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After a DWI in Texas, you'll likely need an ignition interlock device to drive legally. Here's what you need to know about requirements, costs, providers, and how to complete your IID period without violations.
6-12 mo
1st Offense
Typical duration
1-3 years
2nd+ Offense
Enhanced requirement
$70-150
Monthly Cost
Average range
IID requirements can vary by county and judge. Always confirm your specific requirements with your court order or Texas DMV.
If you've recently been arrested for Driving While Intoxicated (DWI) in Texas, you likely have questions about Ignition Interlock Devices (IIDs). This article explains the IID requirements in Texas, including who needs one, the laws governing them, the costs involved, and what happens if you violate the rules.
An Ignition Interlock Device (IID) is a breathalyzer installed in a vehicle that prevents it from starting if the driver's breath alcohol concentration (BrAC) is above a pre-set limit. In Texas, IIDs are increasingly common for DWI offenders as a way to maintain driving privileges while ensuring public safety. They are installed on a vehicle's ignition system, interrupting the signal from the ignition switch to the starter solenoid if alcohol is detected.
Texas law mandates or allows judges to order IIDs in various DWI-related scenarios. The specific circumstances determine the length and conditions of the IID requirement. The requirement can arise immediately following an arrest as a condition of bond, or as a condition of probation after a conviction.
The legal authority for IID mandates is spread across several Texas codes:
Several offenses can trigger IID requirements in Texas:
The length of time an IID is required depends on the offense and the court's orders:
The Texas Department of Public Safety (DPS) certifies IID vendors operating in the state. These vendors must adhere to strict technical standards. Some approved vendors include:
Important Considerations When Choosing a Provider:
The installation process is time sensitive. For defendants released on bond, the device must be installed within 30 days of release (Article 17.441(d)).
The financial burden of IIDs falls on the offender. Costs include:
Texas law provides relief for indigent defendants. If the court determines you are unable to pay, the judge may order a waiver of the installation fee and a 50% reduction of the monthly monitoring fee (Code of Criminal Procedure Art. 42A.408(e-1)). File an Affidavit of Indigency with the court, providing evidence of income, expenses, and dependents.
The IID system is strict. Common violations include:
Consequences of violations:
An IID is often crucial for license reinstatement after a DWI.
Texas Transportation Code § 521.246(e) provides a limited exception for driving employer-owned vehicles without an IID if driving is required for your job, the employer owns the vehicle, you have no ownership interest in the company, and the employer is notified of the restriction. You must carry proof of this notification in the vehicle.
Under Code of Criminal Procedure Art. 42A.408, a judge may authorize early removal if you have completed at least half of your supervision period and have no confirmed violations during the monitoring period. You must file a "Motion to Remove Interlock Device" and obtain a signed order from the judge. Do not remove the device without a court order, even if your probation term is over, as this can lead to violations or difficulty removing the restriction from your license.
Texas requires ignition interlock devices in most DWI cases. Here's a breakdown by offense level.
| Offense Type | IID Required | Duration | Notes |
|---|---|---|---|
| 1st DWI (BAC < 0.15) | 6-12 months | May be required or optional depending on court | |
| 1st DWI (BAC 0.15+) | 12-18 months | Mandatory for high BAC | |
| 2nd DWI | 1-2 years | Always mandatory | |
| 3rd+ DWI | 2-5 years | Extended requirement, possible permanent | |
| Refusal to Test | 12-24 months | Mandatory in most states |
* Durations are typical ranges. Judges may impose longer requirements. Texas uses a 10-year lookback period for prior offenses.
Under certain conditions, you may be able to drive an employer-owned vehicle without an interlock. Requirements typically include:
Employer exemptions are being phased out in many states and may have been modified since this page was updated. Verify current Texas law with the DMV or your attorney before driving any vehicle without an interlock. Violations can result in criminal charges.
These providers are approved by the state and have installation locations throughout the area. Compare costs and services before choosing.
| Provider | Locations | Coverage | Get Quote |
|---|---|---|---|
| Intoxalock | 4,500+ nationwide | Texas approved | Compare |
| Smart Start | 2,200+ nationwide | Texas approved | Compare |
| LifeSafer | 1,700+ nationwide | Texas approved | Compare |
Links marked with "Compare" may be affiliate links. We may earn a commission at no additional cost to you.
Follow these steps to get your IID installed and start driving legally.
After your DWI conviction or administrative suspension, you'll receive documentation specifying your IID requirement duration and any conditions.
Texas requires you to use a state-certified IID provider. Major providers include Intoxalock, Smart Start, and LifeSafer, all with locations in Texas.
Installation typically takes 1-2 hours. Bring your court order, drivers license, vehicle registration, and payment. The technician will wire the device into your vehicle.
The technician will train you on proper blow technique, rolling retests, and what triggers a violation. Most failures are due to improper technique, not actual alcohol.
Return to the service center every 30-60 days for calibration. Missing a calibration appointment is a violation that can extend your requirement.
Once your IID period is complete, get documentation from your provider and the court/DMV. Don't remove the device until you have official authorization.
Often included in monthly fee
Charged for failed tests or missed calibrations
Varies by provider and duration
Common issues and how to handle them
Information sourced from Texas DMV, state statutes, and IID provider documentation. Always verify current requirements with official sources.
Verification: Requirements verified against Texas DMV and state statute standards for March 2026. Laws and requirements can change—always confirm current rules with your local DMV office.
Last updated: January 2026
An experienced DWI attorney can help you understand your IID requirements, potentially reduce your interlock period, or address violations.
Disclosure: This page contains affiliate links to IID providers. We may earn a commission if you install through our partners, at no additional cost to you. This helps support our free educational content.