Common Interlock Myths That Could Put Your Licence at Risk
If you are currently enrolled in an alcohol interlock program or preparing to have a device installed, you have probably already encountered advice – from friends, online forums, social media groups, and well-meaning people who claim to have discovered clever workarounds. Some of this advice is harmless. Some of it is dangerously wrong. And some of it could extend your program, trigger enforcement action from your state transport authority, or cost you the licence you are working hard to get back.
At Guardian Interlock, we have been managing alcohol interlock programs across Australia since 1991. We work with thousands of participants every year across states and territory, and we consistently hear the same myths repeated as fact. This article addresses the most common misconceptions we encounter – and provides the accurate information you need to complete your program successfully and move forward.
Myth 1: You Can Trick the Device by Blowing Differently
This is the most persistent myth in the interlock space, and it is completely false. Guardian’s interlock device – incorporates sophisticated anti-circumvention technology that is specifically designed to detect and reject attempts to manipulate breath samples. Our device includes hum-tone detection systems that require a genuine, continuous breath exhalation with specific characteristics. The device can reliably distinguish a proper breath test from an attempt to provide an insufficient, inconsistent, or simulated sample.
Any failed or flagged test attempt is logged by the device and appears in the data downloaded at every service appointment. When your state transport authority reviews that data and identifies a pattern of anomalous test attempts, the consequences can range from an extension of your interlock period and additional conditions to reporting to the relevant authority for enforcement action. The device is designed by engineers specifically to prevent circumvention – informal advice from people who claim to have found workarounds should be treated with extreme scepticism.
Myth 2: Food and Mouthwash Won’t Affect My Reading
Interlock devices measure the concentration of alcohol in your breath using evidential-grade breath analysis technology. The device does not know whether alcohol detected in your sample came from drinking, from a vinegar-based sauce you had with dinner, from a mouthwash containing alcohol, or from a fermented food product. It measures what is present in your breath at the time of the test – and certain common products can produce genuine mouth alcohol positive readings that the device correctly identifies as alcohol.
Mouthwashes and breath sprays are among the most common culprits. Many widely available oral care products contain ethanol concentrations high enough to produce a positive interlock reading if used in the minutes before a test. Certain foods – particularly those with fermented ingredients, fruit-based products, or high sugar content – can also produce trace readings in some circumstances. The recommendation from Guardian Interlock is clear: do not eat, drink, or use any oral care products for at least 5 to 15 minutes before taking a breath test, and rinse your mouth with plain water immediately before testing. If you receive an unexpected result that you are confident is not related to alcohol consumption, wait several minutes, rinse again, and retest before concluding the device has malfunctioned.
Myth 3: A Failed Rolling Retest Will Stop My Car
This misconception causes genuine anxiety among interlock participants, and it is important to correct it clearly. Guardian’s device will never shut off a vehicle engine while it is in motion. This is a deliberate design principle, not an accident. Causing a vehicle to stop suddenly on a highway or in traffic would create a road safety hazard far more serious than the situation the retest requirement is designed to address. If you miss or fail a rolling retest while driving, the device will activate audible alarms and flash indicator lights to prompt you to take a follow-up test or safely pull over – but the vehicle will continue to operate normally until you turn the ignition off yourself.
What a failed rolling retest does do is create a logged violation in the device data that will be reviewed at your next service. A single failed retest may not have serious consequences depending on your program and the circumstances, but a pattern of missed or failed retests will be flagged in your compliance record. The practical message is straightforward: do not consume any alcohol during journeys, take rolling retest prompts seriously, and if you are prompted for a retest at an inconvenient moment, find a safe place to pull over and complete it properly.
Myth 4: Any Mechanic Can Service My Interlock
This myth has real-world consequences that are more serious than many participants realise. Using an unauthorised service centre for any aspect of your interlock – installation, calibration, service, or removal – is not merely a preference violation. It constitutes a breach of your interlock program conditions and will be reported to the relevant road traffic authority. The consequences can include extension of your interlock period, suspension of driving privileges, and other enforcement action depending on your state’s program rules.
Guardian Interlock maintains a nationally approved network of trained service centres, staffed by skilled auto electricians and mechanics who understand the specific installation, calibration, and data collection requirements of our devices. Every service appointment involves a data download, calibration verification, and program review – tasks that require both authorised equipment and trained operators. Always verify that any service centre you plan to use is listed as a Guardian-approved location before attending. Your state’s program documentation will specify this requirement.
Should you require mechanical work on your vehicle an your interlock service centre is unable to assist you can purchase a Mechanics code to allow the mechanic to work on your vehicle during this time. Contact Guardian Interlock on 02 8853 6200 to discuss your options.
Myth 5: Once the Time Period Is Up, I Am Done
Reaching the end of your interlock program’s required time period is necessary – but it is not sufficient on its own. State alcohol interlock programs are designed around the principle of demonstrated behavioural change, not simply time served. The data your device records at every service appointment throughout the program is reviewed cumulatively, and your compliance record over the full program period is what determines whether the program can be successfully completed and the device removed.
A participant who is highly compliant for the last three months of a program but has a poor compliance record for the first six months may face different outcomes than one whose compliance record is consistently clean throughout. The practical advice is simple: treat every single breath test with the same seriousness from day one of your program, not just as you approach the finish line. Your compliance record is assessed as a whole.
Myth 6: Early Removal Is a Cost-Effective Option
Some participants consider voluntary early removal of their interlock device – perhaps because circumstances have changed, because the ongoing cost feels burdensome, or simply because they want to be done. But the financial and program implications of early removal are not always what people expect. Voluntary removal incurs an Early Termination Fee. Critically, the period during which the device is not installed in your vehicle does not count towards your program completion time.
The Early Termination Fee is refunded if you have the interlock reinstalled with Guardian within six months – but if you do not reinstall within that period, the fee is not refunded. In most circumstances, completing the program with the device installed from start to finish is the most cost-effective and time-efficient path to finishing your obligations.
Get Accurate Information From the Source
The alcohol interlock program is designed to help you demonstrate sustained responsible driving behaviour and build a pathway back to unrestricted driving. Acting on inaccurate information makes that process longer and harder than it needs to be. Guardian Interlock’s team is here to answer your questions based on the actual rules and requirements of your specific program in your state – not on informal advice and speculation.
If you have questions about your program, your device, a specific test result, or anything else covered in this article, contact us directly through guardianinterlock.com.au, call our friendly team on 02 8853 6200 or visit your nearest authorised service centre. Getting the right information early is always better than dealing with complications later.
