What Does an Interlock Report Look Like: Entries, Violations, Lockouts

An ignition interlock report looks like a chronological event log — closer to a spreadsheet than a narrative — listing every breath test, engine start, engine stop, retest, and alert the device recorded since your last service download, each line stamped with a date and time. There is no single national format. Every manufacturer designs its own layout and every state sets its own rules for what gets reported, so two reports can look noticeably different while capturing the same kinds of events. What they share is a core set of data: breath alcohol readings, pass or fail outcomes, engine activity, and flags for anything the device considers suspicious.

What’s on the Report

Federal specifications require every interlock device to log, at minimum, all start attempts and their outcomes, the breath alcohol concentration for each test, rolling retests, calibration checks, and any evidence of tampering or circumvention, all in chronological order by date and time.¹ Beyond those minimums, most reports also include:

Driver identification: your name, date of birth, driver’s license number, and state.
Device details: the unit’s serial number, software version, and the date range covered by the report.
Breath alcohol readings: the exact concentration measured at each test, whether at startup or during a rolling retest.
Engine activity: when the engine turned on, when it turned off, and whether the starter was activated or blocked.
Service history: the date of the last calibration, the date of the next scheduled appointment, and whether the device was functioning correctly at the previous service.
Violation events: failed tests, missed retests, lockouts, power disconnections, and circumvention alerts.

Many modern devices also include a camera that photographs whoever provides the breath sample, and some units have GPS. Whether those features appear in your report depends on your state’s requirements and your provider’s equipment.

What a Log Entry Looks Like

The log reads one action per line, in sequence. Federal model specifications illustrate a normal drive cycle like this:

Date → Time → “start attempt. sample accepted. BrAC 0.000. starter active.”
Date → Time → “engine on.”
Date → Time → “retest. sample accepted. BrAC 0.000.”
Date → Time → “engine off.”

A failed startup reads differently. If the device detects alcohol, the entry might say “start attempt. sample accepted. BrAC 0.030. warning given.” No “starter active” line follows, because the vehicle was blocked from starting. If you wait and provide a clean sample afterward, the log picks up with a new start attempt showing an acceptable reading.¹

Circumvention attempts leave a trail too. If someone tries to start the vehicle without providing a breath sample, the log records something like “ignition keyed. warning given. starter not active. engine on. warning given.” That “engine on” with no accepted sample before it is a red flag that the vehicle was push-started or otherwise bypassed.

Entries That Count as Violations

Not every event on the report is a violation. A clean startup and a passed rolling retest are routine entries that show compliance. The entries that draw attention from whoever is monitoring your case fall into a few categories:

Failed startup test: alcohol detected above the setpoint when you try to start the vehicle. Most states set that threshold at 0.02 BrAC, though a few use 0.025.²
Failed rolling retest: alcohol detected during a random retest after the engine is already running.
Missed rolling retest: the device prompted a retest and you didn’t provide a sample in time.
Circumvention alert: the device senses the head unit was disconnected while driving, or the vehicle was started without an accepted breath sample.
Tampering: physical interference, blocked airflow, or an attempt to use a filtered or artificial sample. The log may note “low temp” if the sample doesn’t match normal human breath.¹
Power disconnection: the device lost power, which can indicate someone disconnected the battery to reset the unit.

Some states treat a single failed test as a minor event and only escalate consequences when patterns emerge. Others treat any reading above the setpoint as a full violation regardless of context. Your state’s program rules decide which of these entries actually count against you and which are flagged as informational.

Rolling retests deserve a quick note because they trip people up. The device requests them at random after you’re already driving, signals you with an audible tone, and expects a sample. If you fail one, the vehicle will not shut off while moving; the failure gets logged and may trigger the horn or lights. If you simply don’t provide a sample in time, that becomes its own entry on the report, labeled as a missed retest. Short trips are where missed retests pile up unnoticed.

Lockouts on the Report

When the report shows a “lockout,” it means the device prevented the vehicle from starting. There are two kinds, and the distinction matters when a reviewer reads your log.

A temporary lockout happens after a failed breath test. You wait a set number of minutes, then try again. A second failure usually extends the wait, and a third failure in some states can lock you out for hours. Temporary lockouts clear on their own once the timer expires and you provide a clean sample.

A service lockout is more serious. It does not clear with time. The device stays locked until you bring the vehicle to your provider’s shop. Service lockouts are usually triggered by repeated violations, a tampering alert, or a missed calibration appointment. Both kinds appear in the report with timestamps, and a monitoring authority reviewing the log will see exactly what triggered each one.

Why Two Reports Can Look Different

A federal study found that with ten to twelve interlock companies marketing devices, each with different operational features, and each state certifying an average of five to six vendors under its own reporting requirements, the result is a “vast lack of uniformity in reporting.” Providers arrange the same information differently, define key terms differently, use different violation-filtering methods, and deliver reports through different channels: online portals, email, fax, or paper mail.³

A “violation” on one provider’s report may not match the same term on another’s. Lockout thresholds vary by state. Some states use the interlock to enforce complete abstinence, a stricter standard than the device was originally designed for. When each private company independently defines what counts as a circumvention event or a lockout trigger, you end up with a patchwork of definitions.³ If something on your own report doesn’t make sense, your provider’s technician is the best first resource for translating the codes specific to your device.

Who Gets the Report and When

Your interlock data does not stay between you and the device. The report is transmitted to whoever is overseeing your case. The state motor vehicle agency is the most common recipient. If a court ordered the interlock, your probation officer or the court itself may receive reports. In some programs, a treatment provider monitoring your progress also gets access.

The summary-level versions those authorities review typically break the data into counts: total events since the last service, startup successes, startup failures with the highest BAC recorded, retest successes, retest failures, lockout events, and tampering or circumvention events.³ Some authorities also want narrative summaries describing patterns of use, BAC readings over time, and whether the device was functioning correctly at the last check.

Reports are built from data downloaded at your regular service appointments, which happen every 30 days in most states and every 60 days in others. The technician connects to the device, pulls the complete event log, recalibrates the sensors, and checks for physical signs of tampering. Your provider then transmits the data onward. Some newer devices with cellular modems send data in near real-time, so a failed test or tamper alert can reach the monitoring authority before your next service visit. Missing a service appointment is itself a violation that appears on the report.

False Readings and How They Appear

The device measures alcohol in your breath but does not know where that alcohol came from. Mouthwash is the most common cause of a false reading, since many brands contain 14 to 27 percent alcohol, and even without swallowing it the residue in your mouth can take 15 minutes or more to dissipate. Hand sanitizer, some breath sprays, and certain medications contain alcohol that can register as well.

If you get an unexpected reading, rinse your mouth thoroughly with cold water, wait several minutes, and test again. A second clean test shortly after a failed one actually helps your case, because it suggests residual mouth alcohol rather than intoxication. The report will show both readings with timestamps, and a reviewer can see the initial reading dropped to zero within minutes, which is inconsistent with someone who has been drinking.

Prevention is simple: switch to alcohol-free mouthwash, avoid hand sanitizer right before testing, and wait at least 15 minutes after eating or using any oral product before providing a sample. A false reading still lands on the report and still has to be explained.

Challenging a Violation

If a violation appears on your report that you believe is wrong, you can generally contest it through your state’s administrative process. The usual approach is a written explanation to the state motor vehicle agency describing the event, why you believe it was a false reading, and any supporting evidence like a receipt showing a mouthwash purchase or a negative alcohol urine test taken shortly after. You may also be able to request an administrative hearing to present your case in person.

Act quickly. If your monitoring authority reviews the report and takes action before you’ve contested the entry, reversing that action becomes harder. Some drivers get an independent alcohol test, a urine screen for EtG and EtS metabolites, immediately after a false positive to establish that they had not been drinking. That kind of evidence can be persuasive at a hearing. If your driving privileges are seriously at risk, a defense attorney familiar with interlock programs in your state is worth consulting.

1
U.S. Department of Transportation. Model Specifications for Breath Alcohol Ignition Interlock Devices
2
National Highway Traffic Safety Administration. Ignition Interlocks – What You Need To Know
3
National Highway Traffic Safety Administration. Interlock Data Utilization