Missouri ignition interlock & DUI requirements
Ignition interlock device rules, approved vendors, SR-22 insurance filing, and license reinstatement in Missouri, cited to the statute and the Missouri Department of Revenue, Driver License Bureau.
What Missouri law requires
Missouri's ignition interlock, SR-22, and reinstatement rules are set by the statute and agency rules cited below. The values in the tables on this page are taken from those sources and are not interpretations of how they apply to any particular case.
Primary source: Mo. Rev. Stat. § 302.440
Ignition interlock requirement
| Item | Missouri rule |
|---|---|
| IID on first offense | Required only above a high-BAC threshold |
| Minimum IID period, first offense | 6 months minimum from the date of license reinstatement (when required) |
| Minimum IID period, repeat offense | 6 months minimum from the date of license reinstatement (court may impose a longer period) |
Under RSMo § 302.440 a court MAY require an ignition interlock device for any first intoxication-related traffic offense, and SHALL require it when the person's blood alcohol content was 0.15% or more, or the person caused property damage or personal injury, or for a second or subsequent offense. The Department of Revenue states that for first-time offenders an IID is required upon conviction if BAC is at or greater than .150 or if there is personal injury or property damage.
Approved interlock providers
Vendors listed here appear on the Missouri licensing agency's approved-device list. Listing order is alphabetical and is not a ranking or endorsement. Installation locations are on each vendor's own locator.
Official approved-vendor list: Missouri agency vendor list
| Vendor | Website | Location finder |
|---|---|---|
| Alcohol Detection Systems (ADS) | Alcohol Detection Systems (ADS) website | Find a location |
| Intoxalock | Intoxalock website | Find a location |
| LifeSafer | LifeSafer website | Find a location |
| Low Cost Interlock | Low Cost Interlock website | Find a location |
| RoadGuard | RoadGuard website | Find a location |
| Smart Start | Smart Start website | Find a location |
SR-22 requirement
An SR-22 is a certificate an insurer files with the state to confirm that a driver carries the liability coverage the state requires. Some states use an FR-44 or a different form for alcohol-related offenses; where Missouri does, the sources below say so.
| SR-22 filing required after a DUI | Yes |
|---|---|
| Filing period | 2 years |
SR-22 form. The Department of Revenue requires filing and maintaining proof of liability insurance (SR-22) for two years from the starting date of the suspension or revocation. The DOR reinstatement page notes SR-22 is not required for a first-time Administrative Alcohol suspension of a driver under age 21.
Program costs
Fees set by the state are cited to the fee schedule. Vendor charges vary by vendor and are shown as published ranges with the month they were checked.
| Item | Amount | As of |
|---|---|---|
| License reinstatement fee | $45 | 2026-08-28 |
| Reinstatement fee – Administrative Alcohol, alcohol-related moving violation (DWI/BAC), refusal, Abuse & Lose | $45 | 2026-08 |
| Reinstatement fee after re-suspension for failing to maintain a required IID | $20 | 2026-08 |
| IID device pricing | MoDOT states it does not keep a pricing list; costs vary among the ignition interlock companies | 2026-08 |
Frequently asked questions
- When does Missouri law require an ignition interlock device after a DWI?
- Under RSMo § 302.440, a court may require an IID for a first intoxication-related traffic offense and must require it for a second or subsequent offense, or for any offense in which the person's blood alcohol content was 0.15% or more or the person caused property damage or personal injury. The device must be used for not less than six months from the date the driver's license is reinstated.
- How long must the interlock stay on the vehicle in Missouri?
- RSMo § 302.440 sets a period of not less than six months from the date of reinstatement. The Department of Revenue states the device must be maintained for a minimum of six months from the reinstatement date, with monitoring during the last three months; violations extend the requirement until a three-consecutive-month violation-free period is completed. A court may impose a longer IID period.
- Does Missouri require an SR-22 after an alcohol-related suspension?
- The Department of Revenue's reinstatement requirements state that a driver must file and maintain proof of liability insurance (SR-22 form) for two years from the starting date of the suspension or revocation. The DOR notes SR-22 is not required for a first-time Administrative Alcohol suspension of a driver under 21.
- What is the reinstatement fee for an alcohol-related suspension in Missouri?
- The Department of Revenue lists a $45 reinstatement fee for Administrative Alcohol, alcohol-related moving violation (DWI, BAC), refusal, and Abuse & Lose actions. Reinstatement after a re-suspension for failing to maintain a required IID carries a $20 fee, per the DOR ignition interlock page.
- Who certifies ignition interlock devices in Missouri?
- The Department of Revenue states the IID must be certified and approved by the Missouri Department of Transportation (MoDOT). MoDOT's ignition interlock page lists the approved manufacturers and devices, which must meet the standards in 7 CSR 60-2.