Interlock FAQ

Alcohol interlock devices are designed to help prevent drink driving. They stop a vehicle from starting if alcohol is detected and help drivers separate drinking from driving as part of the NSW Alcohol Interlock Program.

If you cannot start the car the morning after drinking, there may still be alcohol in your system from the night before. It is best to wait longer before attempting another breath test. If the problem continues, contact your interlock provider for advice.

If your interlock licence expires and is not renewed in time, you may no longer be able to continue in the program. This can lead to the remaining disqualification period being reimposed, so it is important to renew your licence before the expiry date through Service NSW or the relevant authority.

Yes, but only if that vehicle is fitted with an approved and properly functioning alcohol interlock device and you are allowed to drive it under your licence conditions.

Other drivers can use your vehicle, but they must follow the interlock requirements while driving it. Any failed tests, misuse or violations recorded by the device may affect your participation in the program, so it is important that anyone using the vehicle understands the rules.

If you are caught drink driving or driving a vehicle that is not fitted with an interlock when your licence requires one, you may be charged and required to attend court. Penalties can include fines, licence cancellation, further disqualification and other legal consequences.

Interlock devices must only be installed, serviced and removed by an approved interlock installer. Unauthorised installation or removal may be an offence and can lead to penalties as well as problems with your program compliance.

The tamper label must remain intact unless it is being replaced or removed by an approved service provider. If the sticker becomes damaged or unreadable, contact your provider straight away so it can be replaced correctly.

Tampering with an interlock device is a serious offence. The device records attempts to interfere with it, including failed starts, test results and certain irregular events. Tampering can lead to penalties, lockouts and possible impacts on your licence or participation period.

Interlock devices are designed with anti-tampering measures such as seals, programmed retests and breath sample detection features. They are built to make circumvention difficult and to record suspicious activity.

The device may require random retests while the vehicle is being driven, which helps ensure the person driving remains alcohol-free. Any attempt to avoid the program rules can lead to serious consequences.

No. There is generally no minimum amount of driving required simply because the device is installed.

If you miss a scheduled service appointment, the interlock may enter a countdown or lockout period depending on the device and program settings. Contact your provider immediately if you cannot attend so they can advise you on the next steps.

Your provider will usually arrange the closest suitable business day, but you should contact them early to make sure your service is completed within the allowed timeframe.

If the device appears to malfunction, contact your approved interlock provider or service centre straight away. In some cases the issue can be resolved over the phone, while other cases may require inspection.

Prescription medication is not usually a problem on its own, but some products such as mouthwash, medicines or foods may contain alcohol. To reduce the chance of a false reading, wait at least 10 minutes after using products that may contain alcohol before providing a breath sample.

If your financial circumstances change, you may be eligible for financial assistance under the NSW interlock program. Speak with your approved provider or check the current NSW Government eligibility requirements for assistance.

Before changing vehicles, you should contact the relevant authority and your interlock provider. The device must be removed from your current vehicle by an approved installer and installed in your new vehicle before you are legally allowed to drive it.

Interlock participation rules may restrict you to certain classes of vehicles only. In many cases, drivers in the program are limited to Class C vehicles. You should confirm your exact licence conditions with the NSW authority handling your interlock participation.

Motorcycles are generally not part of the alcohol interlock program. If you also hold a Class C licence, you may be able to participate by driving an approved car fitted with an interlock, but not by riding a motorcycle.

Depending on your previous licence classes, disqualification period and current licensing rules, you may need to complete knowledge or driving tests before additional classes are reissued. Check the current NSW requirements that apply to your situation.

If you have another suspension or licensing issue before entering the interlock program, you should contact Service NSW or Transport for NSW to clarify how it affects your eligibility.

Outstanding fines or other restrictions may affect your ability to deal with licensing matters. It is important to clear any issues with the relevant NSW authority before starting the program.

The device requires a proper breath sample. If you have a medical or respiratory condition that makes this difficult, speak with your doctor and your interlock provider before entering or continuing in the program.

Not necessarily. In general, you can enter the program after your disqualification period ends, provided you still meet the timing and eligibility requirements that apply to your case.

Timing matters. If your required documents or certificates are dated outside the accepted timeframe, your application may be refused and you may need to obtain updated documents again.

Moving interstate can affect your participation because interlock conditions are tied to NSW licensing rules. In many cases, leaving NSW may result in you withdrawing from the program and having the remaining disqualification period reapplied. Always check with the relevant authority before relocating.

You may be able to supervise a learner driver if the vehicle is fitted with an approved interlock device and you comply with your licence conditions. It is generally recommended that you, as the supervising driver, provide the required breath samples.

If your vehicle breaks down and you cannot keep using it, you should speak with the relevant authority and your interlock provider straight away. Depending on the circumstances, you may need approval to remove the device, transfer it to another vehicle or withdraw from the program.