth or subsequent, and for the longest revocations the interlock is a condition of ever driving again. The device goes on every vehicle you own or regularly drive.
What it costs and how it works
You pay for all of it, the installation, a monthly monitoring and calibration fee, and the lease. You blow to start the car, the device blocks the engine if it detects alcohol, and it requires rolling retests while you drive. Every sample, including failed or missed tests, is recorded and reported to the Department, so compliance matters, because violations tend to extend the interlock period rather than shorten it.
When the law requires it
The interlock is mandatory in more situations than people expect. Under sections 316.193 and 322.2715, a first conviction requires the device for at least six months when the breath or blood reading was 0.15 or higher or a minor was in the vehicle. A second conviction requires it for at least one year, and two years if that high-reading or minor factor is present. A third conviction carries at least two years, and a fourth or subsequent conviction at least five years. A court can also order the device under section 316.1937 as a condition of probation or a hardship license.
Living with the device
The interlock takes a breath sample before the car will start and again at random while you drive, in what are called rolling retests, and a failed or missed sample is logged. Recorded violations, tampering, or attempts to get around the device can extend the required period, and the monthly report goes to the Department. For drivers who do not own a vehicle, a continuous alcohol monitoring bracelet can sometimes stand in, a point worth raising before any interlock condition is set.
I started out as an Assistant Public Defender in Florida’s Thirteenth Judicial Circuit, in Tampa, and today I am one of six ACS-CHAL Forensic Lawyer-Scientists in Florida. I demand the formal review hearing in DUI cases and appear at the Tampa and Clearwater Bureau of Administrative Reviews offices, because that hearing protects your license and locks in the officers early. Learn more about my background.
Ignition interlock questions
When is an ignition interlock required in Florida?
On a first conviction, an interlock is mandatory for six months if your breath or blood reading was 0.15 or higher or a minor was in the vehicle, and otherwise is at the court's discretion. A second conviction requires one year, or two years with a high reading or a minor. A third requires two years, and a fourth or subsequent requires at least five years.
How much does an ignition interlock cost?
The driver pays all costs, which typically include an installation fee, a monthly monitoring and calibration fee, and a device lease. Costs vary by vendor and county, so confirm current figures with an approved provider. The device must be installed on every vehicle you own or regularly operate, not just one.
How does the interlock device work?
You blow into the device to start the car, and it prevents the engine from starting if it detects alcohol above the set limit. While driving, it requires rolling retests at random intervals. All of the data, including any failed or missed tests, is recorded and reported to the Department, and violations can extend the interlock period or trigger other consequences.
Can I get the interlock removed early?
The interlock runs for the period set by statute for your offense level, and early removal generally requires a court order and a clean compliance record. Failed tests, missed retests, or tampering can extend the requirement rather than shorten it. An attorney can advise whether a motion to remove the device is realistic in your case.
Do I need an interlock for a hardship license?
Often yes, especially for repeat offenders and for anyone reinstating after a five-year, ten-year, or permanent revocation, where an interlock of at least one to five years is required as a condition of any restricted license. The interlock requirement and the hardship license work together for multiple offenders.
Related: the hardship license, FR-44 insurance, DUI penalties by offense level, and a 0.15 or higher reading.
This page is general information about Florida law, not legal advice, and it does not create an attorney-client relationship. The Florida administrative suspension and review process is governed by sections 322.2615, 322.2616, and 322.64, Florida Statutes, and Chapter 15A-6 of the Florida Administrative Code, and license revocation, hardship, and reinstatement are governed by sections 322.271 and 322.28. Deadlines are short and the rules change, so confirm current requirements with the DHSMV or an attorney. Every case turns on its own facts, and past results do not guarantee a similar outcome.
