Why Do I Need An Ignition Interlock Device If I Have Not Been Convicted Of DUI?

Barnes & Fersten Law Firm

Barnes & Fersten Law Firm

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A new law in Tennessee requires some individuals arrested for DUI to install an ignition interlock device before their case has been resolved. This new law has many people wondering what exactly it means and how it will impact their DUI case. In this blog post, we will discuss the new ignition interlock law in Tennessee and answer some of the most common questions that people have about it. If you have any additional questions or concerns about this law, please do not hesitate to contact us for more information.


An ignition interlock device (or IID) is basically a breathalyzer for your vehicle. When an ignition interlock is installed on your vehicle, the vehicle will not operate without you blowing a negative alcohol sample into the device when it beeps for you to blow. When convicted of driving under the influence, an ignition interlock device is required for a certain amount of time, depending on your history, before you are eligible for your license to be reinstated. In Tennessee, you can get a restricted driver’s license while your license is revoked because of a DUI by receiving an order from the judge in the county where the offense was committed or where you reside. Within ten (10) days of the judge signing the order authorizing you to receive a restricted license, you must get an ignition interlock device installed on your vehicle and you obtain SR-22 insurance.

It is a common misconception that an ignition interlock is required as part of probation when you are found guilty of DUI. However, if you are convicted of DUI it is beneficial to get an ignition interlock installed on your vehicle for two reasons: (1) it authorizes you to drive on a restricted license that is not restricted by time of day or location; and (2) it authorizes you to get your license reinstated afterwards. For example, an individual who pleads guilty to a DUI first offense will lose their license for a period of one year and that individual will be ineligible to reinstate their license until an ignition interlock device was installed on their vehicle for a period of one year. As such, it is almost always beneficial to install the ignition interlock during the year that your license is revoked if you are found guilty of DUI.


Unfortunately, as of July 1, 2022, individuals arrested for DUI may be required to install an ignition interlock device on their vehicle as a pretrial or bond condition. This means that you may be required to install an ignition interlock despite “being innocent until proven guilty” and there are only limited exceptions to this new law. The law makes it mandatory as a condition of bond or pretrial release to install an ignition interlock under the following circumstances of a DUI arrest:

  • An accident occurred resulting in property damage;
  • A minor was present in the vehicle at the time of the DUI arrest;
  • Defendant’s driver license has previously been suspended for a violation of the implied consent law; or
  • The arrestee has a prior conviction of reckless driving, reckless endangerment, DUI, vehicular assault, aggravated vehicular assault, vehicular homicide or aggravated vehicular homicide.


Although it is generally mandatory if your case fits into one of the four categories listed above, there are still a few exceptions. First and foremost, the alleged offense must have involved the use of alcohol. As such, if your DUI is a prescription drug or illicit drug DUI case, rather than an alcohol DUI, your lawyer should explain the circumstances to the prosecutor or potentially the judge to avoid the mandatory ignition interlock requirement.

Second, the requirement is only mandatory in circumstances where the individual arrested for DUI wants to operate a motor vehicle. There are some circumstances where an individual arrested for DUI does not have the means to drive such as a car accident resulting in property damage that caused the vehicle to be totaled. However, in such a circumstance, it would still be mandatory for the individual to install an ignition interlock on any vehicle the individual drives. As such, although this may prevent you from having to abide by the mandatory condition initially, later you may need the ignition interlock installed if you were to get a new vehicle you intended to drive for example.

Lastly, a Defendant may argue that it is not in the best interest of justice and public policy to have an ignition interlock installed. In most cases, judges will find an ignition interlock to be in the best interest of justice and public policy simply by the legislature enacting the law. However, every individual’s situation is different and if you have a compelling reason for why it would not serve the best interest of justice to have an ignition interlock, based on specific and unique circumstances in your case, your lawyer may be able to bring it to the court’s attention. If the judge does not require you to operate a motor vehicle with an ignition interlock, “then the court shall include its order written findings on why the requirement would not be in the best interest of justice and public safety. See Tennessee Code Annotated § 40-11-118.

Significantly, if you fail to have the ignition interlock device installed within ten (10) days of being ordered by a judge to install the device as a pretrial or bond condition, or if you fail to comply with the rules of an ignition interlock by having a breath sample above a .02, the prosecutor may file a motion to revoke your bond or pretrial based on a violation of bond.


Unfortunately, ignition interlock devices are expensive. As such, you are being punished, through the requirement of paying an excessive amount of money for an ignition interlock device before you are ever convicted of DUI under the new law. However, some individuals do not make enough money to pay for an ignition interlock. An individual who is found to be indigent may have the state pay a portion or all of the cost of an ignition interlock to be paid for by the electronic monitoring indigency fund. Even individuals who hire private counsel may be found indigent. Thus, it is imperative that if you think the court may potentially find you indigent that you discuss it with your lawyer because “the court shall order the portion of the costs of the device that the defendant is unable to pay be paid by the electronic monitoring indigency fund.”


It depends on how long it takes to resolve your case. If an ignition interlock device is required as part of your bond or pretrial condition, then it will be required until the case is resolved. If your case is dismissed or reduced to an offense that does not require a loss of license, then your ignition interlock device may be removed at the time of the plea or dismissal. However, as it was discussed above, if you are convicted of DUI, although you are not required to have an ignition interlock as part of your punishment for DUI, it is required to receive a restricted driver’s license and to reinstate your license at the end of the revocation period. Thus, the length of time is a case-by-case basis dependent on the length of time it takes to resolve your case.


Our team at Barnes and Fersten is here to help if you have questions about Tennessee’s recent ignition interlock law or are facing charges for DUI. We understand how overwhelming it can be to face DUI charges, which is why we are here to provide guidance and support every step of the way. Contact our office today for a free consultation.

Attorney At Law, Managing Partner

Brandon D. Fersten is an esteemed Knoxville attorney practicing DUIcriminal defense, and juvenile law. Known for his empathetic approach and commitment to his clients, he brings a record of favorable case outcomes including dismissals and not guilty verdicts at jury trials resulting in Brandon being recognized as one of the “Top 40 Under 40” in Criminal Defense, U.S. News’ Best Lawyers: “Ones to Watch,” and Super Lawyers’ “Rising Stars”. Brandon’s professional accolades, combined with his passion for justice, position him as a reliable criminal defense advocate in the East Tennessee legal landscape.