When you get arrested for driving under the influence (DUI) in Colorado, you may then be required to install an ignition interlock device (IID) in your motor vehicle as a condition of being able to drive again.
An ignition interlock device is a breathalyzer that disables your car if you have a blood alcohol content (BAC) of .025% or more. If you fail three IID tests in a year, the Colorado DMV may extend your license suspension and require you to drive with an IID for an additional year. Below, I discuss six Colorado IID rules that you should know:
1. IIDs Required for Restricted License
If a DUI causes your Colorado driver’s license to be revoked and you wish to drive, you must apply for a restricted license with an IID. You are usually eligible for a restricted license immediately. (Before September 1, 2022, the DMV required you to wait at least one month before you could drive with an IID.)
You can be required to get a restricted license even if you avoid a DUI conviction. Your DMV case is separate from your criminal case, and you can win the criminal case and still lose the DMV hearing.
I have had clients look into buying these IIDs off of eBay or other online marketplaces, but the DMV does not allow you to buy or install one yourself. State DUI law requires that an approved Colorado ignition interlock device provider install your IID. Approved interlock providers include:
- Smart Start,
- Intoxalock,
- Guardian, and
- LifeSafer.
Only an approved provider can remove the IID as well.1 Note that before you get an IID, the court may also require you to submit to an alcohol assessment. You may also be required to obtain SR-22 insurance.
2. Failing IID Breath Tests Has Penalties
Your ignition interlock device allows you to operate your car only if your blood alcohol content (BAC) is below 0.025%. Depending on your case, failing even one time could cause your probation and restricted license to be revoked.
Otherwise, for every three breath tests that you fail in 12 months, the Colorado DMV will extend your interlock requirement for an additional year. If you choose not to extend your IID lease for that extra year, the DMV will revoke your license instead, preventing you from driving at all during the revocation period.2
As I tell my clients, IIDs are just machines, and they can malfunction. If they report false positives, we can fight it. You are always entitled to a DMV hearing to contest the extension of an interlock restriction.
3. Tampering with IIDs Is a Crime
If you are caught tampering with your ignition interlock device, your restricted license will be revoked by the Colorado DMV. You will then have to serve the remainder of the license revocation without driving at all.
Tampering comprises:
- removing the IID,
- altering the IID in any way,
- having a non-driver provide a breath sample, or
- violating any other interlock restrictions.
I always remind my clients that IIDs have cameras. So if you try to outsmart the device, your actions will be documented. The state can then use that evidence against you.
Tampering is also a class 2 misdemeanor under C.R.S. 42-2-132.5, carrying up to 120 days in jail and/or up to $750 in fines.3 This is in addition to any penalties you may have for the underlying DUI conviction, as the following table shows:
| DUI Offense | Colorado Penalties |
| First-time DUI or DUI per se | Misdemeanor:
If your blood alcohol concentration (BAC) was at least 0.15%, you are labeled as a persistent drunk driver (PDD) and sentenced as a repeat-DUI offender. |
| Second-time DUI or DUI per se | Misdemeanor:
|
| Third-time DUI or DUI per se | Misdemeanor:
|
| Fourth or subsequent DUI or DUI per se | Class 4 Felony:
|
4. You Pay For the IID
If you have an IID-restricted license in Colorado, you are responsible for paying the costs of installing and maintaining the ignition interlock device. In general, interlock lease agreements cost
- up to $200 for the installation and
- up to $90 a month to maintain (bringing the car to the provider for regular calibrations).
However, you may be eligible for financial assistance to get an IID if you are:
- A first-time DUI offender or designated as a persistent drunk driver (PDD);
- A U.S. citizen;
- A Colorado resident;
- At least 21 at the time of the DUI; and
- At the poverty level (“indigent”) as shown by state tax returns.4
High costs are one of the reasons I fight so hard to get DUI cases dropped in both criminal court and at the DMV. Between fines, court costs, and the prices of alcohol evaluations, DUI School, SR22 insurance, and IIDs, defendants can find themselves out of several thousand dollars.
See our related article, How much does an interlock cost in Colorado?
5. Early IID Removal Is Possible
You may be able to get your IID removed early in Colorado if you:
- Are a first-time DUI offender;
- Had a blood alcohol content (BAC) of less than 0.15% as measured by the DUI chemical test;
- Were at least 21 at the time of the DUI;
- Are a Colorado resident; and
- Were in full compliance with all ignition interlock requirements for four consecutive months.
A first-time DUI typically triggers a nine-month-long license revocation. Therefore, if you use the IID perfectly for the first four months, you can then get the IID removed five months earlier than you could have otherwise.
I always tell clients to drive “with a halo” and not to get complacent. You can be one day shy of the four-month mark, and one little slip-up will start the clock all over again.
If you are a repeat DUI offender or a persistent drunk driver, you are never eligible for an early IID removal.5
6. IIDs Have Cameras
IID devices are equipped with a camera that captures an image of you while collecting a breath sample from the device. This way, the camera will record whether you are trying to trick the IID by having someone else blow into it.
One question I hear is, “How good really is the IID camera quality?” The answer is that it has gotten a lot clearer since when I first started practicing law.
So, as I discussed above, do not attempt to outsmart the IID: It will only result in the revocation of your restricted license in Colorado. Plus, you face class 2 misdemeanor tampering charges, carrying up to 120 days in jail and/or up to $750 in fines.6
Frequently Asked Questions
Do I absolutely have to get an interlock device after a DUI in Colorado?
If your license was revoked due to a DUI or a refusal to take a chemical test and you want to legally drive again, yes. You must apply for an ignition interlock-restricted license and have an approved device installed in your vehicle before your driving privileges will be reinstated.
IIDs are a pain, but you get used to them pretty quick. Plus if you are struggling with alcoholism, they can really help you stay safe while getting treatment.
What happens if I fail the interlock breath test?
If you blow a BAC of 0.025% or higher, the device will temporarily lock your ignition so you cannot start the car. If the Colorado DMV receives reports that you failed a breath test in three separate months within a 12-month period, your mandatory interlock restriction will be extended by an additional year.
One piece of advice I give everyone: Do not put anything in your mouth with the slightest bit of alcohol. This includes everything from mouthwash to cough syrup to liqueur chocolates. The IID *will* pick up on the alcohol, and you will get dinged even if you had no drinks.
Can I get my ignition interlock device removed early?
Yes, but only if you are a first-time offender who had a BAC under 0.15%. If you meet those qualifications and go four consecutive months with a perfect record—meaning no failed tests, missed calibrations, or tampering events—the Colorado DMV will allow you to remove the device early.
Definitely apply for early removal as soon as you are eligible. IIDs can malfunction and return inaccurate results: The sooner you get them out of your car, the sooner you do not have to worry about false positives setting you back.
Repeat offenders and “persistent drunk drivers” are not eligible for early removal.
What is the penalty for tampering with an interlock device in Colorado?
Tampering with, altering, or having someone else blow into your IID is a class 2 misdemeanor. If caught, your restricted license will be immediately revoked for at least a year, and you can face up to 120 days in jail and up to $750 in fines.
I tell people to never touch the machine unless they are providing a test sample. Remember, IIDs have cameras. The people who read the images may misconstrue innocent actions (like cleaning) as tampering.
What is Colorado House Bill 26-1242?
HB 26-1242, known as the “Interlock Device for Impaired Drivers” bill, takes effect in Colorado on June 1, 2027. Its primary goal is to improve road safety by moving Colorado closer to a “universal interlock” system, ensuring that almost anyone convicted of a DUI must use an ignition interlock device before they can legally drive again.
Under current law, some first-time DUI offenders can choose to simply “wait out” their 9-month license revocation period by not driving, and then reinstate their license later without ever installing an interlock device. If HB 26-1242 passes, it closes this loophole. First-time offenders would be strictly required to hold an interlock-restricted license and actually use the device before getting their full, unrestricted driving privileges back.
Currently, if you refuse a chemical test (like a breathalyzer) during a DUI stop, Colorado law makes you wait two full months before you can even apply for an interlock-restricted license. This bill would eliminate that mandatory waiting period entirely, allowing those drivers to immediately install an interlock and continue driving to work or school.
HB 26-1242 also would expand the financial assistance program for lower-income drivers. It sets clear eligibility for anyone making under 150% of the federal poverty level or enrolled in public assistance programs. If you are eligible, certified interlock manufacturers would be legally required to provide free or discounted installation and removal, plus a 50% discount on the monthly lease charges.7
Additional Resources
For more information, refer to these Colorado DMV websites:
- Ignition Interlock Restricted License – Overview of how you can continue driving with an IID in your car.
- Early Reinstatement (Interlock) – How you can get your IID removed early.
- Approved Interlock Vendors – List of where you can get IIDs recognized by the courts.
- Financial Assistance for Ignition Interlock – Information on how to get financial help to pay for IIDs.
- SR-22 and Insurance Information – Current laws on when you need proof of financial responsibility and for how long.
See our related article about medical exemptions for IIDs.
Legal References
- Approved Interlock Devices, Colorado Department of Revenue, Division of Motor Vehicles.
- C.R.S. 42-2-132.5. Ignition Interlock Restricted License, Colorado DMV. SB21-055.
- C.R.S. 42-2-132.5(11). Prior to March 1, 2022, tampering with an IID was a class 1 misdemeanor carrying a minimum of 6 months in jail and/or fines of up to $500. SB21-271.
- Financial Assistance for Ignition Interlock, Colorado DMV.
- Interlock, Colorado DMV.
- See note 3.
- HB26-1242 (2026).