Do I have to get a Ignition Interlock after DWI charges?

Most people have heard of the ignition interlock device in NC.  It’s also occasionally called the IID by the general public or even the Blow and Go or in-car breathalyzer.  The interlock is a breath testing device that’s installed in your car that measures alcohol in your breath and electronically records the BAC reading.

Its purpose is to ensure you’re not drinking and driving.  If you have alcohol on your breath, the vehicle won’t start.  If you keep trying to start your car after consuming alcohol, eventually that will result in a “lock out” and possible administrative action by the Division of Motor Vehicles.

If you have questions about whether a “blow and go” is required, we recommend you speak to an experienced attorney immediately.  Timing is often key in such matters.

When is an interlock required?

Either as a condition of restoration or pursuant to a Limited Driving Privilege, an Interlock is required if you are convicted of an NC DWI and your blood or breath reading was a .15 or higher.

There are normally two instances where you may be required to have the blow and go installed:  When there is a high BAC in DWI charges (.15 or higher) or as a condition of restoration by NC DMV –  Bill Powers, NC DWI Attorney 

If you have questions about how the IID works, when it’s required, or breath testing relative to BAC, give us a ring.  Our Carolina DWI defense attorneys are here to help.

What is an Ignition Interlock?  

The Ignition Interlock in North Carolina is used by both our courts and NC DMV to confirm motorists are not driving with alcohol in their system.  There are several different reasons an interlock may need to be installed.

A Limited Driving Privilege (Limited Privilege) is always discretionary.  That means the District Court and even Superior Court Judges are not required to grant a privilege to drive.  After a DWI in NC, it’s up to the judge whether to grant a Limited Privilege.

You may find it helpful to check out the NC DWI laws.

There are pre-requisites to obtain a limited privilege that are in addition to any discretionary Order or ruling by the Judge.  Before a Judge may sign a privilege, you must otherwise be eligible for a limited driving privilege.

If you have a BAC of .15 or higher, installation of the Interlock is mandatory.  It’s also important to note, even if not required by the statute, the Court may impose the blow and go in their discretion pursuant to a suspended sentence upon imposing a judgment against you.

On top of that, the statute requires a mandatory waiting period of 45 days, with no form of limited driving privileges, if you have a BAC of .15 or higher and are convicted.  If you’re able to get your charges dismissed an interlock may not be required.

Of course, that’s subject to another condition:  You also could not have been found to be a Willful Refusal.  Clearly, this can be a complicated, if not easily confused aspect of the DWI law.  As such, we encourage you to give us a ring.

We’re here to help and for criminal charges and license restoration matters, we provide a free legal consultation.


The laws involving DWI charges are complex and carry the potential for long-term consequences.  Even being accused of “drunk driving” is embarrassing and may affect your ability to legally drive in North Carolina.

In certain instances (based on the criminal laws) NC DMV may send you a Notice of Suspension just for being charged.  Your boss (or employer) can also choose to end the working relationship, especially if you drive a company car or are on the company insurance policy.

Again, it can get complicated pretty quickly.  In certain circumstances, a suspension is mandated under the law.  For example, if you have a BAC of .08 or higher, a 30-day civil administrative revocation is mandatory.

That reading, the .08 or higher, may be the result of blood testing, breath tests, or even urine testing.  The suspension may be immediate, or it may take some, waiting for results to come back, which is often the case with blood testing.

Another way your license may be revoked is for willfully refusing to submit to a sample.  Defense attorneys may refer to that as a Willful Refusal or just a Refusal.  

Each DWI charge is different, just like each person charged with impaired driving is different.  We recommend you consult with an experienced DWI lawyer immediately.  There are often important timing issues associated with license suspensions and challenging actions undertaken for DWI charges by NC DMV.  Failure to act in a timely fashion may result in the waiver of any right or legal option to challenge a suspension or revocation or to seek administrative relief from NC DMV, or the Court.

Check out our Site Map for Answers to your questions such as: 

  • Are Checkpoints Legal?
  • What is the difference between DWI and DUI?
  • Arrested for DWI in North Carolina – What Happens Now?
  • Do I need a Criminal Defense Lawyer?
  • What are the punishments for DWI in North Carolina?
  • First Offense DWI in NC – What to Expect
  • What is a DWI Dexterity Tests?
  • What is the EYE TEST on DWI cases?
  • What is the Rising BAC Defense in Impaired Driving Charges
  • Important DWI FAQs in North Carolina


What Happens with an Ignition Interlock? 1710G

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